Olga's thesis

qx,0QPvg 1wg4Q0 yQZQP ,wgx2 xP, 4qw

x04 QB gx)Q0v-w4w0 gx)vy0x4vQP

>°

Q)kx )QyyxPh yhZh

x ,vZZw04x4vQP

vP

Lq2ZvgZ

Z^>—X//jW /~ /'j k±_W^_/j B_K^/° ~! 4j]_= 4jK' 8?X;j±=X/° X?

L_±/X_ B^!X—j?/ ~! /'j 0j*^X±j—j?/= !~±

/'j ,jJ±jj ~!

,Qg4Q0 QB Lqv)QZQLq2

x%%±~;jW

_X±%j±=~? ~ ! /'j g~——X//jj=

G G G G G G G G G G G G 1 l l ; Q C Z T \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \

xKKj%/jW

nn\?UYc*wd <V HULD99BA9B,j_? ~! /'j k±_W^_/j ZK'~~

,jKj—>j±* assa

mF3-'.1gF. l:■) 3F-H:^^:'] 'b ■)F g'3V-:/)■ 'l]F-r *1-■)F- -F3-'.1g■:'] 3-'):y:■F. l:■)'1■ 3F-H:^^:']r

HADRONIC VECTOR BOSON DECAY AND THE

ART OF CALORIMETER CALIBRATION

\ \

by

OLGA LOBBAN. B.S.

A DISSERTATION

IN

PHYSICS

Submitted to the Graduate Faculty of Tex.as Tech University in

Partial Fulfillment of the Requirements for

the Degree of

DOCTOR OF PHILOSOPHY

Approved

Accepted

Dean of the Graduate School

December, 2002

x g ( P Q 6 ) w , k w - w P 4 Z

-° _W; X=~± [_= ~?j ~ ! /'j >j=/ v K~^W '_;j K'~=j? _?°['j±jh qj _[_°= ~~9jW

~^/ !~± ?X; X?/j±j=/= _ ? W — _W j =^±j /'_/ v [_= ?~/ ~?° j_±?X?J _?W — _9X?J %±~Jj==h

>^ / _=~ j?7~°X?J —° [ ~±9 _? W '_;X?J _ J~~W /X—jh qj X= _ J±j_/ %'°=XKX=/* _ =^ % j ±>

/j_K'j± _?W _ 7~° /~ [~±9 !~±h 4'_?9= _=~ /~ 'X= [X!j !~± 'j± [~?Wj±!^ K~~9X?J*

'~=%X/_X/° _ ? W —~;Xj /_9I

6 'j? [j —~;jW /~ Bj±— X_> h v ?j;j±* j;j±* j;j± /'~^J'/ v [~^W j?W ^% X9X?J X/ =~

—^K'h v '_W =~ —^K' !^? 'j±jh x >XJ %_±/ ~ ! / ' _ / [_= /'j J±~^% ~! X?K±jWX>j !±Xj?W=

v !~^?W 'j±jh (X±=/j?h Z _ ±_' h ,_?h Z~?W±_h 4 ' j ,^Wjh ,_?Xjh (X±>°h B~±j?KX_h x—°h

q^?J g'^?Jh z z h z_K9 _ ? W /'j ['~j W X??j± K^>h x ~! /'j=j %j~%j — j_?/ —~±j /~

—j /'_? /' j° 9?~[h

4~ —° J ±_?W%_±j? /= h L_% X _?W )X/_h

4~ Qj?jh

4~ —° X?K±jWX>j > ±~ /' j ± ['~ X= /'j / ±^ j /_j?/ ~! /'j !_—X°h qj '_= W~?j =~

—^K' !~± —jh X? =~ — _?° [_°=h v? 'XJ' =K'~~* 'j W±~;j ^= /~ =K'~~ ['Xj v =_ / X?

/'j %_==j?Jj± =j_±* W~X?J —° '~—j[~±9h qj '_= _[_°= >jj? =^%%~±/X;j* X?=%X±X?J*

_?W _ >j=/ !±Xj?Wh 4 '_?9= h (XWh

4~ —° _— _\ X?J —~±?h v W ~ ? A/ 9?~[ X! v K~^ W j;j± W~ [ ' _ / ='j '_= W~?jh (?~[X?J

/' _ / v '_;j =~— j ~! —° — ~— X? —jh JX;j= — j K~^±_Jj /~ W~ _?°/'X?Jh Z'j X= /'j

=— _±/j= / _ ? W >±_;j=/ [ ~— _? v 9?~[h

4~ —° _— _\ X?J W_W h qj X= !^ ~! ^?X*^j XWj_=* _? W 'j '_= _[_°= X?=%X±jW —j

_?W j?K~^±_JjW —j /~ W~ J ±j_ / /'X?J=h v _— =~ %±~^W /~ K_ 'X— —° W_Wh

4~ >~/' — ° %_±j?/=* [ '~ =%j?/ =~ —^K' /X— j* j!!~±/ _?W —~?j° ~? —j _?W — °

>±~/'j±h - ~— _?W ,_Wh v %±~—X=j vA = /_ ± / % _° X?J /'j % X_?~ _J_X?h

4~ —° x?W°* —° >j=/ !±Xj?Wh 6 X/'~^ / — ° x?W°* v [~^W '_;j *^X/ _ ~! /'X= ~?J

_J~h v _— >j==jW [X/' ' X— h _?W v /'_?9 k ~ W !~± 'X— j;j±°W_°h

XX


.-\.CK~OWLEDG E.\IE~TS

.\Iy advisor was one of the best I could have chosen anywhere. He always looked

out for my interests and made sure that I ,vas not only learning and making progess.

but also enjoying my work and having a good time. He is a great physicist. a superb

teacher and a joy to work for. Thanks also to his wife for her wonderful cooking.

hospitality and movie talk!

\\"hen we mO\·ed to Fermilab. I never. e\·er. everthonght I would end up liking it so

much. I had so much fun here . .-\ big part of that was the group of incredible friends

I found here. Kirsten. Sarah. Dan. Sondra. The Dude. Daniel. Kirby. Florencia .. .\my.

Hung Chung. J.J . .Jack and the whole dinner club .. .\II of thC'sf' people meant more to

me than they know.

To my grandparents. Papi and Lita.

To Olene.

To my incredible brother who is the true talent of the family. He has dom• so

much for me. in so many ways. In high school. he drove us to school while I sat in

the passenger sear doing my homework. He has alwa\"S bL'en supportiw. inspiring.

and a best friend. Thanks. Kid.

To my amazing mom. I don't know if I could ever do \Vhat she has done. Knmving

that I have some of my morn in me. gives me courage to do anything. She is the

smartest and bravest woman I know.

To my amazing dad. He is full of unique ideas. and he has always inspired me

and encouraged me to do great things. I am so proud to call him my dad.

To both my parents, who spent so much time. effort and money on me and my

brother. .\[om and Dad, I promise I'll start playing the piano again.

To my Andy, my best friend. \Vithout my Andy, I would have quit all of this long

ago. I am blessed with him. and I thank God for him everyday.

11

g Q P 4 w 5 4 Z

x g ( P Q 6 ) w , k w - w P 4 Z hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh XXx y Z 4 0 x g 4 hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh ;X) vZ4 Q B 4 x y ) w Z hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh ;XX) vZ4 Q B B v k 8 0 w Z hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh X]mh vP 4 0 Q , 8 g 4 vQ P hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh mah 4 q w Z4x P , x 0 , - Q , w ) hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh u

ahm v ? / ± ~ W ^ K / X ~ ? hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh uahmhm 3 ^ _? /^ — w j K / ± ~ W ° ? _ — XK = hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh cahmha 3 ^ _ ? /^ — g '±~— ~W°?_— XK= hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh kahmhn w j K / ± ~ [ j _ 9 hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh p

nh w 5 L w 0 v- w P 4 x ) x L L x 0 x 4 8 Z hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh tnhm 4 'j L_±/XKj x K K j j ± _ / ~ ± hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh t

nhmhm L±~ /~?= hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh tnhmha x ? / X % ± ~ / ~ ? = hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh mmnhmhn g~X=X~?= hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh ma

nha 4 'j L_±/XKj , j / j K / ~ ± hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh mnnhahm 4 'j 4 ±_K9X?J Z ° = / j — hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh mu

nhahmhm ZXXK~? 1j±/j] , j/jK/~ ± TZ15' hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh mcnhahmha 1 j±/j] 4±_K9X?J g ' _ — > j ± T 1 4 5 ' hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh mpnhahmhn g j? /±_ 4±_K9X?J g ' _ — > j ± Tg4g ' hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh mb

nhaha g _ ~ ± X— j /j ± = hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh amnhahahm g j ? /±_ _? W 6_ g _~±X— j/j±= hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh amnhahaha L ^J g _ ~ ± X — j / j ± hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh an

nhahn -^~? , j / j K / ~ ± hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh aunhahnhm g j? /±_ -^~? g '_— >j±= Tgh-8' hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh aunhahnha g j? /±_ -^~? 8%J±_Wj T g - L ' hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh aunhahnhn g j ? /±_ -^~? w]/j?=X~? Tg-5' hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh ac

uh g x ) Q 0 v - w 4 0 2 hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh aruhm 6 ' _ / K_ ~±X— j/j±= — j _ = ^ ± j hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh aruha L _ ± /= ~! _ K _ ~ ± X — j / j ± hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh aruhn 4°%j= ~! K _ ~ ± X — j / j ± = hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh apuhu ZjJ— j?/_ /X~? hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh atuhc w jK/±~— _J?j/XK Tj—' ='~[j±= hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh hns

uhchm L'°=XK_ =X\j ~! j— =' ~ [ j ±= hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh nmuhcha 0j=~^/X~? ~ ! j— = ' ~ [ j ±= hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh nm

uhr q_W±~?XK = ' ~ [ j ± = hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh nauhrhm L'°=XK_ =X\j ~ ! '_W±~? ='~[j±= hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh nnuhrha v?;X=X>j j ? j ± J ° hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh nn

XXX


CO>iTE:.--.;TS

.-\CK:'.\O\VLEDG E.\ IE>iTS

.-\BSTRACT .... LIST OF T.-\BLES . LIST OF FIGCRES l. I:'-iTRODCCTIO:'-i ·) THE ST.-\~D.-\RD .\IODEL

2.1 Introduction . . . 2.1.1 Quantum Electrodynamics 2. l.2 Quantum Chromodynamics 2.1.:3 El11ctroweak .....

3. EXPERI:\IE~T.-\L .-\PP.-\R.-\TCS . :3.1 The Particle Accelerator

:3.1. l Protons . . 3.1.2 . .\ntiprotons ... :3. 1.:3 Collisions . . . .

:3.2 Tlw Partic!P Detector :3.2.1 The Tracking System

:3.:2.1.l Silicon \"PrtPX Detector (S\"X) :3.2.1.2 \"ertex Tracking Chamber (\"TX) :3.:2. 1.:3 Central Tracking Chamoer (CTC)

:3.:2.2 Calorinwters ............. . :3.2.2.1 Central and \\"all Calorimeters :3.2.:2.2 Plug Calorimeter . . . . ... .

:3.2.3 .\luon Detector ........... . :3.:2.:3. l Central .\[uon Chambers ( C\IC) :3.2.:3.:2 Central .\Iuon Cpgrade (C\[ P) . 3.:2.:3.3 Central .\[nun Extension (C\[X)

-L C . ..\LORD.lETRY ........... . 4.1 \\"hat calorimeters measure . -L:2 Parts of a. calorimeter 4.3 Types of calorimeters . . . . -t.-! Segmentation . . . . . . . . -1.5 Electromagnetic ( em) showers

4.5.1 Physical size of em showers . -t.5.2 Resolution of em showers . .

-1.6 Hadronic showers . . . . . . . . -1.6. L Physical size of hadron shm•;ers -1.6.:2 Invisible energy . . . . . .

Ill

11

vi vii ix 1 -1 -t .)

fj

-I s s s

11 12 13 L-t 15 17 19 21

:n 2:3 2-1 :2-t 2-1 25 26 26 26 ·r _, 28 30 ;31 31 32 3;3 :3:3

uhrhn w jK /±~— _J?j /XK K~— %~?j? / ~! '_W±~? = ' ~ [ j ± = hhhhhhhhhhhhhhhhhhhhhhhhhh nuuhrhu g ~ — % j ? =_ / X~ ? _?W ?~?K~— %j?=_ /X~? ° — \ > { hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh nuuhrhc g~?=j*^j?Kj= ~! ? ~ ? K ~ — % j ? = _ / X~ ? hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh nc

uhp 0 _ W X_ / X~ ? , _— _Jj v = = ^ j = hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh nruhphm 0 _ W X_ / X~ ? W_— _Jj =/^WXj= !~± /'j g- Z ;j±° !~ ±[ _±W K_~±X—jE

/j ± hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh nruhpha 0 _ W X_ / X~ ? j ] % ~ = ^ ± j hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh npuhphn , _ / _ x ? _ ° = X = hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh ntuhphu x — ~ W j /' _ / ±j%±~W^Kj= W _ / _ hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh nb

ch g x ) vy 0 x 4 vP k ) Q P k v4 8 , vP x ) ) 2 Z w k - w P 4 w , g x ) Q 0 v- w 4 w 0 Z unchm g, B L ^ J 8%J±_Wj g _ ~ ± X — j / j ± hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh uncha g, B L ^ J 8%J±_Wj /j= />j_— _ ? _ ° = X = hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh un

chahm 4 ' j K_ X> ±_ / X~? — j / ' ~ W = hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh uuchahmhm w jK/±~— _J?j/XK =jK/X~? j?j±J° = K _ j hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh uuchahmha q_W±~?XK =jK/X~? j?j±J° =K_j# - j/'~W v hhhhhhhhhhhhhhhhhhhhhhhhhhh ucchahmhn q_W±~?XK =jK/X~? j?j±J° =K_j # - j/'~W v v hhhhhhhhhhhhhhhhhhhhhhh urchahmhu q _W±~?XK =jK/X~? j?j±J° =K_j# - j/'~W v v v hhhhhhhhhhhhhhhhhhhhhhh up

chaha w ] % j ± X— j? /_ K~?=j*^j?Kj= ~! j_K' —j/ ' ^ W hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh ubchahahm ,j%j?Wj?Kj ~? /'j = /_ ± / X? J %~X?/ ~! /' j ='~[j±= h h h ubchahaha ZXJ?_ ? ~ ? X ? j _ ± X / ° hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh cs

chahn B X?_ j?j±J° ±jK~?=/±^K/X~? hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh cnchahu g~?=j*^j?Kj= !~± h z j / = hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh cuchahc g ~ ? K ^ = X ~ ? = hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh cc

chn g, B g j ? / ±_ K_~±X— j/j± = / ^ W X j = hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh ccchnhm 0 ^? v — X? X— ^— >X_= W _ /_ hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh cpchnha y _K9J±~^?W K ~ ± ± j K / X ~ ? hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh rschnhn g ~ — % _ ± X=~ ? ~! K_ X>±_ /X~? — j / ' ~ W = hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh rn

chnhnhm - j/'~W v hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh rnchnhu - j /' ~ W v v v hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh rr

chu g~?K^=X~?= hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh rprh z w 4 Z hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh rb

rhm Z/±~?J K ~ ^ % X? J K ~ ? = / _ ? / hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh rbrha q _ W ± ~ ? X \ _ / X ~ ? hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh psrhn 6 '_/ X= _ 7 j / . hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh psrhu - j_=^±X?J 7 j / = X? 'XJ' j?j±J° K ~ X = X ~ ? = hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh pm

rhuhm g ~ ? K ^ = X ~ ? = hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh pnph Z w x 0 g q BQ 0 4 6 Q E z w 4 ,wgx2 Q B 4 q w /8 xP, H y Q Z Q P Z x4

4 q w Bw 0 - v) x y 4 w 1x4 0 Q P hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh pcphm v ? / ± ~ W ^ K / X ~ ? hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh pcpha 8xa 0 j=^ / hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh pr

X;


-t.6.3 Electromagnetic component of hadron showers 3--l -t.6.-l Compensation and noncompensation ( e/ h) 3-l -t.6.5 Consequences of noncompensation . . . . . . . 35

-1. 7 Radiation Damage Issues . . . . . . . . . . . . . . 36 -l. i.l Radiation damage studies for thl' C.\IS very forward calorime-

ter . . . . . . . . . 36 -L i.2 Radiation exposure . . . . . . 37 -l. i.3 Data .-\nalysis . . . . . . . . . 38 -l. i.-l .-\ model that reproduces data 39

"· C.-\LIBR.-\TI~G LO~GITCDI~_-\LL Y SEG.\lE~TED C.-\LORD.IETERS -13

6.

5.1 CDF Plug Cpgrade Calorinwter . . . -1:3 5.2 CDF Plug Cpgrade testbeam analysis -1:3

5.2.l The calibration methods . . . . . -l-l 5.2.1.1 Electromagnetic section energy scale -l-l 5.2. l.2 Ha.Jronic section energy scale----\[Pthod [ . -15 5.2.t.:3 Hadronic section fltergy scah!-\[ethod II Ju .5.2.l.-l Hadronic section energy scale--\[ethod III . -17

5.2.2 ExpPrimental <·ons1•q11Puces of Pach methud . . . . -l!J -5.2.2.1 Dependence on the starting poiut of tlu• showers. -l!J :i.2.2.2 Signal nonlinearity . . ;j()

5.2.3 Final energy rr~coustruction 5;3 5.2.-l Consequences for .Jets . . . . 5-l 5.2.,j Conclusions . . . . . . . . . ::FJ

5.3 CDF Central calorimeter studies :):) 5.3.1 Run I minimum bias data . -1.

5.-t JETS.

5.:3.2 Background correction . . . 5.3.3 Comparison of calibration methods

-i3.:3.l \Iethod I 5.3.-l 1lethod III .

Conclusions . . . .

6.1 Strong coupling constant 6.2 Hadronization . . . . . . 6 ·3 \\"l . . •) .. iat 1s a Jet. . . . . . .

60 63 6:3 66 67 69 69 TO TO

6.-t .\Ieasuring jets in high energy collisions 71 6.-l.l Conclusions . . . . . . . . . . . 73

1. SE.-\RCH FOR T\VO-.JET DEC.-\Y OF THE o· .-\;\O Z BOSO~S .-\T THE FER1IIL.-\8 TEV.-\TRO:\ , :J

7.1 - •) '·-Introduction C .-\2 Result

lV

,5 76

phn g , B , _ / _ hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh ptphu ZXJ?_ w ] % j K / _ / X ~ ? = hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh pbphc g j?/±_ g _ ~±X— j/j± zj / g ~ ± ± j K / X ~ ? = hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh tmphr v?X/X_ =j_±K' % ± ~ K j W ^ ± j hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh tcphp g~±±jK/X?J !~± /± XJJj± X?j ! ! XK Xj?K Xj= hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh trpht 0 j = ^ / = hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh tt

phthm ZXJ?_ L ± ~ % j ± / X j = hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh ttphtha g±~== =jK/X~? _?W K~— %_±X=~? [X/' Z /_?W_±W -~Wj h h h h bs

phb g~?K^=X~?= hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh bath Z)A--x01 xP , g Q P g ) 8 Z v Q P Z hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh mspy vy ) vQ k 0 x L q 2 hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh msbxh vP 4 w 0 g x ) vy 0 x 4 vQ P Q B 4 q w ) Q P k v4 8 , vP x ) Z w k - w P 4 Z Q B x

g x ) Q 0 v- w 4 w 0 Z2 Z4w- T 0 w L 0 vP 4 w , 6 v4 q Lw0 - vZZvQ P B0Q- P 8 g ) w x 0 vP Z4 0 8 - w P 4 Z xP , - w 4 q Q , Z h xunp Tassa' ntm' h h h h mma

yh w B B w g 4 Z Q B 0 x , vx 4vQ P xP , 4 q w v0 g Q P Z w 3 8 w P g w Z BQ 0 4 q w L w 0 B Q 0 - x P g w Q B 4 q w BQ 06 x 0 , g x ) Q 0 v- w 4 w 0 Z vP 4 q w g-Z w 5 L w 0 v- w P 4 T0 w L 0 vP 4 w , 6 v4 q Lw 0 - vZZ vQ P B0 Q - P 8 g)wx0 vP Z4 0 8 - w P 4 Z xP, - w 4 q Q , Z h ymZp Tassa' r r m hhhhhhhhhhhhhhhhhhhhhhhhh mar

gh Q P 4 q w w P w 0 k 2 - w x Z 8 0 w - w P 4 Q B q x , 0 Q P hzw4Z Tx g g w L 4 w , B Q 0 L8 y)vgx 4vQ P vP P 8 g ) w x 0 vP Z4 0 8 - w P 4 Z xP , - w4q Q , Zx' hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh mua

;


7.3 CDF Data .................. . 7.4 Signal Expectations ............. . , .u Central Calorimeter .Jet Corrections .... . 7.6 I .I

i.8

Initial search procedure ........... . Correcting for trigger inefficiencies . . . . . . Results ..................... .

i.8.1 Signal Properties . . . . . . . . . . . . . . . ..... i.8.2 Cross section an<l comparison with Standard ~Ioele! ..

7.9 Conclusions . . . . . . . . . . . . . . . . .... . 8. SC>.L\L-\RY .-\\"D CO\"CLCSIO\"S .................. . BIBLIOGR.-\PHY .............................. . .-\. I\"TERC.-\LIBR.-\TIO\" OF THE LO\"GITL.DI\".-\L SEG>.IE\"TS OF .-\

C.-\LORC\IETER SYSTE.\I (REPRI\"TED \\"ITH PER.\IISSIO\" FRO.\I \"CCLE.-\R I\"STRC.\IE\"TS . ..\\"D .\IETHODS .. -\-!87 (2002) :381) ....

B. EFFECTS OF R...\DL-\TIO.\" ...\\"D THEIR CO\"SEQCE\"CES FOR THE PERFOR.\I.-\\"CE OF THE FOR\\'.-\RD C.-\LORI.\IETERS I\" THE C.\IS EXPERI.\IE\"T I REPRI\"TED \\"ITH PER.\IISSIO\" FRO.\[ \"CCLE.-\R

i8 79 81 85 86 88 88 90 92

lOi 109

112

I\"STRC.\IE\"TS .-\\"D .\IETHODS. 818, (2002) GGl . . . . . . . . . . . 126 C. O\" THE E\"ERGY .\IE.-\SCRE.\IE\"T OF H.-\DRO.\ .JETS (.-\CCEPTED

FOR PCBLIC.-\TIO.\ I\" .\L.CLE.-\R I.\STRC.\IE\"TS .-\\"D .\IETHODS .-\) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

\"

1-12

ulhdtu6d

L±j=j? /jW 'j±j _±j =j;j±_ = /^W Xj= X?;~;X?J /'j j?j±J°E — j_=^±j— j?/ ~! %_±/XKj=

^=X?J K_ ~ ±X— j/j±= h 4 'j !X±=/ = /^ W ° X?;~;j= /'j j!!jK/= ~! ±_WX_/X~? W _ — _ J j ~? /'j

±j=%~?=j ~ ! _ % ±~ /~ /°%j K_~±X— j/j± !~± /'j g ~— %_K / - ^~? Z~j?~XW j]%j±X— j?/h 6j

!~^?W /' _ / /' j j!!jK/= ~! ±_W X_/X~? W_— _Jj ~? /'j K_ ~±X— j/j± A= ±j=%~?=j _±j W~=j

Wj%j?Wj?/ _ ? W /' _ / —~=/ ~! /'j W_— _Jj [X ~KK^± X? /'j !X±=/ °j_± ~! ±^ ? ? X? J _/ /'j

)_±Jj q _W ±~? g~XWj±h x?~/'j± = /^W° X?;~;jW /'j _==j==—j?/ ~! /'j w?j±J° B~[

- j/'~W* _ ? _ J~ ± X/'— ['XK' K~—>X?j= /'j X? !~±— _/X~? !±~— /'j K_~±X— j/j± =°=/j—

X= K~— >X?jW [X/' /' _ / !±~— /'j /±_K9X?J =°=/j— X? _? _ / /— % / /~ X—%±~;j /'j j?j±J°

±j=~^/X~? !~± 7j / —j_=^±j—j?/=h 8=X?J /'j w?j±J° B~[ - j/'~W* _? X— %±~;j— j?/ ~!

< nsR X= !~^?W* >^/ /'X= X—%~;j—j?/ WjK±j_=j= _ / 'XJ' j?j±JXj= ['j?U /'j '_W±~?XK

K_ ~±X— j/j± ±j=~^/X~? W~— X?_/j= /'j *^_X/° TX! /'j 7j/ j?j±J° — j_=^±j—j?/=h

BX?_°* [j Wj;j~%jW _ ?j[ — j/'~W /~ K_ X>±_ /j _ ~?JX/^WX?_° =jJ—j?/jW

K_~±X— j/j±h 4 ' X= — j/'~W jX—X?_/j= %±~>j— = [X/' /'j /±_W X/X~?_ — j /' ~ W ^=jW !~±

/'j K_ ~±X— j/j±= _ / /'j g~XWj± ,j/LK/~± _ / Bj±—X_>h 6j _%%XjW /'X= ?j[ — j/'~W

X? /'j =j_±K' !~± '_W±~?XK WjK_°= ~! /'j !8 _ ? W ' >~=~?= X? _ =_—%j ~ ! WX7j/ W _ /_

/_9j? W^ ± X? J 4j;_/±~? 0^? vgh x =XJ?_ ~! btpn„nbcsT=°=' „mmns j;j?/= [_= !~^?W

['j? /'j ?j[ K_ X>±_ /X~? — j/'~W [_= ^=jWh 4'X= K~±±j=%~?W= /~ _ K±~== =jK/X~?

Fkk 6h ' { » o Q b B' #l $ — N 1 { f nchr „ mu ha T=°='„u hm T= /_ /' ?>h


.-\.BSTR..-\CT

Presented here are several studies involving the energy measurement of particles

using calorimeters. The first study involves the effects of radiation damage on the

response of a prototype calorimeter for the Compact :\[uon Solenoid experiment. \Ye

found that the effects of radiation damage on the ca.lorimeter·s response arc dose

dependent an<l that most of the damage will occur in the first yPar of running at the

Large Hadron Collider. .-\nor.her study involved the assessment of the Energy Flow

:\[echud. an algorithm which combines the information from the calorimeter system

is combined with that from the tracking system in an attmpt to imprO\·e tht-> enn~y

resolution for jPt measnrements. C sing thP Energy Flow ~[et hod. an imprownwnt of

""' :3orlc is found. but this impovement decreases at high PnergiPs when• the hadronic

calorimf~ter resolution dominates the quality uf tlu• jf't Pllergy measurements.

Finally. we developed a new method to calibratP a longitudinally sPgnwnted

calorimeter. This method eliminates problems with the traditional method ust•d for

the calorimeters at the Colli<ler Detector at Ft1rmilab. \\"e applied this new method

in the search for hadrunic decays of the ir an<l Z bosons in a sample of dijet data

taken during Tevatron Run IC. :\ signal of 98,3±3950(sys) ±11:30 events was found

when the new calibration method was used. This corresponds to a cross st>ction

a(pp--', Tr. Z) · B(TL Z ~jets)= 35.6 ± l-l.2(sys):::-Ll(stat) nb.

VI

i2hd r. duli5h

phm Z^——_±° ~! j!!XKXj?KXj=hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh

pha BX/= /~ /'j /±XJJj± j!!XKXj?K° K^±;j Wj±X;jW !±~— _ € j _?W X9jX'~~W !X/ /~ /'j >_K9J±~^?W ±jJX~? °00<$$ f mac E nss kj1iKa' ~! /'j ±_[ WX7j/ —_== =%jK/±^— T?~ 7j/ j?j±J° K~±±jK/X~?='h B^?K/X~?= X?;~;X?J _±K/_? _?W /_?' T=jj w*^_/X~?= phmnh phma' _±j ^=jW /~ !X/ /'j /±XJJj± j!!XKXj?K° K^±;j* _?W WX!!j±j?/ ?^—>j±= ~! %~X?/= ~? /'j j!/ _?W ±XJ'/ =XWj= ~! /'j =XJ?_ ±jJX~? _±j X?K^WjW X? /'j !X/ T/~ /'j /±XJJj± j!!XKXj?K° K^±;j'h x j?/±Xj= X? /'j /_>j K~±±j=%~?W /~ !X/= T/~ /'j /±XJJj± j!!XKXj?K° K^±;j' ['XK' '_W ±jW^KjW Mj ;_^j= j== /'_? mhmhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh

phn BX/= /~ /'j /±XJJj± j!!XKXj?K° K^±;j Wj±X;jW !±~— _ X9jX'~~W !X/ /~ /'j >_K9EJ±~^?W ±jJX~? °*<$$ f mac E nss kj1iKa' ~! /'j WX7j/ —_== =%jK/±^— X?['XK' 7j/ j?j±JXj= [j±j K~±±jK/jW ^=X?J /'j —j/'~W Wj=K±X>jW X? ZjK/X~? phch x !^?K/X~? X?;~;X?J _±K/_? T=jj w*^_/X~? phmn' X= ^=jW /~ !X/ /'j /±XJJj± j!!XKXj?K° K^±;j* _?W WX!!j±j?/ ?^—>j±= ~! %~X?/= ~^ /'j j!/ _?W ±XJ'/ =XWj= ~! /'j =XJ?_ ±jJX~? _±j X?K^WjW X? /'j !X/ T/~ /'j /±XJJj± j!!XKXj?K° K^±;j'h x j?/±Xj= X? /'j /_>j K~±±j=%~?W /~ !X/= T/~ /'j /±XJJj± j!!XKXj?K° K^±;j' ['XK' '_W ±jW^KjW Q j ;_^j= j== /'_? mhmhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh

< hu BX/= /~ /'j /±XJJj± j!!XKXj?K° K^±;j Wj±X;jW !±~— _ X9jX'~~W !X/ /~ /'j >_K9EJ±~^?W ±jJX~? T—zp f mac E nss kj1iKa' ~! /'j WX7j/ —_== =%jK/±^— X?['XK' 7j / j?j±JXj= [j±j K~±±jK/jW ^=X?J /'j —j/'~W Wj=K±X>jW X? ZjK/X~? phch x !^?K/X~? X?;~;X?J /_?' T=jj w*^_/X~? phma' X= ^=jW /~ !X/ /'j /±XJJj± j!!XEKXj?K° K^±;j* _?W WX!!j±j?/ ?^—>j±= ~! %~X?/= ~? /'j j!/ _?W ±XJ'/ =XWj= ~! /'j =XJ?_ ±jJX~? _±j X?K^WjW X? /'j !X/ T/~ /'j /±XJJj± j!!XKXj?K° K^±;j'h x j?/±Xj= X? /'j /_>j K~±±j=%~?W /~ !X/= T/~ /'j /±XJJj± j!!XKXj?K° K^±;j' ['XK' '_W ±jW^KjW Q j ;_^j= j== /'_? mhmhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh

phc BX/= /~ /'j /±XJJj± j!!XKXj?K° K^±;j Wj±X;jW !±~— _ € L !X/ /~ /'j >_K9J±~^?W ±jJX~? °00<$$ m mac # nss kj1iKa' ~! /'j WX7j/ —_== =%jK/;±^X^ X? ['XK' 7j/ j?j±JXj= [j±j K~±±jK/jW ^=X?J /'j —j/'~W Wj=K±X>jW X? ZjK/X~? phch x !^?K/X~? X?;~;X?J _±K/_? T=jj w*^_/X~? phmn' X= ^=jW /~ !X/ /'j /±XJJj± j!!XEKXj?K° K^±;j* _?W WX!!j±j?/ ?^—>j±= ~! %~X?/= ~? /'j j!/ _?W ±XJ'/ =XWj= ~! /'j =XJ?_ ±jJX~? _±j X?K^WjW X? /'j !X/ T/~ /'j /±XJJj± j!!XKXj?K° K^±;j'h x j?/±Xj= X? /'j /_>j K~±±j=%~?W /~ !X/= T/~ /'j /±XJJj± j!!XKXj?K° K^±;j' ['XK' '_W ±jW^KjW € j ;_^j= j== /'_? mhmhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh

;XX


7.1

- ·)

'·-

LIST OF T.-\.BLES

Summary of efficiencies.

Fits to the trigger efficiency curve derived from a x2 and likelihood fit to the background region (mJJ = 125 - 300 GeV /c2) of the raw dijet ma.ss spectrum (no jet energy corrections). Functions involving arctan and tanh (sL>e Equations 7.1:3. 7.12) are used to fit the trigger efficiency curve. and different numbers of points on the left and right sides of the signal region are included in the fit (to the triggP.r efficiency curve). All entries in the table correspond to fits ( to the trigger dficiency curve) which had reduced

81

x2 va.lues less than l. l. . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

,.:3 Fits to the trigger efficiency curve derived from a likelihood fit to the background region (m11 = 125 - :JOO Ge\"/c2 ) of the dijet mass sp,•ctrum in which jet energies were corrected using the method described in SPction 7.0 . . -\ function involviug arctan (sec Eq11atiuu ,. 1:3) is used to fit tilt' triggt>r efficiency curve. and different numbers uf points on the left and right sides of the signal region arc included in the fit ( to the trigger efficiency curve) . .-\II entries in the table correspond to fits ( to the trigger efficiency rnrw) which had reduced x:.! values less than l.l. . . . . . . . . . . . . . !)I)

,.--! Fits to the trigger efficiency curve derived from a likelihood fit to the background region (rn11 = 125 - 300 GeV/c"!.) of the clijt!t mass spectrum in which jet energies were corrected using the method described in Section 7.5. A function involving tanh (see Equation 7.12) is used to fit the trigger t>fficiency curve, and different numbers of points on the left and right sides of the signal region a.re included in the fit (to the trigger efficiency curve) . .-\ll entries in the table correspond to fits ( to the trigger efficiency curve) which had reduced x2 values less than 1.1. . . . . . . . . . . . . . . . . . . . . 91

, .o Fits to the trigger efficiency curve derived from a x2 fit to the background region (m11 = 125 - 300 GeV/c2

) of the dijet mass spectvrurn in which jet energies were corrected using the method described in Section 7.5. A function involving arctan (see Equation 7.13) is used to fit the trigger efficiency curve, and different numbers of points on the left and right sides of the signal region a.re included in the fit (to the trigger efficiency curve). All entries in the table correspond to fits (to the trigger efficiency curve) which had reduced x"!. values less than l. l. . . . . . . . . . . . . . . . . . . . . 92

\"ii

phr BX/= /~ /'j /±XJJj± j!!XKXj?K° K^±;j Wj±X;jW !±~— _ ° Y /~ /'j >_K9J±~^?W ±jJX~? T—Y* f mac # nss kj1AiKa' ~! /'j WX7j/ —_== =%jK/±^— X? ['XK' 7j / j?j±JXj= [j±j K~±±jK/jW ^=X?J /'j —j/'~W Wj=K±X>jW X? ZjK/X~? phch x !^?K/X~? X?;~;X?J /_? ' T=jj w*^_/X~? phma' X= ^=jW /~ !X/ /'j /±XJJj± j!!XKXj?K° K^±;j* _?W WX!!j±j?/ ?^—>j±= ~! %~X?/= ~? /'j j!/ _?W ±XJ'/ =XWj= ~! /'j =XJ?_ ±jJX~? _±j X?K^WjW X? /'j !X/ T/~ /'j /±XJJj± j!!XKXj?K° K^±;j'h x j?/±Xj= X? /'j /_>j K~±±j=%~?W /~ !X/= T/~ /'j /±XJJj± j!!XKXj?K° K^±;j' ['XK' '_W ±jW^KjW ° ;_^j= j== /'_? mhmhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh bn

php BX/= /~ /'j /±XJJj± j!!XKXj?K° K^±;j Wj±X;jW !±~— _ X9jX'~~W !X/ /~ /'j >_K9EJ±~^?W ±jJX~? TS tE f mac E nss k j1 iKa' ~! /'j ±_[ WX7j/ —_== =%jK/±^— T?~ 7j/ j?j±J° K~±±jK/X~?='h B^?K/X~?= X?;~;X?J _ ±K /_? _?W /_?' T=jj w*^_E/X~?= phmnh phma' _±j ^=jW /~ !X/ /'j /±XJJj± j!!XKXj?K° K^±;j X? _ ±jJX~? [ ' j ± j ? ~ = XJ?_ X= j ] % j K / j W * *<$$ f b s E m m s kj1iKah ,X!!j±j?/ ?^—>j±= ~! %~X?/= ~? /'j j!/ _?W ±XJ'/ =XWj= ~! /'j =XJ?_ ±jJX~? _±j X?K^WjW X? /'j !X/ T/~ /'j /±XJJj± j!!XKXj?K° K^±;j'h x j?/±Xj= X? /'j /_>j K~±±j=%~?W /~ !X/= T/~ /'j /±XJJj± j!!XKXj?K° K^±;j' ['XK' '_W ±jW^KjW ° ;_^j= j== /'_? mhmh4'j —j_? ;_^j ~! /'j ?^—>j± ~! j;j?/= !~± _ !X/= X= K~?=X=/j?/ [X/' \j±~h bEm

phZ BX/= /~ /'j /±XJJj± j!!XKXj?K° K^±;j Wj±X;jW !±~— _ ° !X/ /~ /'j >_K9J±~^?W ±jEJX~? °N0<$$ m macEnss k j1 iKa' ~! /'j ±_[ WX7j/ —_== =%jK/±^— T?~ 7j/ j?j±J° K~±±jK/X~?='h B^?K/X~?= X?;~;X?J _±K/_? _?W /_?' T=jj w*^_/X~?= phmnh phma' _±j ^=jW /~ !X/ /'j /±XJJj± j!!XKXj?K° K ^ — o X? _ ±jJX~? [ ' j ± j ?~ = XJ?_ X= j ] % j K /j W h S®E f bs # mms k~1ijah ,X!!j±j?/ ?^—>j±= ~! %~X?/= ~? /'j j!/ _?W ±XJ'/ =XWj= ~! /'j =XJ?_ ±jJX~? _±j X?K^WjW X? /'j !X/ T/~ /'j /±XJJj± j!!XKXj?K° K^±;j'h x j?/±Xj= X? /'j /_>j K~±±j=%~?W /~ !X/= T/~ /'j /±XJJj± j!!XKXj?K° K^±;j' ['XK' '_W ±jW^KjW ° ;_^j= j== /'_? mhmh 4'j —j_? ;_^j ~ ! /'j ?^—>j± ~! j;j?/= !~± _ !X/= X= K~?=X=/j?/ [X/' \j±~hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh msr


'i.6 Fits to the trigger efficiency curve derived from a x2 fit to the background region (m11 = 125 - 300 GeV/c:2) of the dijet mass spectrum in which jet energies were corrected using the method described in Section 7.5. A function involving tanh (see Equation 7.12) is used to fit the trigger efficiency curve, and different numbers of points on the left and right sides of the signal region are included in the fit (to the trigger efficiency curve). All entries in the table correspond to fits ( to the trigger efficiency curve) which had reduced x2 values less than 1.1. . . . . . . . . . . . . . . . . . . . . . . 9:3

, . , Fits to the trigger efficiency curve derived from a likelihood fit to the background region (m11 = 125 - :mo GeV jc"2) of the raw dijet mass spectrum (no jet energy corrections). Functions involving arctan and tanh (see Equations 7.13. 7.12) a.re used to fit the trigger efficiency curve in a region where no signal is expected. m 11 = 90 - 110 Ge\"/ c"2. Different numbers of points ou the left and right sides of the signal region are included in the fit ( to the trigger efficiency curve). All entries in the table correspond to fits ( to the trigger efficiency curve) which had reduced x2 values less than 1.1. The mean value of the number of events for all tits is consistent with zero. 9-1

'i.8 Fits to the trig~er efficiency curve derived from a x"2 fit to the back~ouud region (m11 = l2;j-;3()U Ge\"/c:!) of the raw clijet mass spt->ctrum (unjet euergy corrections). Functions involving arctan and tanh (see Equations 7.13. 7.12) a.re used to fit the trig;ger efficiency curve in a re~ion where no signal is expected. mJJ = !JO - 110 Ge\'/c:!. Different numbers of points on the left a.ud right sides uf the signal region are included in the fit (to the trigger efficiency curve). All entries in the table correspond to fits (to the trigger efficiency curve) which ha<l reduced x2 values less than l. l. The mean valtu) of the number of events for all fits is consistent with zero. . . . . . . . . . 106

\"111

XQ Q£

i2hd r. .23mt5h

nhm 4'j Bj±—X_> _KKjj±_/~± K~—%j]h B±~— D7 hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh bnha x /'±jjEWX—j?=X~?_ ;Xj[ ~! /'j g,B Wj/jK/~±h B±~— mmVhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh mcnhn x ;Xj[ ~! ~?j *^_W±_?/ ~! /'j g,B Wj/jK/~± ='~[X?J /'j ;_±X~^= Wj/jK/~±

K~—%~?j?/= _?W /'j g,B K~~±WX?_/j =°=/j—h B±~— D7hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh mrnhu x /'±jjEWX—j?=X~?_ ;Xj[ ~! _? Z25 >_±±jh B±~— DmVhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh mpnhc Z15 _WWj±h B±~— DmVhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh mtnhr 6'j? _ K'_±JjW %_±/XKj %_==j= /'±~^J' /'j 1A45h /'j J_= X= X~?X\jWh 4 'j

!±jjW jjK/±~?= W±X!/ /~ /'j =j?=j [X±j= ='~[?h B±~— D7hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh mbnhp g4g j?W%_/jh B±~— D7hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh asnht x mcn c [jWJj ~! /'j gj?/±_ K_~±X—j/j±h B±~— D7hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh aa

uhm Q±Xj?/_/X~? ~! /'j *^_±/\ !X>j± K_~±X—j/j± %±~/~/°%j W^±X?J /j=/>j_— = /^ W EXj= ~! /'j j!!jK/= ~! ±_WX_/X~? W_—_Jjh 4'j /~[j± ?^—>j±X?J =K'j—j ^=jW!~± /'j=j =/^WXj= X= ='~[?h 4'j WX±jK/X~? ~! /'j >j_— ^=jW /~ X±±_WX_/j /'j—~W^j T)v) yj_—' _?W /'j WX±jK/X~? ~! /'j >j_— ^=jW /~ _==j== /'j j!!jK/=~/ X±±_WX_/X~? ~? /'j K_~±X—j/j±A= %j±!~±—_?Kj Tqu yj_—' _±j ='~[?h h h nt

uha 4'j _;j±_Jj =XJ?_ X? 4~[j± c ±jK~±WjW X? KE=K_?= [X/' jjK/±~?= j?/j±X?J/'j Wj/jK/~± X? /'j ±jJX~?= 6 f s E c —— _?W 6 E as E ac ——h ±j=%jK/X;j°h nb

uhn ZX—^_/jW ±j=%~?=j K^±;j= >_=jW ~? w*^_/X~^ uhu _?W /'j W~=j %±~!Xj y°C{ _KK^—^_/jW X? /'j 6 X?/j±;_ sEc —— !~± * m s _?W WX!!j±j?/ ;_^j= ~! /'j %_±_—j/j± _ h B~± K~—%_±X=~?* /'j j]%j±X—j?/_ KE±j=%~^=j K^±;j !~±6 f s E c ——h K~?;j?Xj?/° ?~±—_X\jW* X= ='~[? _= [jh Zjj /j]/ !~± Wj/_X=h um

uhu ZX—^_/jW ±j=%~?=j K^±;j= >_=jW ~? w*^_/X~^ uhu _?W /'j W~=j %±~!Xj yC{ _KK^—^_/jW X? /'j 6 X?/j±;_ sEc —— !~± WX!!j±j?/ ;_^j= ~! /'j %_±_—j/j±= 0< _?W _h B~± K~—%_±X=~?* /'j j]%j±X—j?/_°A —j_=^±jW K^±;j X= ='~[? _=[jh Zjj /j]/ !~± Wj/_X=hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh ua

chm 4'j L^J 8%J±_Wj /j=/>j_— —~W^j K~?=X=/jW ~! !~^± mc“ =jK/X~?=* j_K'[X/' as /~[j±=h 6jWJj n [_= >^X/ ^<N>£RN _? w- =jK/X~?hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh uc

ha 4'j j?j±J° =K_j !~± /'j w- K_~±X—j/j± =jK/X~?h huh _= _ !^?K/X~? ~! j?j±J°h urhn 4'j j?j±J° =K_j ~! /'j '_W±~?XK =jK/X~?h oUB !~^?W ^=X?J -j/'~W v _= _

!^?K/X~? ~! /'j j?j±J° Wj%~=X/jW X? /'j '_W±~?XK =jK/X~? ~! /'j K_~±X—j/j± >° %j?j/±_/X?J %X~?=hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh up

chu 4'j j?j±J° =K_j ~! /'j '_W±~?XK =jK/X~?h o * B !~^?W ^=X?J -j/'~W vv _= _ !^?K/X~? ~! /'j j?j±J° ~! /'j X?K~—X?J jjK/±~?=hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh uZ

chc 4'j ±jK~?=/±^K/jW j?j±J° ~! %j?j/±_/X?J T/~%' _?W ?~?%j?j/±_/X?J T>~//~—' %X~?= ['j? -j/'~W v X= ^=jW /~ !X?W /'j ;_^j ~! o hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh cm

XhC


LIST OF FIGCRES

3.1 The Fermilab accelerator complex. From [l]. . . . . . . 9 3.2 .-\ three-dimensional view of the CDF detector. From [l]. 15 3.3 A view of one quadrant of the CDF detector showing the various detector

components and the CDF coordinate system. From [l]. 16 3.4 .-\ three-dimensional view of a.n SVX barrel. From [l]. 17 :3.5 SVX ladder. From [l]. . . . . . . . . . . . . . . . . 18 :3.6 \Yhen a charged particl~ passes through the VTX. the gas is ionized. The

freed electrons drift to the sense wires shown. From [l]. U)

:3.7 CTC endplate. From [l]. . . . . . . . . . . . . . 20 :3.8 . .\ 15° ,:J wcdgt? of the Central calorimeter. From [l].

-L l Orientation of the quartz fiber t:alorimeter prototypP 1luring tPstbea.m studies of the effects of radiatiun dama~P. The tower uumlwriu~ scheme used for these studies is shown. The direction of the beam used to irradiate tlw module ( LIL Beam) and the direction of the bl'am usPd to ,L,st>ss tht> effects

22

of irradiation on the calurimctt>r·s lH'rformancc (H-l Beam) arc shown. :33 -l.2 The average signal in Tower 5 recorded in =-scans with dectruus 1•nterin~

the detector in the regions y = 0 - 5 nun and !/ = 20 - :!5 mm. respectively. 3!)

-L3 Simulated re!-iponse curves based on Equation -l.-l and the dust> profile D(=) accumulated in the !I interval 0-;j mm for n = 0 and different \·,tlues of the parameter o. For comparison. the experimental .:-response curve fur !J = 0 - 5 mm. conveniently normalized. is shown a-; well. See text for details. -H

-L4 Simulated response curves based on Equation 4.-l au<l the dose prolil1~ D( =)

accumulated in the y interval 0-5 mm fur <liffereut values of the parameters n an<l rt. For compa:ison. the experimentally mi·:L·:urc<l curve is shown as

well. See text for details. . . . . . . . . . . . . . . . . . . . 42

.s.1

- ·) o._

5.3

5.4

The Plug Upgrade testbeam module consisted of four 15" sections. each with 20 towers. Wedge 3 was built w-ithout a.n E.\f section. . ....

The energy scale for the E.\f calorimeter section . .-\. as a function of energy.

The euer6ry sea.le of the ha.dronic section. BI· found using .\Iethod I a-; a function of the energy depo!-iited in the hadronic section of the calorimeter by penetrating pious. . . . . . . . . . . . . . . . . . . . . . . . . . . .

The energy scale of the hadronic section. B11. found using .\Iethod II as a function of the energy of the incoming electrons. . . . . . . . . . . . . .

The reconstructed energy of penetrating (top) and nonpenetrating (bottom) pious when Method I is used to find the value of B. . . . . . . . . . . .

IX

4,j

46

47

48

51

62

chr 4'j ±jK~?=/±^K/jW j?j±J° ~! %j?j/±_/X?J T/~%' _?W ?~?%j?j/±_/X?J T>~//~—' %X~?= ['j? -j/'~W vvv X= ^=jW /~ !X?W /'j ;_^j ~! o hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh

chp 4'j ±_/X~ ~! /'j ±jK~?=/±^K/jW j?j±J° _?W /'j Wj%~=X/jW j?j±J° _= _ !^?KE/X~? ~! /'j j?j±J° Wj%~=X/jW >° %X~?= ='~[j±X?J X? /'j g,B L^J 8%J±_Wj K_~±X—j/j±h 0j=^/= _±j JX;j? !~± /'j /'±jj K_X>±_/X~? —j/'~W= WX=K^==jW X? /'j /j]/h 4'j K^±;j= /'±~^J' /'j %~X?/= _±j !X/= /~ /'j !^K/X~? X? w*^_/X~?chahhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh

cht 4'j 7j/ j?j±J° ±j=%~?=j ~! /'j L^J 8%J±_Wj g_~±X—j/j± _= !~^?W ^=X?J /'j -~?/j g_±~ %±~J±_— Wj=K±X>jW X? /'j /j]/h 4'j =~%j ~! /'j X?j !X//X?J /'j ±j=%~?=j X= _±Jj± ['j? -j/'~W v X= ^=jW /'_? ['j? -j/'~W vvv X= ^=jW

chb 0_/X~ ~! /'j %_±/XKj j?j±J° ±jK ~?=/±^K/jW >° /'j K_~±X—j/j±h Dq7 h _?W /'j %_±/XKj —~—j?/^— —j_=^±jW [X/' /'j /±_K9X?J =°=/j—* • _= _ !^?K/X~? ~! • !~± X=~_/jW /±_K9= 'X//X?J /'j gj?/±_ K_~±X—j/j± X? /'j X??j± ncR ~! /'j /_±Jj/ /~[j± !_Kjh Zjj /j]/ !~± Wj/_X=hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh

chms 4'j *^_?/X/° bit ■ D*—RN0qN\•{ %~//jW ;= /'j —~—j?/^—h D■<—<]N0q< X= /'j /~/_ j?j±J° X? /'j t jjK/±~—_J?j/XK /~[j±= =^±±~^?WX?J /X?o /_±Jj/ /~[j± !~± /±_K9= ['XK' %j?j/±_/j /'j jjK/±~—_J?j/XK =jK/X~? [X/'~^/ X?/j±_K/X?Jh 4'X= *^_?/X/° X= _? j=/X—_/j !~± /'j _;j±_Jj j?j±J° Wj%~=X/jW X? /'j K_~±X—jE/j± >° ?j^/±_ %_±/XKj= _KK~—%_?°X?J K'_±JjW %_±/XKj= /'_/ %±~W^Kj J~Wj? /±_K9=hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh

chmm °D0R00\•{ ;= • !~± X=~_/jW /±_K9= 'X//X?J /'j gj?/±_ K_~±X—j/j± X? /'j X??j± nrR ~! /'j /_±Jj/ /~[j± !_Kjh D5£00 X= Wj!X?jW _= D5q< E D*NRN0q]» Zjj /j]/ !~± Wj/_X=hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh

chma 4'j j?j±J° X? /'j /_±Jj/ /~[j± ~! /'j jjK/±~—_J?j/XK =jK/X~? T/~%' _?W /'j j?j±J° X? /'j b '_W±~?XK /~[j±= >j'X?W /'j /_±Jj/ /~[j± T>~//~—'h Z'~[? _±j %_±/XKj= [X/' —~—j?/_ >j/[jj? c _?W mc kj1iKh Lj?j/±_/X?J %_±/XKj= _±j Wj!X?jW _= /'~=j !~± ['XK' /'j j?j±J° X? /'j /_±Jj/ jjK/±~—_J?j/XK /~[j± X= >j/[jj? shaEshc kj1 _?W /'j j?j±J° X? /'j b '_W±~?XK /~[j±= X= J±j_/j± /'_? mhs kj1Ah P♦~^%j?j/±_/X?J %_±/XKj= _±j /'~=j !~± ['XK' /'j j?j±J° X? /'j /_±Jj/ jjK/±~—_J?j/XK /~[j± X= J±j_/j± /'_? shp kj1hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh

hmn D5£00\• !~± %j?j/±_/X?J _?W ?~?%j?j/±_/X?J %X~?= ['j? -j/'~W v X= ^=jWh Z'~[? _±j %_±/XKj= [X/' —~—j?/_ >j/[jj? c _?W mc kj1iKh 4'j —j_?= ~! /'j WX=/±X>^/X~?= WX!!j± >° <maRh P~/j /'_/ —~=/ /±_K9= _±j X? /'j ?~?%j?j/±_/X?J K_/jJ~±°hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh

chmu 4'j !_K/~±* v®■ /'_/ /'j '_W±~?XK =jK/X~? j?j±J° —^=/ >j —^/X%XjW >° X? ~±Wj± /~ j*^_X\j D5£00\• !~± %j?j/±_/X?J _?W ?~?%j?j/±_/X?J %X~^=* v{ X= K~?=/_?/ ~;j± • hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh

]


5.6 The recoru;tructed energy of penetrating ( top) and nonpeuetrating (bottom) pions when Method III is used to find the value of B. . . . . . . . . . . 52

,J.1 The ratio of the recoustructed energy a.nd the deposited energy as a function of the energy deposited by pious showering in the CDF Plug Cpgrade calorimeter. Results are given for the three calibration methods discussed in the text. The curves through the points are fits to the fuction in Equation - ? ;), __

-5.8 The jet energy response of the Plug L"pgrade Calorimeter as found using the Monte Carlo program described in the text. The slope of the line fitting the response is larger when Method I is used than when :\[ethod III is used. 56

5.9 Ratio of the particle energy reconstructed by the calorimeter. Ee.LI· and the partide momentum measured with the tracking system. p as a function of p for isolated tracks hitting the Central calorimeter in the inner :.!6% of the target tower face. See text for details. . . . . . . . . . . .

5.10 The quantity ':J/8 · (EnrntradP) is plottP<l vs the momentum. Erieutral is the total energy in tliti 8 electrumaµ;netic towers surruuwliug the target tower fur tracks which penetratP the dectrumagnetic section without interacting. This quantity is an estimate fur the average energy deµosited in the caloriuuiter by rwutral part ides accompanying charged particles that produce golden

;j!)

tracks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

5.11 (Ecarr/ p) vs p for isolated tracks hitting the Central calorimeter in the inner :.!6% of the target tower face. Ecorr is defined a..-; Ecal - Enrntral· Sec text for details. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

-5.12 The energy in the target tower of the electromagnetic section (top) a.nd the energy in the 9 hadronic towers behind the target tower (bottom). Shown arc particles with momenta between 5 and 15 GeV/c. Penetrating particles are defined as those for which the energy in the target electromagnetic tower is between 0.2-0.5 GeV and the energy in the 9 hadronic towers is greater than 1.0 GeV. Nonpenetrating particles are those for which the ener1,1y in the target electromagnetic tower is greater than 0.7 GeV. . . . . . . . . . 63

5.13 Ecorr/P for penetrating and nonpenetrating pions when :\Iethod I is used. Shown are particles with momenta between 5 and 15 GeV /c. The means of the distributions <liffer by -12%. i:'i'ote that most tracks arc iu the nonpenetrating category. . . . . . . . . . . . . . . . . . . . . . . . . . . 65

5.1-l The factor, (k). that the hadronic section energy must be multiplied by in order to equalize Ecorr/P for penetrating and nonpenetra.ting pioru;. (k) is constant over p. 6G

X

chmc D5£00\• !~± %j?j/±_/X?J _?W ?~?%j?j/±_/X?J %X~?= ['j? -j/'~W vvv X= ^=jWh4'j %~/ ~?° X?K^Wj= %_±/XKj= [X/' —~—j?/_ >j/[jj? c _?W mc kj1iKh4'j —j_?= ~! /'j WX=/±X>^/X~?= _±j ?~/ =XJ?X!XK_?/° WX!!j±j?/ JX;j? /'j =/_E/X=/XK_ ^?Kj±/_X?/Xj=hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh rp

rhm 0j_/X;j X—%±~;j—j?/ ~! /'j 7j/ ±j=~^/X~? >° ^=X?J /'j w?j±J° B~[ -j/'~W*_= _ !^?K/X~? ~! /'j 7j / j?j±J°h 0j=^/= ~! -~?/j g_±~ =X—^_/X~?= [X/' WX!E!j±j?/ %_±_X?j/j±j K'~XKj= 4'j >_K9 WX_—~?W= [j±j ~>/_X?jW ^=X?J /j=/>j_— W_/_ !±~— /'j g,B L^J 8%J±_Wj K_~±X—j/j±h Zjj /j]/ !~± Wj/_X=h h h h pn

phm 4'j =XJ?_ v!A* ' $ — N 1 =jj? >° 8xah 4'j =XJ?_ ='~[? K~?=X=/= ~! cTXt„mnnu pZ

pha gj?/±_ K_~±X—j/j± =XJ?_ WX=/±X>^/X~?= ~>/_X?jW ^=X?J X=~_/jW /±_K9= !±~— 0^? vy —X?X—^— >X_= W_/_h ZXJ?_ WX=/±X>^/X~?= _±j ='~[? =j%_±_/j° !~± /'j jjK/±~—_J?j/XK _?W '_W±~?XK =jK/X~?= !~± /±_K9= [X/' —~—j?/_ X? /'jsEm kj1 iK ±_?Jj _?W mEa kj1iK ±_?Jjh Zjj /j]/ !~± Wj/_X=hhhhhhhhhhhhhhhhhhhhhhhhhhhhh tn

phn ZXJ?_ WX=/±X>^/X~?= !~± /'j Kj?/±_ jjK/±~—_J?j/XK K_~±X—j/j± _?W /'j Kj?E/±_ '_W±~?XK K_~±X—j/j±h ,X=/±X>^/X~?= [j±j ~>/_X?jW !±~— X=~_/jW /±_K9= X? 0^? vy —X?X—^— >X_= W_/_ _?W _±j ='~[? !~± '_W±~?= [X/' • f a E n kj1iK _?W • m n E u kj1iKh Zjj /j]/ !~± Wj/_X=hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh bc

X hu gj?/±_ jjK/±~—_J?j/XK _?W '_W±~?XK K_~±X—j/j± =XJ?_ WX=/±X>^/X~?= ~>E/_X?jW !±~— X=~_/jW /±_K9= X? 0^? vy —X?X—^— >X_= W_/_ [X/' • * u E c kj1 _?W • l c kj1iKh Zjj /j]/ !~± Wj/_X=hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh br

phc zj/ =XJ?_ WX=/±X>^/X~?= ['XK' ±j=^/ !±~— =X—^_/X~?= Wj=K±X>jW X? /j]/hqj±jh -j/'~W vvv [_= ^=jW /~ =j/ /'j j?j±J° =K_j ~! /'j Kj?/±_ '_W±~?XK K_~±X—j/j±h ,X=/±X>^/X~?= _±j ='~[? !~± 7j/ j?j±JXj= ±_?JX?J !±~— msEkQ kj1Ah bp

< hr zj/ ±j=%~?=j K^±;j= !~± g,BA= /±_WX/X~?_ —j/'~W ~! Wj/j±—X?X?J /'j j?j±J°=K_j ~! /'j '_W±~?XK K_~±X—j/j± =jK/X~? T-j/'~W v' _?W _ ?j[ —j/'~W ~! =j//X?J /'j '_W±~?XK =jK/X~? j?j±J° =K_j T-j/'~W vvv'h 4'j ±j=%~?=j X=?~±—_X\jW /~ /'_/ ~! jjK/±~?=h 4'j X?;j±=j ~! /'j ±j=%~?=j ±j%±j=j?/= /'j K~±±jK/X~? !_K/~± !~± /'j _>=~^/j 7j/ j?j±J° =K_j T=jj w*^_/X~? phms'h h h bt

< » [ 0_[ WX7j/ X?;_±X_?/ —_== =%jK/±^—h P~ j?j±J° K~±±jK/X~?= '_;j >jj? _%E%XjWh 4'j /[~ 7j/= [j±j ±j*^X±jW /~ >j >_K9E/~E>_K9 TK~= »vl d Es hu' _?W j;j?/= X? ['XK' _ /'X±W 7j/ [X/' D 6 l mc kj1 [_= %±j=j?/ [j±j ±j7jK/jWh4'j =/jj% !_~!! >j~[ cs kj1iK® X= _ ±j=^/ ~! /±XJJj± X?j!!XKXj?KXj=h h h h bb

pht 3^_X/° ~! j]%~?j?/X_ !X/= /~ /'j WX7j/ X?;_±X_?/ —_== =%jK/±^— ~;j± _ X—X/jW —_== ±_?Jjh Z'~[? X= /'j T!~± an WjJ±jj= ~! !±jjW~—' _= _ !^?K/X~? ~! /'j ~[j=/ —_== %~X?/ ~! /'j uc k j1 i/± [XWj WX7j/ —_== ±jJX~?h Zjj /j]/ !~± Wj/_X=hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh mss

]X


5.15 Ecorr/P for penetrating and nonpenetrating pions when Method III is used. The plot only includes particles with momenta between 5 and 15 GeV/c. The means of the distributions are not significantly different given the sta-tistical uncertainties. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

6.1 Relative improvement of the jct resolution by using the Energy Flow ~Ietho<l. as a function of the jet energy. Results of Monte Carlo simulations with differPnt parametere choices The black diamonds were obtained using testbeam data from the CDF Plug Upgrade calorimeter. See text fur details. 73

7.1 The signal W. Z ~ jet:; seen by C.-\2. The signal shown consists of 5618±1:J:J-t 78

7.2 Central calorimeter signal distributions obtained using isolatt~d tracks from Run IB minimum bias data. Signal distributions are shown separately for the electromagnetic and hadronic sections for tracks with momenta in the 0-1 GeV /c range and 1-2 GeV/c range. See text for details. . . . . . . . . 8:3

7.:3 Signal distributions for the central elt>ctromagnetic calorimeter awl the c1~ntral hadronic calorimeter. Distributions wew obtained from isolated tracks in Run IB minin11un bi,L-; data and are shown for hadrons with p = :? - :J Ge V / c and p = :J - -l Ge V / c. See text for details. . . . . . . . . . . . . . 95

7.-! Central electromagnetic and hadronic calorimeter signal distributions obtained from isolated tracks in Run IB minimum bias data with p = -I - -:i GeV and p > 5 GeV/c. See text for details. . . . . . . . . . . . . . 96

, .·J .Jet signal distril,utions which result from simulations described in text. Here. ~Iethod III was used to set the energy scale of the central hadronic calorimeter. Distributions are shuwn fur jet energies ranging from 10-GO Ge\'. 97

7.6 .Jet response curves for CD F's traditional method of determining the energy scale of the hadronic calorimeter section (Method I) and a new method of setting the hadronic section energy scale (Method III). The response is normalized to that of electrons. The inverse of the response represents the correction factor for the absolute jet energy scale (see Equation 7.10). 98

7. 7 Raw dijet invariant mass spectrum. N'o energy corrections have been applied. The two jets were required to be back-to-back ( cos •I> < -0.-1) a.nd events in which a third jet with ET > 15 GeV wa.s present were rejected. The steep falloff below 50 Ge V / c2 is a result of trigger inefficiencies. 99

7.8 Quality of exponential fits to the dijet invariant mass spectrum over a limited mass range. Shown is the ,'(:.! (for 2:3 degrees of freedom) as a function of the lowest mass point of the -15 GeV /c? wide dijet mass region. See text for details. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100

xi

phb 0j=XW^_= ['j? _? j]%~?j?/X_ >_K9J±~^?W X= =^>/±_K/jW !±~— /'j ±_[ WX7j/ —_== =%jK/±^— T_' _?W !±~— /'j WX7j/ —_== =%jK/±^— X? ['XK' 7j/= _±j K~±±jK/jW ^=X?J -j/'~W vvv T>'h 4'j X/ ='~[? X= /'j =^— ~! /[~ k_^==X_? WX=/±X>^/X~?= X? ['XK' /'j WX!!j±j?Kj >j/[jj? /'j /[~ —j_?= _?W /'j ±_/X~ ~! /'j [XW/'= ~! /'j /[~ J_^==X_?= [j±j !X]jW* > ^ / _ ~/'j± %_±_—j/j±= [j±jj!/ !±jjh Zjj /j]/ !~± Wj/_X=hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh msm

phms 0_[ WX7j/ —_== =%jK/±^—h Z'~[? X= _ !X/ /~ /'j =%jK/±^— X? /'j ±_?Jj macE nss k j1 iK; 4'j !X/ X= j]/±_%~_/jW /~ ~[j± ;_^j= ~! WX7j/ ??X== X? ~±Wj±/~ j]/±_K/ _ /±XJJj± j!!XKXj?K° ;= WX7j/ —_== K^±;jh Zjj /j]/ !~± Wj/_X=h h h msa

p hm m 4±XJJj± j!!XKXj?K° K^±;j ±j=^/X?J !±~— WX;XWX?J /'j ~±XJX?_ WX7j/ W_/_ T±_[' >° /'j j]/±_%~_/jW !X/ /~ /'j >_K9J±~^?W ±jJX~? macEnss kj2iK<h Z'~[?X= _ !X/ /~ /'j W_/_ [X/' /'j !^?K/X~? _±K/_?h Zjj /j]/ !~± Wj/_X= hhhhhhhhh msn

< hma 0j=^/X?J =XJ?_ ['j? /'j ~±XJX?_ W_/_ T±_[' X= WX;XWjW >° _ !X/ /~ /'j /±XJJj±j!!XKXj?K° K^±;j ='~[? X? BXJ^±j phmmhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh msu

< hmn 0j=^/X?J =XJ?_ ['j? /'j ®-j/'~W vvv WX7j/ —_== =%jK/±^—N X= WX;XWjW >°_ !X/ /~ /'j /±XJJj± j!!XKXj?K° K^±;jhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh msc


7.9 Residuals when an exponential background is subtracted from the raw dijet mass spectrum {a) and from the dijet mass spectrum in which jets are corrected using 1Iethod III (b). The fit shown is the sum of two Gaussian distributions in which the difference between the two means and the ratio of the widths uf the two gaussians were fixed. but all other parameters were left free. See text for details. . . . . . . . . . . . . . . . . . . . . . . . . 101

7.10 Raw dijet mass spectrum. Shown is a fit to the spectrum in the range 125-300 GeV/c?. The fit is extrapolated to lower "-.tlues of dijet mass in order to extract a trigger efficiency vs dijet mass curve. See text for details. 102

7 .11 Trigger efficiency curve resulting from dividing the original dijet data ( rmv) by the extrapolated tit to the background region 125-300 GeV/c~. Shown is a fit to the data with the function arctan. See text for details. 103

7.12 Resulting signal when the original data (raw) is divided by a tit to the trigger efficiency curve shown in Figure 7.11. . . . . . . . . . . . . . . . . 1()-1

7.1:3 Rl'Stdtiug signal when the ··~[ethod [I[ dijPt mass spt•ctmm .. is divided by a fit tu the trigger dficiem:y curw ..... . 105

xii

g q x L 4 w 0 m

vP 4 0 Q , 8 g 4 vQ P

L_±/XKj %'°=XK= X?;~;j= /'j = /^ W ° ~! /'j — ~=/ !^?W_— j? /_ K~?=/X/^j?/= ~ ! — _ / /j ±

_? W /'j X?/j±_K/X~?= >j/[jj? /' j— h x >±Xj! ±j;Xj[ ~ ! /'j Z /_ ? W _ ±W -~Wj ~ ! %_±/XKj=

_ ? W X?/j±_K/X~?= X= JX;j? X? g ' _ % /j ± ah w]%j±X— j?/_X= /= X? %_±/ XK j %'°=XK= ^=j '^Jj

%_±/XKj _KKjj±_/~±= /~ =%jjW %_±/ XK j= ^% /~ ;j±° 'XJ' j?j±JXj= T4 j1 m' _?W /' j ? !~±Kj

/'j— /~ K~XWjh 8=X?J _±Jj %_±/ XK j Wj/jK/~±=* /'j° /'j? — j_=^±j ;_±X~^= % ±~%j±/Xj=

~! /'j ±j=^/X?J %_±/ XK j Wj>±X=h g ' _ % /j ± n Wj=K±X>j= /'j %_±/XK j _KKjj±_/~± _ ? W ~?j

~! /'j %_±/XKj W j /jK /~ ±= Tg~XWj± ,j/jK/~± _/ Bj±—X_>' ^=jW _ / /'j Bj±—X P _/X~?_

xKKjj±_/~± ) _ > ~ ±_ /~ ±° TBj±— X_>'h

4 'j %_±/XKj Wj /jK /~ ±= ^=jW _ / %_±/XK j _KKjj±_/~±= _±j —^/X%^±%~=jU Wj /jK /~ ±= [X/'

— _?° /'~^=_?W= ~ ! jjK/±~?XK K'_??j= h v? /'X= /'j=X=* [j K~?Kj? /±_ /j ~? ~?j =^>=°=E

/j— ~! =^K' — ^ / X%^ ±%~=j Wj/jK /~ ±= * ?_—j° /'j K_~±X— j/j±=h g_~±X— j/j±= — j_=^±j

/'j j?j±J° ~! K'_±JjW _?W ?j^ /±_ %_±/XKj=h 4'j >_=XK [~±9X?J= ~! K_~±X— j/j±= _±j

Wj=K±X>jW X? g ' _ % /j ± uh Zj;j±_ = /^W Xj= X?;~;X?J K_~±X— j/j±= [j±j %j±!~±—jWh 4[~

A ~ ! /'j=j =/^WXj= [j±j X?Wj%j?Wj? /* =j!EK~?/_X?jW _?_°=j=* _?W /' j /'X±W = /^ W ° jW WXE

±jK/° /~ _? _?_°=X= ~! _ =_— %j ~ ! W _ /_ /_9j? [X/' /'j g~XWj± ,j/jK/~± _ / Bj±— X_>

Tg , B 'h

4 'j !X±=/ =j !EK~?/_X?jW _?_°=X= X?;~;jW _ = /^ W ° ~! ±_W X_ /X~? W_— _Jj X? _ % ±~ /~ E

/°%j >^X/ !~± /'j 1j±° B~±[_±W g _~±X— j/j± ~! /'j g ~— %_K/ - ^~? Z~j?~XW Tg- Z'

W j /jK /~ ± _/ /'j !^ /^ ±j % ±~ /~? E% ±~ /~? K~XWj±* /'j )_±Jj q _W±~? g~XWj± T)q g 'h v?

/' X= =/^W°* /'j % ±~ /~ /° % j [_= X ± ±_ W X_ /j W [X/' %_±/XKj= ~! /'j /°%j ±j=%~?=X>j !~± ;j±°

_±Jj ±_WX_/X~? W~=j= ['XK' _±j j]%jK /jW /~ _KK^— ^_ /j X? /'j !~±[_±W K_ ~±X— j/j±=

W^ ± X?J % ±~ /~?E%±~ /~? K~X=X~?= _ / /'j )qgh x!/j± /' j X±±_W X_ /X~? * /'j %j±!~±— _?Kj

FF dks9 FO#*ks; F ks 9 FO« F‘ _^£>k

m


CH.-\PTER 1

I.\'.TRODCCTIO.\'.

Particle physics involves the study of the most fundamental constituents of matter

and the interactions between them .. -\ brief review of the Standard .\lode! of particles

and interactions is given in Chapter 2. Experimentalists in particle physics use huge

partide accelerators to speed particles up to very high energies (Te\· 1} and then force

them to collidt•. Csing large particl1• d£'trctnrs. tlwy then measure various properties

of the mmlting pa.rtide debris. Chapter :3 describes the particle accelerator and one

of the particle detectors (CollitlPr Detector at Fermilab) used at the FL•rn1i :'\ational

.-\ccelerator Laboratory ( FPnnilab).

ThP partidP dl1 tl1ctors used at particle ,HTP!l'raturs an• multipurposP d1•t1•ctors with

many thousands of electronic channels. In this tlwsis. we concentratl' on one subsys

tem of such multipurpose detPctors. nanll'ly tht• calorimeters. Calurinll'tt•rs rm•;.L-;urP

the n1ergy of charged and neutral particles. ThP basic workings of calorimeters are

described in Chapter -L Several studies involving calorimeters were performed. Two

' of these studies were independent. self-contained analyses. and the third study led di

rectly to an analysis of a sample of dc1.t,1. taken with the Colli<ler Detector at Fermilab

(CDF).

The first self-contained analysis involved a study of radiation damage in a proto

type built for the \"ery Forward Calorimeter of the Compact ~Iuon Solenoid (C:\IS)

detector at the future proton-proton collider. the Large Hadron Collider (LHC). In

this study. the prototype wa.s irradiated with particles of the type responsible for very

large radiation doses which are expected to accumulate in the forward calorimeters

during proton-proton collisions at the LHC .. -\fter the irradiation. the performance

11 TeV= 101:!eV: l eV = 10-w joule

1

~! /'j K_ ~ ±X— j/j± [_= /j=/jW _?W _ —~Wj [_= Wj;j~%jW /~ Wj=K±X>j /'j j!!jK/= ~!

±_W X_ /X~? W_— _Jjh 4' X= [~±9 X= Wj=K±X>jW X? Wj/_X X? ZjK/X~? uhp _ ? W x%%j?WX] xh

4 'j =jK~?W = /^ W ° X?;~;jW /'j j;_^_/X~? ~! _? _ J~±X/'— ^=jW /~ Wj!X?j /'j j?j±J°

~ ! _ 7j / h =%±_°= ~! %_±/XKj= ±j=^/X?J !±~— /'j > ±j_9^% ~! _ '_W ±~? T=^K' _= _ %±~ /~?'h

g _ X— = '_;j ±jKj?/° >jj? — _Wj X? /'j X /j ±_ /^ ±j /' _ / /'j ^=j ~! /' X= _J~±X/'— _~?J

[X/' _ 'XJ'° =jJ— j?/jW K_~±X— j/j± [~^W ±j=^/ X? !_?/_=/XK X—%±~;j—j?/= X? /'j

j?j±J° — j_=^±j— j?/= ~! 7j/= h 6j '_;j %j±!~±—jW = X— ^_/X~?= ['XK' ='~[ /' _ / /'j

X— %±~;j— j?/ X= ~! /'j ~±Wj± ~! nsRh > ^ / /'_/ =jJ— j?/_/X~? W~j= ?~/ %_° _ ±~j X?

/'j X— %±~;j— j?/h x/ 'XJ'j± 7j / j?j±JXj=* /'j X—%±~;j—j?/ %±~;XWjW >° /'j _ J~±X/'—

WjK±j_=j=* _ ? W /'j j?j±J° ±j=~^/X~? ~! /'j K_~±X— j/j± !~± '_W±~?= >jK~—j= /'j W ~ — E

X?_?/ !_K/~± X? /'j j?j±J° — j_=^±j— j?/ ~! 7j/=h 4'X= [~±9 X= Wj=K±X>jW X? Wj/_X X?

ZjK/X~? rhu _? W x %%j?WX] gh

4 'j = /^W° ['XK' jW /~ _? _?_°=X= ~! g, B W _ /_ X?;~;jW /' j K_X>±_/X~? ~! _

K_ ~ ±X— j/j± ['XK' X= =jJ—j?/jW X?/~ /[~ %_±/= _~?J /'j W X±jK/X~? ~! X?K~—X?J % _ ± / X E

Kj=h _? j jK /±~— _J?j/XK =jK/X~? _?W _ '_W±~?XK =jK/X~? T=jJ— j?/_ /X~? X= WX=K^==jW X?

ZjK/X~? uhu'h 6 'j? _ K_~±X— j/j± X= =jJ— j?/jW X? /'X= [_° _?W ['j? X/ X= ?~?K~—%j?E

=_ / X? J T/'j =XJ?_ ±j=^/X?J !±~— _ cs k j1 K'_±JjW %X~? X= =— _j± /' _ ? /' _ / !±~— _ cs

k j1 jjK/±~?o =jj ZjK/X~? uhrhu'h K_ X> ±_ /X?J /'j Wj/jK /~ ± X= ?~?/±X; X_ h 6j Wj;j~%jW

_ ?j[ — j/'~W /~ K_ X> ±_ /j =^K' _ K_~±X— j/j±* _?W /'X= — j/'~W j X— X?_/j= %±~>j—=

[X/' %±j;X~^=° ^=jW — j/'~W=h 4'X= = /^ W ° X= Wj=K±X>jW X? Wj/_ X X? g'_%/j± c _ ? W

x %%j?W X] yh 6j _%%XjW /'X= ?j[ — j/' ~ W /~ _ =_— %j ~! W _ /_ /_9j? [X/' /'j g , B

Wj /jK /~ ± * ?_— j° _ =_— %j ~! < n —XX~? j;j?/= [X/' /[~ 7j /= X? /'j j;j?/h v? /' X=

=_— %j ~! W _ /_ * [j ~~9jW !~± /[~E7j/ WjK_°= ~! /'j vB _?W ' >~=~?= T—jWX_/~±= ~ !

/' j [j_9 !~±Kje =jj g ' _ % /j ± a' X? /'j W X7j / X?;_±X_?/ —_== =%jK /±^— h 8=X?J /'X= W _ /_

=_— %j * j;j?/= ~! /'X= /°%j K_??~/ >j !~^?W ~? _? j;j?/E>°Ej;j?/ >_=X=* =X?Kj /'j°

% ±~W^Kj _ =XJ?_ X? /'j Wj /jK /~ ± T/[~ 7j /=' ;j±° =X— X_± /~ /' _ / % ±~W^KjW >° /'j _±Jj

>_K9J±~^?W !±~— % _ ±/~ ? E% _ ± /~ ? =K_//j±X?J h 4'j=j j;j?/= K_? >j !~^?W* '~[j;j±* X? _

©l


of the calorimeter was tested and a model was developed to describe the effeds of

radiation damage. This work is described in detail in Section -L 7 and . ..\ppendix .-\.

The second study invoked the evaluation of an algorithm used to define the energy

of a jet. sprays of particles resulting from the breakup of a hadron (such as a proton).

Claims have recently been made in the literature that the use of this algorithm along

with a highly segmented calorimeter would result in fantastic improvements in the

energy measurements of jets. \\'e have performed simulations which show that the

impron'ment is of tlH' order of :30'7c. but that segmentation does not play a role in

the improvement. .-\t higher jet ent'rgies. the impro,;ement provided by tht• algorithm

decreases. and the energy resolution of tht> calurimeu•r for hadrons becomes tlw dom

inant factor in the Ptwrgy nu•,burement of jt•ts. This work is dPscriht•d in cktail in

Section 6.-l and Appendix C.

Tln~ study which lt>d to an analysis of CDF data im·olved the calibration of a

calorimeter whid1 is segmP11ted into two parts along tht• direction uf incoming parti

cles. an t>lt!ctrumagnetic Sl'ction and a hadronic section (sPgmentation is discussed in

Section -l.-l). \\"hen a calorimeter is segrnentl•d in this way and when it is noncompen-

• sating (the signal resulting from a 50 Ge\· charged pion is smaller than that from a 50

Ge\" electron; see Section -L6.-l). calibrating the detector is nontrivial. \\"e dewloped

a new method to calihrate such a calorimeter. an<l this Plethod eliminates problerP'

with previously used methods. This study is described in detail in Chapter 5 and

. ..\ppendix B. \\'e applied this new method to a sample of data taken with the CDF

detector, namely a sample of ,.._..,3 million events with two jets in the event. In this

sample of data. we looke<l for two-jet decays of the tr and Z bosons (mediators of

the weak force; see Chapter 2) in the clijet invariant mass spectrum. Csing this data

sample. events of this type cannot be found on an event-by-event b,l..':iis. since they

produce a signal in the detector ( two jets) very similar to that produced by the large

background from parton-parton scattering. These events can be found. however. in a

2

= /_ /X= /XK_ — _??j± = X?Kj /'j >_K9J±~^?W T% _ ± /~ ? E% _ ± /~ ? =K_//j±X?J' X= _ =— ~~ /' !^?KE

/X~? ~! /' j W X7j / X?;_±X_? / —_==h 6 'j? /'j ?j[ K_ X> ±_ /X~? — j/'~W !~± /'j K_ ~ ± X— j/j ±

[_= ^=jWh btpn „ n b c s T=° = '„ mnsT=/_/' /[~E7j/ WjK_°= ~ ! /'j f _ ? W ' [j±j !~^?Wh

4'X= _?_°=X= X= Wj=K±X>jW X? Wj/_X X? g ' _ % /j ± ph 4 ' X= =XJ?_ X= _? X— % ~ ± /_ ? / K'jK9

~! /'j K_ X> ±_ / X~? ~ ! /' j 7j / j?j±J° _ / g , B h 4'j ^?Kj±/_ X? /° ~? /' j 7j / j?j ±J° X=

X— %~±/_? / !~± —_?° — j_=^±j— j?/= _/ g , B * jhJhh /'j /~% *^_±9 — _== — j_=^±j— j?/h


statistical manner since the background (parton-parton scattering) is a smooth func

tion of the dijet invariant ma::;s. \\"hen the new c.:alibration method for the c.:alorimeter

wa.-; used. 9873 ± 3950(sys)±l 130(stat) two-jet decays of the H. and Z were found.

This analysis is described in detail in Chapter 7. This signal is an important check

of the calibration of the jet energy at CD F. The uncertainty on the jet energy is

important for many measurements at CDF. e.g .. the top quark mass measurement.

3

g q x L 4 w 0 a

4 q w Z4x P, x0, - Q , w )

e[N 1>£R]% 9— •£11<9]— N£ —€•]q<* N>— ]q^1 £ : •>61<51 N£ q 9q0Sq<%B e Ex >j±/ w X?=/j X?

ahm v? /±~W^K/X~?

4 ' j K^±±j?/° _KKj% /jW /'j~±° ~! /'j !^?W_— j? /_ K~?=/X/^j?/= ~ ! — _ //j ± _?W

'~[ /'j° X?/j±_K/ X= K_jW /'j Z /_ ? W _ ±W -~Wj ~ ! L_±/XK j= _?W v?/j±_K/X~?=h v? /'j

Z /_ ? W _ ±W -~Wj* /'j ±j _±j !~^± !~±Kj=* /'j j jK /±~— _J?j/XK !~±Kj* /'j = /±~ ? J !~±Kj* /'j

[j_9 !~±Kj* _?W J ±_; X /° hm 4'j !^?W_— j?/_ %_±/XKj= _±j WX;XWjW X?/~ /' ±j j K_/jJ~±Xj=*

j%/~?=h *^_±9=* _?W J_^Jj >~=~?=h )j%/~?= !jj ~? ° /'j jjK/±~— _J?j/XK * [j_9 _?W

J ±_; X /_ / X~?_ !~±Kj=h 3 ^_±9= !jj _ !~±Kj=h k _^Jj >~=~?= K_±±° /'j !~±Kj= _?W _±j

±j!j±±jW /~ _= — jW X_ /~ ±= ~! /'j !~±Kj=h

4 ' j ±j _±j =X] j%/~?=h 4'j j jK/±~? Tj'h — ^~? °•{ _?W /_^ °0{ _±j j%/~?= ['XK'

K_±±° jjK/±XK K'_±Jj ~ ! Emh 4'j j jK/±~? °R—{B — ^~? °R,{ _? W /_^ °R"{ ?j^ /± X?~= '_;j

\j±~ jjK/±XK K'_±Jjh 4 ' j —~=/ ±jKj?/ j]%j±X— j?/_ j;XWj?Kj =^JJj=/= /' _ / /'j —_==

~! ?j^/±X?~=* ['Xj =— _* X= ?~/ \j±~h

4 ' j ±j _±j =X] /°%j= ~! *^_±9=* ^% Tii'* W~[? °%{B K'_±— TK'* = /±_?Jj °1{B >~//~—

°9{B _ ? W /~% °N{B 4 'j° j_K' K_±±° ’m in ’ jjK/±XK K'_±Jjh 4 'j° _=~ K_±±° _ K~~± K'_±Jj

T /'j K'_±Jj ~! /'j = /±~ ? J X? /j±_K/X~?' ~! ±jWh J±jj? ~± >^jh

4 ' j J_^Jj >~=~?= _ ±j /'j K_±±Xj±= ~! /'j !~^± !~±Kj=h 4 'j jjK/±~— _J?j/XK !~±Kj

X= — jW X_ /jW >° /'j — _==j== %'~/~?* /'j = /±~?J !~±Kj >° /'j —_==j== J^~?* _?W /'j

[j_9 !~±Kj >° /'j — _==X;j v4U _?W H “ %_±/XKj=h

)j%/~?= _?W *^_±9= _±j !j±—X~?= =X?Kj /'j° K_ ± ±° '_ ! X?/jJj± =%X? _ ? W ~>j° Bj±—XE

, X±_K =/_ / X= / XK= h k _^Jj >~=~?= _±j K_jW >~=~?= >jK_^=j /'j° '_;j X? /jJ±_ =%X? _?W

k ±_;X/° '_= ?~/ >jj? =^KKj==!^° X?K~±%~±_/jW X?/~ /'j Z/_?W_±W -~Wjh

u


CHAPTER 2

THE STA:'\0.-\RD ~IODEL

. ··ft should be possible to explain the law.s of phy.sic:.s to a barmaid. •· -.-\lbert Einstein

2.1 Introduction

The currently accepted theory of the fundamental constituents of matter and

how they intPract is called the Standard '.\[ode! of Particles and Interactions. In the

Standard '.\Ioele!. there are four forces. the electromagnetic forn'. the strong force. the

weak force. and gravity. 1 Till' fundamental particles an• dividnl into three categories.

leptons. quarks. and gauge bosons. Leptons ft•el only the Pit-ctruma.~m·tic. wPak and

gra\·itational forn•s. Quarks fr•el all furces. Gaugt> bosons earn· the forn~s and an•

n{errPd to as mediators of the forces.

There are six leptons. The electron (t}, muon (p) and tau(,) are leptons which

carry electril' d1arge of -1. The dectron (ve). muon (vµ) and tau (vr) neutrinos have

zero P!ectric charge. The most n•cf•nt experimrntal P\·idence suggests that the mass

of neutrinos. whilP small. is nut zero.

There a.re six types uf quarks. up {IL), down (d). cha.rm (c), strange (s). bottom

(b), and top (t). They each carry j 1/31 electric charge. They also carry a color charge

(the charge of the strong interaction) of red, green or blue.

The gauge bosons are the carriers of the four forces. The electromagnetic: force

is mediated by the massless photon. the strong force by the massless gluon. and the

weak force by the massive H·::: and zo particles.

Leptons and quarks are fprrnions since they carry half integer spin and obey Fermi

Dirac statistics. Gauge bosons are called bosons because they have integral spin an<l

1Gravity hcl.j not been successfully incorporated into the Standard Model.

-1

~>j° y~=jEwX?=/jX? =/_/X=/XK=h

w_K' !j±— X~? X? /'j = /_ ? W _ ±W —~Wj '_= _? _? /X%_ ±/ XK j ['XK' X= XWj?/XK_ /~ X/=

%_±/XKj X? /j ±— = ~! —_== _?W =%X? * >^/ '_= ~%%~=X/j ;_^j= !~± ~ /'j± %±~%j±/Xj= =^K'

_= jjK/±XK K'_±Jj ~± K~~±h

4 'j Z /_ ? W _ ±W -~Wj ^=j= J_^Jj /'j~±Xj= /~ — _/' j— _ /XK_ ° Wj=K±X>j '~[ !~±Kj=

X? /j ±_K / [X/' !^?W_— j?/_ %_±/XKj=h k _^Jj /'j~±Xj= _±j * ^ _ ? /^ — !XjW /'j~±Xj= X?

['XK' _? X?;_±X_?Kj %±X?KX%j ±j*^X±j= /'j j]X=/j?Kj ~! X? /j ±_K / X~?= _— ~?J /'j %_±E

/XKj=h 4'j J _^Jj /'j~±° ~! j jK /±~— _J?j/X=— * ['XK' ^=j= /'j 8 T ' J±~^%* X= K_jW

3 ^ _? /^ — wjK/±~W°?_— XK= T3 w , 'h 4'j J_^Jj /'j~±° !~± /' j = /±~?J !~±Kj* ['XK' ^=j=

/'j Zv4Tn' J ±~^% * X= K_jW 3 ^ _ ? /^ — g'±~— ~W°?_— XK= T3 g , ' _? W X= — ~WjjW _!/j±

3 w , h 4'j [j_9 X?/j±_K/X~? ^=j= /'j Z8TAa' J±~^%h 4'j J_^Jj /'j~±Xj= ~! /' j jjK/±~E

— _J?j/XK _?W [j_9 !~±Kj= '_;j >jj? ^?X!XjW T ) A T ' Z Z ATa '' X? /~ _ =X?Jj J_^Jj /'j~±°

K_jW /'j wjK/±~[ j_9 /'j~±°h

ahmhm 3 ^ _ ? /^ — wjK/±~W°?_— XK=

3 ^_? /^— wjK/±~W°?_— XK= K~??jK/= * ^ _ ? /^ — —jK'_?XK= /~ /'j K_==XK_ %±X?KX%j=

~ ! jjK/±XKX/° _ ? W —_J?j/X=— h v? 3 w , h /'j !~±Kj >j/[jj? /[~ K'_±JjW %_±/XKj= ±j=^/=

!±~— /'j j]K'_?Jj ~! _ !XjW * ^ _ ? /^ — * /'j %'~ /~? h

4 'j = /±j ? J /' ~! /'j jjK/±~— _J?j/XK X? /j ±_K /X~? X= JX;j? >° /'j jjK/±~—_J?j/XK

K~^%X?J K ~ ? = /_? / _ * JX;j? >°

* s x ° Zd {

['j±j — X= /' j jjK/±~— _J?j/XK K'_±Jj _?W _ X= /'j !X?j = / ±^ K /^ ±j K~?/_?/h 3w,

%±~Kj==j= _±j K _ K^ _ /jW ^=X?J _ % j ± /^ ±>_ / X;j j]%_?=X~? X? _ h 4 ' j ~[j=/ ~±Wj± %±~Kj==

T /j ±— = X? /'j % j ± /^ ±> _ / X~ ? j]%_?=X~? ['XK' _±j X?j_± X? _ ' * K_jW _ /±jj j;j %±~Kj==*

X= = X— %j /~ K_ K^ _ /j * >^/ 'XJ'j±E~±Wj± %±~Kj==j= T /j±— = X? /' j % j ± /^ ±> _ / X~ ? j]%_?=X~?

/' _ / _ ±j *^ _ W ±_ / XK ~± 'XJ'j± X? _ ' X?;~;j WX;j±Jj?/ TXhjh* X?!X?X/j' — ~— j?/^— X?/jJ±_=h

c


obey Bose-Einstein statistics.

Each fermion in the standard model has an antiparticle which is identical to its

particle in terms of mass and spin, but h~ opposite values for other properties such

as electric charge or color.

The Standard :\lode! uses gauge theories to mathematically describe how forces

interact with fundamental particles. Gauge theories are quantum field theories in

which an invariance principle requires the existence of interactions among the par

ticles. The gauge theory of electromagnetism. which uses the C( 1) group. is called

Quantum Electrodynamics (QED). The gauge theory for the strong force. which USPS

the SC{:3) group. is calkd Quantum Chromodynamics (QCD) and is modeled after

QED. The W<'ak interaction uses the SC(:2) group. The ga.uge theories of the l'lectro

rnagnetic and weak fot-cPs have been unified ( C( 1) 3 SC(:2)) into a single gauge theory

called the Ekct roweak theory.

2. l. l Quantum Electrodvnamics

Quantum Electrodynamics connects quantum mechanics to the classical principles

of electricity and magnetism. In QED. the force between two charged particles results

from the exchange of a field quantum, the photon.

Tltt-' strength of the electromagnetic interaction 1s given by the electromagnetic

coupling constant o, given by

•J e-o = - (2.1)

4.-r

where e is the electromagnetic charge and a 1s the fine structure contant. QED

processes are calculated using a perturba.tive expansion in o. The lowest order process

(terms in the perturbation expansion which are linear inn), called a tree level process,

is simple to calculate, but higher-order processes (terms in the perturbation expansion

that are quadratic or higher in o) involve divergent (i.e., infinite) momentum integrals.

5

x ±jWj!X?X/X~? ~± ±j?~±— _X\_ /X~? ~ ! /'j jjK/±XK K'_±Jj _=

U»Ul E ± ± Y > J e daEaA

['j±j - X= =*^_±j ±~~/ ~! /'j — ~— j?/^— /±_?=!j ± _?W , X= —_== ±j—~;j= /'j=j

X?!X?X/Xj=h 4'j - j Wj%j?Wj?Kj ~ ! /' j = /±j?J/' ~ ! /'j X? /j±_K /X~? —j_?= /' _ / _ / ' XJ'j±

j?j±J° =K_j=* /'j = /±j ? J /' ~! /' j jjK/±~— _J?j/XK X? /j±_K /X~? X?K±j_=j=h 4 ' j ;_^j

~! /' j !X?j = /±^ K /^ ±j K~?=/_? / X= ~!/j? *^~/jW _= mimnph >^ / /' X= X= ~?° /' j ;_^j _ /

_ /~ — XK j?j±J° =K_j=h x/ j?j±J° =K_j= j*^X;_j?/ /~ /'j — _== j?j±J° ~! /'j ' J_^Jj

>~=~? * /'j ;_^j ~! _ X= mimath 4 ' X= X= /j±—jW /'j N±^??X?JN ~ ! /'j K~^%X?J K~?= /_? /

_ ? W X= %'°=XK_° X? /j ±% ±j /jW _= _ =K±jj?X?J ~! /'j jjK/±XK K'_±Jj >° ;X±/^_ —H—H %_X±=

X? /' j ;_K^^—h

ahmha 3 ^_? /^— g '±~ /?~W°?_— XK=

3 g , X= /'j !~±—_ /'j~±° ~! /'j = /±~?J X? /j±_K/X~? >j/[jj? *^_±9= ['XK' X= >_=jW

~? /'j Z)♦Tn' = ° — — j /±° J±~^%h 4 'j ±j _±j t —_==j== J_^Jj >~=~?=* K_jW J^~?=*

['XK' ±j=^/ !±~— X— %~=X?J ~K_ J_^Jj X?;_±X_?Kjh k^~?= K_ ±±° _ * ^ _ ? /^ — K_jW

5£]£0 5>q04— ~± = X— %° 5£]£0B Q?° *^_±9= _?W J^~?= '_;j K~~± K'_±Jj* =~ /' j = /±~?J

!~±Kj _K/= ~?° ~? /'j— h 3 ^_±9= K_±±° _ K~~± K'_±Jj T±jWh J±jj?* ~± >^j' _?W

_ ? / X* ^ _ ±9 = K_±±° _ K~±±j=%~?WX?J _? /XK~ ~ ± K'_±Jj T_? /X±jW h _? /XJ±jj? * _?/hX>^%'h 4 ' j°

_±j 'jW /~Jj/'j± >° /'j j]K'_?Jj ~! J^~?=* ['XK' K_±±° ~?j K~~± K'_±Jj _ ? W ~?j

_? /XK~ ~ ± K'_±Jjh 3 g , X= _ J_^Jj X?;_±X_?/ !XjW /'j~±°* 7^ = / X9j 3w,h >^ / ^?X9j

3 w , * X/ X= *£**}9—]<q*■ — j_?X?J /' j Jj?j±_/~±= ~ ! /'j Z8Tn' J ±~^% W~ ?~/ K~— — ^/j h

4 ' X= %'°=XK_° — j_?= /' _ / /'j J ^~?= K_±±° K~~± K'_±Jj _?W K_? X?/j±_K/ [ X/' ~ /' j ±

J^~?=h 4'X= X= X? =' _ ±% K~?/±_=/ /~ 3 w , T/'j 8 T ' J±~^% X= _>jX_?'* ['j±j /'j

% ' ~ /~ ? X= jjK/±XK_° ?j^/±_ _?W W~j= ?~/ X? /j ±_K / [X/' X/=j!* ~?° [X/' %_±/XKj=

['XK' K_±±° jjK/±XK K'_±Jjh 4'X= 'X/= X?/j±j=/X?J K~?=j*^j?Kj= ['XK' _±j WX=K^==jW X?

!^ ± /' j ± Wj/_X X? ZjK/X~? rhmh

V


.-\ redefinition or renormalization of the electric charge as

•)

•) 'Q'') e-e- ( - -+ ------R. ·l-C 21~ e n -.\/~

(2.2)

where Q is square root of the momentum transfer and .\I is mass removes these

infinities. The Q2 dependence of the strength of the interaction means that at higher

energy scales. the strength of the electromagnetic interaction increases. The value

of the fine structurP constant is often quoted ~ 1/137. but this is only the value at

atomic erH'rgy scalr-s . .-\t ent>rgy scales equi\·,dent to the m~s energy of the Z gauge

boson. the value of n is 1/128. This is termed the --running'· of the coupling constant

and is physically interpr11ted as a screening of the Plt~t:tric charge by virtual ,,- t'- pairs

in t hP \·ac1111m.

2.1.2 Quantum Chromodvnamics

QCD is thP formal theory of tlH· strung interaction brtwl'en quarks which is based

on the SL"(:3) symmetry group. There are 8 m~sless gauge bosons. called gluons.

which result from imposing local gauge invariance. Gluons carry a quantum called

color charge or simply color. Only quarks and gluons han~ color charg1•. so the strong

furn' acts only on them. Quarks carry a color charge (red. gn'en. or blue) and

antiquarks rnrry a corresponding anticolor d1argf' (antired, antigref'n. antibli1P). They

are held together by the exchange of gluons, which carry one color charge and one

anticolor charge. QCD is a gauge invariant field theory. just like QED, but unlike

QED, it is rwn-Abelian. meaning the generators of the SC'(3) group do not commute.

This physically means that the gluons carry color charge and can interact with other

gluons. This is in sharp contrast to QED (the C(l) group is abelian). where the

photon is electrically neutral and does not interact with itself. only \vith particles

which carry electric charge. This has interesting consequences .,.,·hich a.re discussed in

further detail in Section 6.1.

6

ahmhn wjK/±~[j_9

4 ' j j jK /±~— _J?j/XK _?W [j_9 X? /j ±_K /X~?= [j±j ^?X!XjW X? /'j mbrs= >° k _='~[ h

Z _ _— _? W 6 jX?>j±J X?/~ _ =X?Jj J_^Jj /'j~ ±° K_jW /'j w jK/±~[ j_9 /'j~±°h 4'j

Z8 Ta' ] m Tm ' J_^Jj /'j~±° !~ ±— ^ _ /jW >° k _='~[ X?;~;jW !~^± —_==j== ;jK/~±

>~=~?=* /[~ ~! ['XK' _±j K'_±JjW* > ^ / ?~ —_==j==h K'_±JjW !Xj WE— jWX_/X?J %_±/ XK j=

'_W j;j± >jj? ~>=j±;jWh v? mbrph Z _ _ — _?W 6 jX?>j±J _%% XjW /'j qXJJ= — jK'_?X=—

/~ k _='~[ A= /'j~±°* ['XK' /' ±~ ^ J ' =%~? /_?j~^= =°— — j/±° E> ±j_9 X? J JX;j= /' ±j j ~!

/'j !~^± J_^Jj >~=~?= —_==h 4 ' j —_==j= ~! /' j jjK/±~[j_9 J_^Jj >~=~?=* /' j 8 ♦E

_? W ' F [j±j %±jW XK/jW >° /'j /' j ~ ±° _?X [j±j WX=K~;j±jW X? mbtn _/ /'j g w 0 5 ••

K~XWj±h 4 'j qXJJ= —jK'_?X=— ±j*^X±j= /'j %±j=j?Kj ~! ~?j — ~±j >~=~?* /'j qXJJ=

>~=~?h 4 'j —_== ~! /'j qXJJ= >~=~? X= _ !±jj % _ ±_ — j /j ± _?W K _ ? ~?° >j Wj /j ±— X?jW

j]%j±X— j?/_° h 4 'j qXJJ= >~=~? = / X j^Wj= j]%j±X— j? /_ X= /= _ ? W X= ~?j ~! /'j — ~=/

X— % ~ ± /_ ? / ~ ^ /= /_? W X? J X==^j= X? % _ ± / XK j %'°=XK= /~W_°h


2.1.3 Electroweak

The electromagnetic and weak interactions were unified in the 1960s by Glashow.

Salam an<l \Veinberg into a single gauge theory called the Electroweak theory. The

SC(2) x C(l) gauge theory formulated by Glashow involved four massless vector

bosons, two of which are charged. but no massless, charged field-mediating particles

had ever been observed. In 196,. Salam and \\"einberg applied the Higgs mechanism

to Glashow·s theory. which through spontaneous symmetry-breaking gives three of

the four gauge bosons mass. The rnassPs of the electroweak gauge bosons. thP 11 ·=

and zo were predicted by the theory and were discovered in 198:3 at tlw CER.\" pp

collider. The Higgs mP.chanism requires the presence of one more boson. the Hi~gs

boson. Tht> mass of thP Hiµ;gs boson is a free paranwter and can only be dPterrniru~d

t~xperimentally. The Higgs boson still eludes experimentalists and is ont! of tht1 must

important ontstanding issuPs in particle physics today.

g q x L 4 w 0 n

w 5 Lw 0 v- w P 4 x ) x L Lx 0 x 4 8 Z

6j >±Xj!° Wj=K±X>j /'j %_±/XKj _KKjj±_/~± _ ? W /'j %_±/ XK j Wj /jK /~ ± ^=jW /~ /_9j

/'j W _ / _ ^=jW X? /'j _?_°=X= Wj=K±X>jW X? g ' _ % /j ± ph 4 'j=j W _ /_ [j±j /_9j? W ^ ±E

X?J _ %j±X~W ~ ! _KKj j±_ /~ ± ~ %j ±_ / X~? K~X?jW N0 ^? vN ['XK' _=/jW !±~— mbtcEmbbrh

g ^±±j? /° h N0 ^? vv£ X= ^?Wj±[_° X? ['XK' — _?° X— %±~;j— j?/= [j±j — _Wj >~ /' /~

/'j _KKjj±_ /~± _? W /' j Wj/jK/~±h Q ?j ~! /'j Wj /jK /~ ± X— %±~;j— j?/= X= WX=K^==jW X?

ZjK/X~?= chm _ ? W chah

nhm 4 ' j L_±/XKj xKKjj±_/~±

4 ' j %_±/XKj _KKj j±_ /~ ± ['XK' %±~;XWjW /'j % ±~ /~ ? E_? /X% ±~ /~ ? K~X=X~?= !~± /'j

_?_°=X= Wj=K±X>jW X? g ' _ % /j ± p X= ~K_/jW _/ Bj±—X P_/X~?_ xKKjj±_/~± )_>~±_ /~ ±°

X? y _/_; X_ h vX?~X=h 4 ' j _KKjj±_/~± K~—%j]* ['XK' K~?=X=/= ~ ! =j;j±_ WX!!j±j?/ _KKjE

j ±_ /~ ±= K~??jK/jW X? =j*^j?Kj* X= ='~[? X? B XJ^±j nhmh B~± % ±~ /~?= * /'j _KKjj±_/X~?

=j*^j?Kj X=e Tm' g~K9K±~!/E6 _/~?h Ta' )X?_Kh Tn' y~~=/j±h Tu' -_X? 0X?Jh Tc' 4j;_E

/±~? h B~± _? /X% ±~ /~?= * /'j =j*^j?Kj X=e Tm' ,j>^?K'j±h Ta' xKK^— ^_/~±* Tn' -_X?

0X?Jh Tu' 4j;_/±~?h

x/ /' j j?W ~ ! /'j _KKjj±_/~± K'_X? * %±~/~?= _?W _? /X% ±~ /~?= _±j —~;X?J _ / _ — ~=/

/'j =%jjW ~! XJ'/ X? _ KX±K^_± ~±> X/ X?=XWj _ = /_ X? j== =/jj % X%j _ / ;_K^^—h qj±j* [j

>±Xj!° !~~[ TX? ZjK/X~? nhmhm' /'j K'_X? ~! _KKjj±_/X~? !~± % ±~ /~?= _?W _? /X% ±~ /~?=

TX? ZjK/X~? nhmha'h , j/_ X= ~! /'j _KKjj±_/X~? %±~Kj== K_? >j !~^?W X? DaVh

nhmhm L ±~ /~?=

4 ' j K'_X? ~! % ±~ /~ ? _KKjj±_/X~? J~j= _= !~~[=e

■ q ~/ '°W±~Jj? J_= T!±~— _? ~ ±W X? _ ±° >~ //j ~ ! '°W±~Jj? J_=' X= %_==jW /' ±~^J'

_ Wj;XKj ['XK' j ] /±_K /= ?jJ_/X;j '°W±~Jj? X~?= _?W _KKjj±_/j= /'j— /~ mt 9j1h

0


CH.-\PTER 3

EXPERC\IE:\"T-\L .-\PPAR.-\ TCS

\\'e briefly describe the particle accelerator and the particle detector used to take

the data used in the analysis described in Chapter i. These data were taken dur

ing a period of accelerator operation coined ··Run I"' which lasted from 1985-1996.

Currently. ··Run rr· is underway in which many improvements were made both to

the accelerator and the detector. One of the clPtPctor impron•ments is discussed in

Sections 5.1 and 5.2.

:3.1 The Particle .-\ccelerator

Tiu• particle accelerator which pro,·ided the proton-antiproton collisions for tlu•

analysis dt1scrilied in Chapter i is located at Fermi :'\ atiunal .-\ccelerntor Laborn wry

in Batavia. Illinois. The accelerator complPx. which consists of sewral different an:el

erators connected in s1•quPnce. is shown in Figure 3.1. For protons. the acct'lnation

sequence is: ( 1) Cockcroft-Walton. (2) Linac. (:3) Booster. (-1) .\Iain Ring. (5) Te\·a

tron. For antiprotons. the sequence is: ( 1) Debuncher. (2) .-\ccumulator, (3) >.lain

Ring. (-!) Te\·atron .

. -\t the end of the accelerator chain. protons and antiprotons are mo,·ing at almost

the speed of light in a circular orbit inside a stainless steel pipe at vacuum. Here, we

briefly follow ( in Section 3. 1. 1) the chain of acceleration for protons and anti protons

(in Section 3.1.2). Details of the acceleration process can be found in [2].

3.1.1 Protons

The chain of proton acceleration goes as follows:

• Hot hydrogen gas (from an ordinary bottle of hydrogen gas) is passe<l through

a device which extracts negative hydrogen ions an<l accelerates them to 18 keV.

8

w *UY £UY4

cYÛ!;„^„Y >^„;*42 £UY4

cYÛ!;„^„Y( /;„^„Y(

T„„(^2;

dUY*bE2K*^;„Y g, B

v„b—;„3^L<*V^„Y

BXJ^±j nhme 4'j Bj±—X_> _KKjj±_/~± K~—%j]h B±~— DI♦h

■ 4 'j '°W±~Jj? X~?= _±j X?7jK/jW X? /~ _ g ~ K 9 K ± ~ ! / E 6 _ / ~ ? jjK/±~=/_ /XK _KKjE

j±_ /~±h ['j±j _ %~ /j? /X_ WX!!j±j?Kj _KKjj±_/j= /'j ?jJ_/X;j X~?= /~ pss 9j1h

■ 4 'j X~?= _±j / ±_ ? =% ~ ±/j W /~ _ muc — j/j± ~?J X?j_± _KKjj±_/~± T) X? _K ' h 4 'j

)—_K _KKjj±_/j= /'j X~?= ;X_ ma ±_W X~ !±j*^j?K° T0 B' K_;X/Xj= /~ _? j?j±J° ~!

usmhc -j1h

■ 4 'j '°W±~Jj? X~?= _ ±j X?7jK/jW X? /~ /'j ?j]/ _KKjj±_/X?J =/_Jj* /'j y ~ ~ = /j ± *

;X_ 5>q04— —€5>q*4— <*$—5N<£*B y ~ /' /'j X~? > j_— _?W /'j >j_— ~! _±j_W°

K X±K^ _ /X?J %±~/~?= X? /'j y~~=/j± _±j %_==jW /' ±~ ^ J ' _ %£4]—4 T/[~ _W7_Kj?/

WX%~j — _J?j/= ~! ~%%~=X/j %~_±X/°' X? ~±Wj± /~ — j±Jj /'j X~? >j_— [X/' /'j

% ±~ /~? >j_—h 4'j K~—>X?jW >j_— X= /'j? =j? / /' ±~^J' _ K _ ±>~? !~X ['XK'

= /± X%= — ~=/ q G X~?= ~ ! /'j X± /[~ jjK/±~?=h 4 'j >j_— X= =j?/ /' ±~^J' _?~/'j±

W~JjJ ['XK' =/jj±= _?° ±j— _X?X?J q< X~?= X? /~ _ >j_— W ^ — % _?W ±j=/~±j=

b


Figure :3.1: The Fermilab acc:eleratur mmplt>x. From : l:.

• The hydrogen ions are injected into a Cockcroft- \Val ton electrostatic accel

erator. where a potential difference acceh•rates the negative ions to ,50 ke\·.

• The ions are transported to a 1-15 meter long linear accelerator ( Li nae). The

Linac.: accelerates the ions via 12 radio frequPncy (RF) cavities to an e!1ergy of

-101.5 :\[e\·.

• The hydrogen ions are injected into the next accelerating stage, the Booster.

via charge exchange injection. Both the ion beam and the beam of already

circulating protons in the Booster are passed through a dogleg ( two adjacent

dipole magnets of opposite polarity) in order to merge the ion beam with the

proton beam. The combined beam is then sent through a carbon foil which

strips most H- ions of their two electrons. The beam is sent through another

dogleg which steers any remaining H- ions into a beam dump and restores

9

/'j % _ /' ~! /' j %±~/~?= X? /' j y~~=/j±h 4 'j y~~=/j± X= _ % ±~ /~? =°?K'±~ /±~?

[ X/' _ ±_WX^= ~ ! pchc —j/j±=h 4 ' j %±~/~?= X? /'j y ~~=/j ± _±j 9j%/ X? _ = /_> j

K X±K^_± ~±>X/ ^= X?J br K~—>X?jWE!^?K/X~? W X% ~ j i* ^ _ W ±^ % ~ j —_J?j/=h x!/j±

< n ■ ms^ % ±~ /~?= _ ±j /±_?=!j±±jW !±~— /'j )X?_K /~ /'j y ~~=/j ±h mp 0 B K_;X/Xj=

_ ±j ^=jW /~ _KKj j±_ /j /'j % ±~ /~?=h v? /'j y~~=/j±* % ±~ /~?= K~jK/ X? 9R5v—N1B

= /_> j _KKjj±_/X~? ±jJX~?=* _ ? W !~±— 9R*5>—1 ~! %±~ /~?=h x !/j± _>~^/ ashsss

±j;~^/X~?= _ ±~ ^ ? W /'j y~~=/j± ±X?J* /'j % ±~ /~? >^?K'j= '_;j >jj? _KKjj±_/jW

/~ t kj1h

■ 4 'j - _ X? 0 X ? J * _ %±~/~? =°?K'±~ /±~? [X/' _ m 9 X~— j/j± ±_WX^=* X= /'j ?j]/

_KKjj±_/X?J = /_Jj h v/ K~?=X=/= ~ ! vZ 0B K_;X/Xj=h ppu W X%~ j —_J?j/= _?W aus

*^_W±^%~ j — _J?j /= h 6'j? j?~^J' _? /X%±~ /~?= '_;j >jj? = /~ ±jW X? /'j xKKÊ

— ^ _ /~ ± T=jj ZjK /X~? nhmha'h !X!/jj? %±~/~? >^?K'j= _±j /_9j? !±~— /'j y~~=/j±*

X? 7jK/jW X?/~ /' j - _X? 0X?J* _KKjj±_/jW /~ mcs kj1 _?W K~_j=KjW X?/~ _ =X?Jj

>^?K' K~?=X=/X?J ~! < mc ■ msms %±~/~?=h

■ 4 ' j =X?Jj K~_j=KjW %±~/~? >^?K' X= !X?_° X?7jK/jW X?/~ /' j 4 j ; _ / ± ~ ? h ['XK'

= X/= X? /'j =_— j /^??j rc K— >j~[ /'j - _X? 0X?Jh 4 ' j 4j;_/±~? ^=j= ppu

W X%~ j _?W amr *^_W±^%~ j — _J?j /= /~ 9jj% /'j %±~ /~?= T_?W _? /X%±~/~?=* =jj

ZjK/X~? nhmha' X? _ = /_> j K X±K^_± ~±>X/h )♦?X9j /'j — _J?j /= X? /'j _KKjj±_/~±=

^% /~ /'X= %~ X? /* /' j 4j;_/±~? — _J?j/= _±j =^%j±K~?W^K /X?J —_J?j/=* K~~jW

[ X/' X*^XW 'jX^— h ZX] >^?K'j= ~! %±~/~?= _±j X?7jK/jW X? /~ /'j 4j;_/±~? _=

Wj=K±X>jW _>~;j _ ? W T_!/j± =X] >^?K'j= ~! _? /X% ±~ /~?= '_;j _=~ >jj? X?7jK/jW'

_KKjj±_/jW /~ /' j X ± !X?_ j?j±J° ~ ! bss kj1h

4 ' j j? /X±j %±~Kj== Wj=K±X>jW _>~;j /_9j= _>~^ / m —X?^/jh

ms


the path of the protons in the Booster. The Booster is a proton synchrotron

with a radius of 75.~ meters. The protons in the Booster are kept in a stable

circular orbit using 96 combined-function dipole/quadrupole magnets. After

,.._, 3 · 1012 protons are transferred from the Linac to the Booster. 1 i RF cavities

are used to accelerate the protons. In the Booster. protons collect in buckets.

stable acceleration regions, and form bunches of protons. .-Uter about 20.000

revolutions around the Booster ring. the proton bunches h,we been accelerated

to 8 Ge\·.

• The j\Jain Ring. a proton synchrotron with a 1 kilometer radius. is the next

accelerating stage. It consist,:; of 18 RF cavities. 77-! dipole magnets and :2-!0

quadrupole magrwts. \\'lwn enough antiprutons h,n-e bt•t>n stored in the .\cocu

ruulator (see Section :3. 1.:2). fifteen proton bundws arP taken from tlw Buostt>r.

injected into the :\Iain Ring. accelerated to l;j0 Ge\· and coalesced into a single

bund1 consisting of --... 1.'5 · 1010 protons.

• The single coalesced proton bunch is finally injected into the Tevatron. which

sits in the same tunnel 65 cm below the .\Iain Ring. The Tevatron uses ,7-l

dipole and 216 quadrupole magnets to keep the protons (and a.ntiprotons. see

Section 3. 1.2) in a stable circular orbit. Cnlike the magnets in the accelerators

up to this point, the Tevatron magnets are superconducting magnets, cooled

with liquid helium. Six bunches of protons are injected into the Tevatron as

described above and ( after six bunches of anti protons have also been injected)

accelerated to their final energy of 900 GeV.

The entire process described above takes about 1 minute.

10

nhmha x ? /X% ±~ /~?=

x ?/X% ±~ /~?= _ ±j ?~ / %±j=j?/ X? ~±WX?_±° — _//j ± h 6j K_??~/ /_9j _ > ~ / / j ~ ! _?/XE

';W±~Jj? J_=h = / ± X% /' j _? /XEj jK/±~?= ~!! /'j _?/XE'°W±~Jj? _ /~ — = X? /'j J_= _ ? W !X?W

~^±=j;j= [X/' _ ? / X% ±~ /~?= h v? /' j jj—j?/= _ ±~^?W ^=h /'j±j _±j =X— %° ?~ =~^±Kj= ~!

_ ? / X— _ / /j ± h Z~h [j '_;j /~ — _9j _? /X% ±~ /~?= _?W /' j ? _KKjj±_/j /'j— h 4'X= %±~Kj==

X= — ^K' =~[j± / ' _ ? K~jK/X?J _ ? W _KKjj±_/X?J %±~/~?=h

■ x ?/X% ±~ /~?= _ ±j —_Wj >° j ] /±_K / X? J %±~/~?= [X/' _? j?j±J° ~! mas k j 1 !±~—

/'j -_X? 0 X?J _?W W X±jK /X?J /'j— _/ _ PXK9j /_±Jj/h v? /' j ?^Kj_± ±j_K/X~?=

/' _ / /_9j % _Kj ['j? /'j % ±~ /~ ? = 'X/ /'j /_ ±Jj / * _ =%±_° ~ ! =jK~?W_±° %_±/XKj=*

X?K^WX?J _ ? / X% ±~ /~?= * _ ±j %±~W^KjWh x>~^/ m _? /X% ±~ /~? X= %±~W^KjW !~± j;j±°

msAm %±~/~?= / ' _ / 'X/ /'j /_ ±J j / h x?/X%±~/~?= _±j !~K^=jW X?/~ _ >j_— ^=X?J _

K°X?W±XK_ X /' X^ — j?=h x %^=jW —_J?j/ X= /'j? ^=jW /~ Wj!jK/ ?jJ_/X;j°

K'_±JjW t k j 1 %_±/XKj= X? /~ _ /±_?=%~±/ X?j /~ /'j ,j>^?K'j±h

■ 4 'j , j > ^ ? K ' j ± W~j= j]_K° [ '_/ X/= ?_—j X—%Xj=h ZX?Kj /'j _? /X% ±~ /~?= [j±j

K±j_ /jW [X/' >^?K'j= ~! % ±~ /~?= * /'j° /~~ _±±X;j X? /'j , j>^?K'j± [X/' _ ?_±±~[

=%±j_W X? / X— j * Xhjh* >^?K'jWh 4 'j ,j>^?K'j± X?K±j_=j= /'j / X— j =%±j_Wh v/ _=~

^=j= 1N£5>q1N<5 5££]<*4 /~ WjK±j_=j /'j %'_=j =%_Kj ~! /'j >j_— h

■ 4 ' j _ ? /X% ±~ /~ ? = _±j /'j? /±_? =!j ±±jW /~ /'j x K K ^ — ^ _ / ~ ± * _ = /~±_Jj ±X?J ['XK'

=/~±j= _ ? / X% ±~ /~ ? = ^?/X j?~^J' '_;j >jj? K~jK/jW /~ X?7jK/ X?/~ /'j - _X? 0X?Jh

x= _? /X% ±~ /~ ? = _±j _KK^— ^_ /jW T_ %±~Kj== 9?~[? _= N=/_K9X?JN'* = /~K'_=/XK

K~~X?J X= ^=jW /~ WjK±j_=j /'j —S<NNq*5— ~! /'j >j_—h x ? /X% ±~ /~?= _ ±j _KKÊ

— ^_ /jW _ / _ ± _ / j ~! _> ~ ^ / c 4 s ms _? /X% ±~ /~?= %j ± '~^±h

■ x !/j± _>~^ / t '~^±=* /'j N=/_K9N ~! _? /X% ±~ /~?= X= =^!!XKXj?/° _±Jj /~ >j ±j;j±=j

X? 7jK/jW X?/~ /' j - _ X ? 0 X ? J !~± _KKjj±_/X~?h x!/j± =X] >^?K'j= ~! % ±~ /~ ? =

'_;j _±j_W° >jj? X?7jK/jW X? /~ /'j 4j;_/±~?* _ %~±/X~? ~ ! /' j _? /X% ±~ /~? =/_K9

mm


3.1.2 Antiprotons

.-\ntiprotous are not present in ordinary matter. \\"e cannot take a bottle of anti

hydrogen gas. strip the anti-electrons off the anti-hydrogen atoms in the gas and find

ourselves with antiprotons. In the elements around us, there are simply no sources of

antimatter. So. we have to make antiprotons and then accelerate them. This process

is much slower than collecting and accelerating protons.

• .-\.ntiprotons are made by extracting protons with an energy of 120 Ge\· from

the .\Iain Ring and diret:ting them at a :'\ickel target. In the nudear reactions

that takP place when the protons hit the target. a. spray of secondary particles.

including antiprotons. are produced .. .\bout l antiproton is produceJ for evPry

105 protons that hit the target. . .\ntiprutons are focused into a beam using a

cylindrical lithium lens. A pulsed magnet is then usPd to <h•f!Pct negatiwly

d1argPd S Ge\· particles into a transport line to tlw Debundwr.

• The Debuncher Jars Pxacly what its name implies. Since the antiprotuns were

created with bunches of protons. they too arrive in tht> Ddrnncher with a narrow

spread in time. i.e .. bunched. The Debuncher increases the time spread. It also

uses .5tochastic cooliny to decrease the phase space of the bf-',:Ull.

• The antiprotons are then transferred to the Accumulator. a storage ring which

stores antiprotons until enough have been collected to inject into the ~Iain Ring.

As antiprotuns are accumulated ( a process knm,·n as .. stacking··). stocha:stic

cooling is used to decrease the emittance of the beam. ...\ntiprotons are accu

mulated at a rate of about 5-10 10 antiprotons per hour.

• .-.\.fter about 8 hours, the "stack" of antiprotons is sufficiently large to be reverse

injected into the lVIain Ring for acceleration. After six bunches of protons

have already been injected into the Tevatron, a portion of the antiproton stack

11

!±~— /' j x KK^— ^_/~± X= X?7jK/jW X? /~ /'j - _X? 0X?Jh x= [ X/' %±~/~?=* /'j

_ ? /X% ±~ /~?= _±j _KKjj±_ /jW /~ FeO k j1 _?W K~_j=KjW X?/~ _ =X?Jj >^?K'h x

/°%XK_ >^?K' K~?=X=/= ~! eCe *FOms _? /X% ±~ /~?= h

■ Q?j >° ~?j* =X] _ ? / X% ±~ /~ ? >^?K'j= _±j X?7jK/jW X? /~ /'j 4 j ; _ / ± ~ ? —~;X?J X?

/'j ~%%~=X/j W X±jK/X~? ±j_/X;j /~ /'j %±~/~?=h 4 ' X= %±~Kj== ^=j= _ > ~ ^ / '_! ~!

/'j _? /X% ±~ /~? = /_K9 X? /'j xKK^— ^_/~±h

GCFCG g~X=X~?=

Q?Kj _ =X] %±~/~? _?W =X] _? /X%±~ /~? >^?K'j= _±j K~^? /j±KX±K^ _ /X?J X? /'j 4j;_E

/±~?h /'j° _ ±j _KKjj±_/jW /~ ‘OO kj1h y ~ /' /'j % ±~ /~? _?W _? /X% ±~ /~?= KX±K^_/j X?

/'j =_— j >j_— %X%j _?W /' j X± ~±>X/= _±j =%_ /X_ ° =j%_±_ /jW >° ?G*V ?^? h 6'j? /'j

>j_— j?j±JXj= ±j_K' ‘OO k j1 h =%jKX_ *^_W ±^%~ j — _J?j /= X?=/_jW X? /'j g, B T=jj

ZjK/X~? GCE' _?W ,Q j]%j±X— j?/_ '_= _ ±j ^=jW /~ !~±Kj /'j /[~ >j_— = /~ NK~XWjN

_ / /'j Kj?/j± ~! /'j Wj /jK /~ ±= h g~X=X~?= ~KK^± j;j±° GCeLphC 4'j K~X=X~?= W~ ?~/

~KK^± _ / /'j =_— j %~X?/ X? =%_Kj !±~— K~X=X~? /~ K~X=X~?h 0_/'j±* /'j ]RS<*£R1

0—4<£* X= _ J_^==X_? W X= /± X>^ / X~? _>~^/ /'j ?~— X?_ X? /j ±_K /X~? %~X?/ [X/' _ [XW/' ~!

GO K— X? /'j ~?WX/^WX?_ W X±jK /X~? T_~?J /'j >j_— _]X=' _?W GeL£* X? /' j /±_?=;j±=j

W X±jK/X~? T%j±%j?WXK^_± /~ /'j >j_— _]X='h 4°%XK_° /'j±j X= ~?° #m X? /j±_K/X~? %j±

>^?K' K±~==X?J* Xhjhh j;j±° / X— j _ %±~/~? _ ? W _? /X% ±~ /~ ? >^?K' _±j !~±KjW /~ K~XWj

>° /'j =%jKX_ *^_W±^%~j — _J?j/= * ~?° ~?j % ±~ /~? !±~— /'j %±~/~? >^?K' _?W ~?j

_ ? / X% ±~ /~ ? !±~— /'j _? / X% ±~ /~ ? >^?K' _K /^_ ° j]%j±Xj?Kj _ = /±~?J X? /j±_K /X~? [X/'

j_K' ~/'j±h

x JX;j? =X] %±~/~? _?W _? /X% ±~ /~? >^?K'j= K~?/X?^j K°KX?J X? /'j 4j;_/±~? !~±

0*F0 '~^±= TK_jW _ 1N£0—{B 4 ' j X?=/_? /_?j~^= ^—X?~=X/°* Wj!X?jW _=

d s W ]w 3 „up±K±E

FE


from the . ..\ccumulator is injected into the 1lain Ring. ...\s with protons, the

anti protons are accelerated to 150 Ge V and coalesced into a single bunch. ...\

typical bunch consists of 5.5 -10 10 antiprotons.

• One by one, six antiproton bunches are injected into the Tevatron moving in

the opposite direction relative to the protons. This process uses about half of

the antiproton stack in the . .\ccumulator.

3.1.3 Collisions

Once all six proton and six antiproton bund11•s are countercirculating in tht> Te\·a

tron. they are acceh•rate<l to 900 G1·\·. Both thP proton and antiprotuns circ11latP in

the same l.wampipe and their orbits are spatially sPparated by ,.__,3_5 mm. \\"hr>n tlw

lwam energies rt•ach 900 Ge\". special quadrupole magnets installt>d in thP CDF (sPe

Section 3.2) and DO experimental halb are used to force the two beams to ··collide··

at the center of the detectors. Collisions on:ur every 3.5ps. The collisions do not

occur at the same point in space from collision to collision. Rather. the luminous

region is a gaussian distribution about the nominal interaction point with a width of

30 cm in the londitudinal direction (along the beam axis) and 35Jltn in the transverse

direction (perpendicular to the beam axis). Typically there is only "'l intt•raction per

bunch crossing. i.e., every time a proton and antiproton bunch are forced to collide

by the special quadrupole magnets, only one proton from the proton bunch and one

antiproton from the antiproton bunch actually experience a strong interartion with

each other.

:\ given six proton and antiproton bunches continue cyding in the Tevatron for

8-18 hours ( called a store). The instantaneous luminosity, defined as

L = Np~YpB/0

4rra2

12

(3.1)

['j±j M • _ ? W h2% _±j /'j ?^— >j± ~! %±~/~?= _?W _? /X% ±~ /~?= %j± >^?K' ±j=%jK/X;j°h

o X= /'j ? ^ — > j ± ~! >^?K'j= ~! j_K' /°%jh i 3 X= /'j ±j;~^/X~? !±j*^j?K° ~! /'j >^?K'j=*

_?W q ♦ X= /' j K±~==E=jK/X~?_ _±j_ ~ ! _ >^?K'* WjK±j_=j= j]%~?j?/X_ ° W^±X?J /' j =/~±jh

,^±X?J _ = /~ ±j * /'j _KKjj±_/~± K'_X? >j~[ /'j 4j;_/±~? ±j— _X?= _K/X;j* =~ / ' _ / _ !/j±

/'j >j_— !±~— _ JX;j? =/~±j X= W ^ — % jW * !±j=' >^?K'j= _±j ±j_W° /~ >j X? 7jK/jW X?/~

/'j 4j;_/±~?h

nha 4 ' j L_±/XKj ,j/jK/~±

Q?j ~! /' j /[~ %_±/XKj Wj/jK/~±= ^=jW /~ ~>=j±;j /'~ % ±~ /~? E_? /X% ±~ /~? K~X=X~?=

_ / Bj±—X_> X= K_jW /'j g~XWj± , j/jK/~± _ / Bj±— X_> Tg , B 'h v/ X= _ — ^ /X%^ ±%~=j

Wj/jK /~ ± /' _ / [jXJ'= chsss /~?= _?W X= _%%±~]X— _/j ° _ ms — j/j ± 'XJ'h ap — j/j ± ~?J

K°X?Wj±h 6 ' j? _? X?j_=/XK X? /j±_K /X~? >j/[jj? _ %±~/~? _?W _? /X% ±~ /~? /_9j= %_Kj*

/'j %±~/~? _ ? W _? /X% ±~ /~? _±j >±~9j? ^%h _?W WX!!j±j?/ 9X?W= ~ ! %_±/XKj= j—j±Jj !±~—

/'j X? /j±_K /X~? %~X?/h 4 'j g, B W j /jK /~ ± K°X?W±Xj_° =^ ±±~^?W= /'j >j_— X?jh =~

/' _ / %_±/XKj= j— j±JX?J !±~— /'j X? /j±_K/X~? %~X?/ [X/' =~—j — ~— j? /^— K~— %~?j? /

%j ±%j?W XK^ _ ± /~ /'j >j_—X?j [X j?K~^?/j± /'j g , B Wj /jK /~ ± _?W %±~W^Kj =XJ?_=

X? X/= ;_±X~^= =^>=°=/j— =h 4'j=j =XJ?_= _±j jjK/±~?XK_° — j_=^±jW _?W ^=jW /~

±jK~?=/±^K/ * ^ _? /X / Xj = =^K' _= /'j j?j±J°* — ~— j?/^— * XWj?/X/° _? W /±_ 7jK /~ ±° ~ ! /'j

%_±/XKj=h

4'j g , B Wj /jK /~ ± X= K°X?W±Xj_° =°— — j/±XK _> ~ ^ / /'j >j_— X?j _?W !~±[_±WE

>_K9[_±W =° — — j /± XK _>~^ / /'j X? /j±_K /X~? %~X?/h 4 'j K~~ ±W X?_ /j =°=/j— ^=jW >°

g , B X= Kj? /j ±jW ~? /'j ?~—X?_ X? /j±_K/X~? %~X?/h 4 'j %~=X/X;j ]E_]X= %~X?/= _~?J

/'j >j_—X?j X? /'j WX±jK/X~? ~! /'j %±~/~?= Tj_=/* /~[_±W= g'XK_J~'* /'j %~=X/X;j

°E_]X= %~X?/= ;j±/XK_° ^%[_±W= T/~[ _±W= /'j =9°'* _?W /'j %~=X/X;j ]E_]X= %~ X? /=

±_WX_° ~^ /[ _±W= X? /'j '~±X\~?/_ % _?j ~! /'j 4j;_/±~?h 4 ' j %~_± _?Jj Ts' X=

— j_=^±jW [ X/' ±j=%jK/ /~ /'j %~=X/X;j ]E_]X=h 4°%XK_°* ~K_/X~?= ~! %_±/XKj= X? /'j

mn


where Sp and Sp are the number of protons and antiprotons per bunch respectively.

B is the number of bunches of each type. / 0 is the re\·olution frequency of the bunches.

and a 2 is the cross-sectional area of a bunch. decrea.-;es exponentially during the store.

During a store, the accelerator chain below the Tevatron remains active. so that after

the beam from a given store is dumped. fresh bunches are ready to be injected into

the Tevatron.

3.2 The Particle Dett•ctor

One of the two particle detectors used to obsPrve the proton-antiprotou collisions

at Fermilab is called thP Collider DetPctor at Ft>rmilab (CDF). It is a multipurpost•

deteuur that Wf'ighs 5.000 terns and is approximately a lO meter high. 27 nwti'r long

cylinder. \\'hen an ineli.L'it.ic interaction betWPt-n a proton and antiproton takt'S pla.l'P.

thP proton and antiproton are brokPu up. and diffrrt>ur kinds of particlPs PlIIPq?;e from

tlw interaction puint. Tlw CDF d1~tector cylindri<'ally surrounds the beamlirw. so

that particles emerging from the interaction point with some momentum component

pP.rpendicular to the beamline will t'ncounter the• CDF detector and produce signals

in its various subsystems. Thesf~ signals are electronically me;_L-;urecl and ust>d to

rt->constr11ct quantities such a.s the energy. momentum. identity and trajectory of the

particles.

The CDF detector is cylindrically symmetric about the beamline and forward

backward symmetric about the interaction point. The coordinate system used by

CDF is centered on the nominal interaction point. The positive .:-,L\:is points along

the beamline in the direction of the protons (east. towards Chicago). the positive

y-axis points vertically upwards ( towards the sky), and the positive .r-axis points

radially outwards in the horizontal plane of the Tevatron. The polar angle (0) is

measured with respect to the positive .:-,L\:is. Typically, locations of particles in the

13

W j /j K /~ ± _±j XWj?/X!XjW >° /'j )~±j?/\EX?;_±X_? / * ^ _ ? /X /° %=j^W~±_%XWX/°* 0$B Wj!X?jW _=

+ f E ~J T /_ ? X\j{{ Tnha'

_? W >; /'j _\ X— ^/'_ _?Jj T~' ['XK' X= — j_=^±jW K~^?/j±K~K9[X=j !±~— /'j %~=X/X;j

]E_]X=h x /'±jjEWX—j?=X~?_ ;Xj[ ~ ! /' j g , B Wj /jK /~ ± X= ='~[? X? B XJ^±j nhah x ;Xj[

~! ~?j *^_W±_? / ~! /' j Wj/jK/~± X= ='~[? X? BXJ^±j nhnh 4'j Wj/jK /~ ± A= =^>=°=/j— =

K_? >j K_==X!XjW X?/~ /'±jj —_X? K_/jJ~±Xj=e

■ 4±_K9X?J =°=/j— h

■ g_~±X—j/j±=h

■ - ^~? Wj/jK/~±=h

qj±j* [j >±Xj!° Wj=K±X>j /'j=j W j /jK /~ ± =°=/j— = _= /'j° j]X=/jW X? 0^? vh x — ~±j

K~— %j /j Wj=K±X%/X~? ~! /'j g , B W j /j K /~ ± K_? >j !~^?W X? Dn7h 4 'j Wj/jK/~± [_=

—~WX!XjW !~± 0^? vv ['XK' X= K ^ ±±j ? / ° ^?Wj±[_°h 4 ' j —~WX!XK_/X~?= /~ /'j L ^J

K_ ~ ± X— j/j ± _±j WX=K^==jW X? =~—j W j /_ X ZjK/X~? chmh

nhahm 4 ' j 4±_K9X?J Z°=/j—

4 ' j /±_K9X?J =°= /j— X= K~— %~=jW ~! /' ±jj WX!!j±j?/ Wj/jK/~±=h Z^±±~^?WX?J /' j

> j_— % X% j X= _ =XXK~? = /± X% Wj/jK/~±* /'j Z15 TZXXK~? 1j±/j] ,j/jK/~±'h Z^±±~^?WX?J

/'j Z1 5 X= _ /X—j %±~ 7jK /X~? K ' _ — > j ± K_jW /'j 2 4 5 T1j±/j] 4±_K9X?J g '_— >j±' *

_?W =^±±~^?W X?J /'j 2 4 5 X= _ Jj/= W ± X! / K'_— >j±* /'j g 4 g Tgj?/±_ 4±_K9X?J g ' _ — E

>j±'h 4 ' j =XXK~? W j /j K /~ ± %±~;XWj= /' j — ~=/ %±jKX=j /±_K9X?J X?!~±—_/X~?* /'j / X— j

%±~ 7jK /X~? Wj/jK/~± %±~;XWj= X?!~±— _/X~? _ > ~ ^ / /'j \ %~=X/X~? ~! _? j;j?/A= X? /j±_KE

/X~? %~ X? /* _?W /'j J_= W±X!/ K'_— >j± X= ^=jW /~ ±jK~?=/±^K/ /'±jjEWX—j?=X~?_ /±_K9=

!±~— %_±/XKj= /±_;j±=X?J /'j W j /jK /~ ± h x ~ ! /'j=j Wj /jK /~ ±= _±j =^±±~^?WjW >° _

=^%j±K~?W^KX?J =~j?~XW ['XK' %±~;XWj= _? _]X_ — _J?j/XK !XjW ~! mhum 4j=_h B±~—

mu


detector are identified by the Lorentz-im·ariant quantity pseudorapidity. ,,. defined as

TJ = -log(tan(0/2)) (3.2)

and by the azimuthal angle (o) which is measured counterclockwise from the positive

.r-axis . .-\ three-dimensional view of the CDF detector is shown in Figure 3.2 . .--\ view

of one quadrant of the detector is shown in Figure 3.3. The detector·s subsystems

can be classified into three main categories:

• Tracking system.

• Calorimeters.

• '.\Iuon detectors.

Here. we bri11 fty dt>scribt> tht>se dett'ctur systf'ms as tlwy 1•xiswd in Run I. .-\ more

rnmplet.P description uf t!111 CDF det.t•ctor <:an bP funnel in [:3\. Tht> dt>tPctur was

modified fur Run II which is currently undt>rway. The modifications to th11 Plug

calorimeter are discussed in some dPtail Section 5.1.

3.2.1 The Tracking System

The tracking sy"item is composed of thrP" different detectors. Surrounding the

beampipe is a silicon strip detector. the S\.X (Silicon \'ertex Detector). Surrounding

the S\'X is a time projection chamber called the \"TX (\·ertex Tracking Chamber).

and surrounding the \'TX is a gas drift chamber. the CTC (Central Tracking Cham

ber). The silicon detector provides the most precise tracking information. the time

projection detector provides information about the z position of an event's interac

tion point. and the gas drift chamber is used to reconstruct three-dimensional tracks

from particles traversing the detector. All of these detectors arc surrounded by a

supcrconducing solenoid which provides an axial magnetic field of 1.-U Tesla. From

1-1

—

BXJ^±j nhae x /'±jjEWXX?j?=X~XXKX ;Xj[ ~! /'j g , B Wj/jK/~±h B±~— DvVh

/'j K^ ±;_ /^ ±j ~! K'_±JjW %_±/XKj /±_K9= X? /'j / ±_K9 X? J ;~^—j* /'j — ~— j?/^— ~! /'j

%_±/XKj= K_? 'j — j_=^±jWh 4'j — ~— j? /^— • X= J X;j? >°

• f + o • Tnhn'

['j±j + X= /'j K'_±Jj ~ ! /'j %_±/XKjh o X= /'j — _ J ? j / XK 'jW = /±j?J/' * _?W • X= /'j

±_WX^= ~! K^±;_ /^ ±j ~ ! /' j %_±/XKj♦= /±_ 7jK/~±° h

nhahFCF ZXXK~? 1j±/j] , j/jK/~± TZ15'

4 'j ZXXK~? 1j±/j] , j/jK/~ ± ^=jW >° g , B W ^ ± X? J X/= !X±=/ ±^??X?J %j±X~W T0^?

mx'h [_= /'j !X±=/ =XXK~? ;j±/j] W j /jK /~ ± j;j± ^=jW _ / _ '_W±~? K~XWj±h x Wj/_XjW

Wj=K±X%/X~? ~! /'j Wj /j K /~ ± A= K~?= /±^K/X~? _?W % j ±!~ ±— _? Kj K_? >j !~^?W X? Du7h

4 'j W j /j K /~ ± K~?=X=/= ~! /[~ K°X?W±XK_ >_±±j= T=XWjE>°E=XWj _~?J C{ ['XK' K~_]E

X_° =^ ±±~ ^ ? W /'j >j_— %X%j h x /'±jjEW X— j?=X~?_ ; Xj[ ~! ~?j ~! /'j >_±±j= X= ='~[?

mc


Figure 3.2: .-\ three-dimensional view of the CDF <let1:ctor. From [1].

tlw cun·ature uf charged particle tracks in th1• tracking \·olumP. the momentum of the

particles can be measured. The momentum p is given l,y

P = qBp (3.3)

1\ here q is the charge of the particle. B is the magneLic fieid strength. and p is the

radius of curvature of the particle·s trajectory.

3.2.1.1 Silicon \·ercex Detector (S\"X)

The Silicon \·ertex Detector used by CDF during its first running period (Run

1.-\), was the first silicon vertex detector ever used at a hadron collider. .-\ detailed

description of the detector's construction and performance can be found in [4].

The detector consists of two cylindrical barrels ( side-by-side along =) which coa..-.;:

ially surround the beampipe . .-\ three-dimensional view of one of the barrels is shown

1.5

vCf

00 N— LL L )

BXJ^±j nhne x ;Xj[ ~! ~?j *^_W±_?/ ~! /'j g,B Wj/jK/~± ='~[X?J /'j ;_±X~^= Wj/jK/~± K~—%~?j?/= _?W /'j g,B K~~±WX?_/j =°=/j—h B±~— ’mVh

X? BXJ^±j nhuh w_K' >_±±j X= achc K— ~?J T_~?J C{ [ X/' _ ahmc K— =j% _±_ / X~ ? >jE

/[jj? /'j /[~ >_±±j= _ / K f sh —_9X?J /'j /~ /_ _K/X;j j?J /' ~! /'j W j /j K /~ ± cm K—h

ZX?Kj /'j X? /j ±_K / X~? ±jJX~? 'X/= _ =%±j_W ~! q < ns K— _ > ~ ^ / K E sh /' j Z15 /±_K9

_KKj%/_?Kj X= ~?° <rsbKh 4 ' j %=j^W~±_%XWX/° K~;j±_Jj X= Q0®Q d mhbh

w_K' >_±±j X= WX; XWjW X?/~ FE _\X—^/'_ =jK/X~?= °^—%4—1{ j_K' =^ > /j ? W X? J ns“h

w_K' [jWJj K~?=X=/= ~! !~^± _°j±= ~! =XXK~? = /± X% Wj /jK /~± — ~W^j= T ]q%%—01' [X/' /'j

X??j±—~=/ _°j± _ / _ ±_W X^ = ~ ! ahtr K— _?W /'j ~^/j±— ~=/ _°j± _ / _ ±_W X^ = ~! phtp

K—h 4'j _WWj±= T=jj B XJ^ ±j nhc' K~?=X=/ ~! /' ±jj thc K— ~?J =X?JjE=XWjW =XXK~? =/± X%

Wj/jK/~±= [ X/' ±j_W~^ / = /± X% = ±^??X?J %_±_j /~ /'j >j_— h Q ? /'j X??j± /' ±jj _°j±=

~! _WWj±=* /'j ±j_W~^ / = /± X% = '_;j _ %X/K' ~ ! rs \Bq* [ 'j±j_= /'j ~^ /j ±— ~ =/ _°j±A=

_WWj±= '_;j = /± X% = ~! cc i X— %X/K'h

4'j W j /jK /~ ± '_= _ /~ /_ ~! br _WWj±= _?W _ /~ /_ ~! ur*sts K'_??j=h Q ? ° K'_??j=

['XK' ±jJX=/j± _ ' X/ _ ±j ±j_W ~^ /h B~± _ /°%XK_ j;j?/* _ > ~ ^ / xh ~! /'j /~ /_ Z15

K'_??j= _±j ±j_W ~^/h 4 ' j ±j_W~^ / /X—j !~± /' j Z15 W j /j K /~ ± X= ~?j ~! /'j ~?Jj=/

mr


.:~w~o

... ACA~~ ... I(. ~..::.tt,..,trEH

I I

/ I

/ /

figure 3.:3: :\ vie,v uf one quadrant of the CDF detector showing the various detector components and the CDF coordinate system. From [l].

in FigurP :3...!. Each barrel is 25.5 cm long (along .: ) with a 2.15 cm sPµaration I.Je

t ween the two barrels at .:: = 0. making tlu~ total active length of the detector 51 cm.

Since the interaction region ha.s a spread of a "' :30 cm a.bout .: = 0. the S\'X track

, acceptancP is only "-'tiO'X. The pseudorapidity coverage is I 'li < 1.9.

Each barrel is divided into 12 azimuthal sections ( wed yes) each subtending :30°.

Each wedge cnnsists of four layers of silirnri strip detector modules (ladders) with the

innermost layer at a radius of 2.86 cm and the outermost layer at a radius of 7.87

cm. The ladders (see Figure 3.5) consist of three 8.5 cm long single-sided silicon strip

detectors with readout strips running parallel to the beam. Ou the inner three layers

of ladders, the readout strips have a pitch of 60 ;tm whereas the outermost layer's

ladders have strips of 55 µm pitch.

The detector has a total of 96 ladders and a total of '16,080 channels. Only channels

\Vhich register a hit are read out. For a typical event, about 5o/c of the total SVX

channels a.re read out. The readout time for the S\X detector is one of the longest

16

.p~£]k GC1- u ■,]kk*Jp¥k*’p^*c> |pkW ^" c* hsv (c]]k>C .]^¥ Xp_C

±j_W~^/ /X—j= X? /'j g , B Wj/jK/~±* /°%XK_° a —=h 4 ' j Z15 %±~;XWj= %±jKX=j 0*•

X?!~±— _/X~? !~± /'j ±jK~?=/±^K/X~? ~ ! K'_±JjW %_±/XKj /±_K9=h 4'j =X?Jj 'X/ ±j=~^/X~?

%j± _°j± X= _>~^/ mni—X [X/' _ brR 'X/ j!!XKXj?K° % j ± _°j±h 4 'j ±j=~^/X~? _~[=

/'j — j_=^±j—j?/ ~! /'j =jK~?W_±° ;j±/j] ~! o '_W±~?= ['XK' /±_;j W X=/_?Kj= ~!

!P <nssEuss iX— >j!~±j WjK_°X?Jh

nhahmha 1j±/j] 4±_K9X?J g '_— >j± T1 4 5 '

4 'j 1j±/j] 4±_K9X?J g '_— >j± X= _ J_= W±X!/ K'_— >j± ~! /'j 4 L g T/X— j %±~7jK/X~?

K'_— >j±' /°%j ['XK' =^±±~^?W= /'j Z15h v/ %±~;XWj= %±jKX=j /±_K9X?J X? !~±— _/X~? X?

/'j 0 ¥ C %_?jh 4'X= j?_>j= /'j W j /j ±— X? _ / X~ ? ~! /'j ~K_/X~? _~?J /'j >j_— X?j ~!

/'j % ± X— _±° •• X? /j±_K/X~?h x=~* X! /'j±j X= —~±j /' _ ? ~?j X? /j±_K/X~? X? /'j =_— j

>^?K' K±~==X?J* /'j 1 4 5 K_? XWj?/X!° — ^/X% j %±X— _±° ;j±/XKj= _?W _==~KX_/j _ /±_K9

mp


- -.. -. ---- ' __, - _,,_ .

-----..-..----..--. __,:_ :__I._,-

---

-. ,- ~ n .n 1 --- ~ ~ .----:.. -- ,_./ '__, _,, :._ ·-

- ' -.,. _,... -

Figure :~.-1: _.\ three-dimensional view of au SVX barrel. From [lj.

readout times in the CDF detector. typically 2 ms. The S\·x pro\·ides precise r-o

information for the reconstruction of chargPd particle tracks. The single hit resolution

per layer is about 1311m with a 96%. hit efficiency per layer. The resolution allows

the measurement of the secondary vertex of B hadrons which travel distances of

c, -300--!00 µm before decaying.

3.2.1.2 \·ertex Tracking Chamber (VTX)

The \·ertex Tracking Chamber is a gas drift chamber of the TPC (time projection

chamber) type which surrounds the SVX. It provides precise tracking information in

the r - :; plane. This enables the determination of the location along the beamline of

the primary pp interaction. :\.!so. if there is more than one interaction in the same

bunch crossing, the VTX can identify multiple primary vertices and associate a track

17

; ? U ;

BXJ^±j nhce Z15 _WWj±h B±~— DvVh

/~ X/= K~±±jK/ ;j±/j] _ ~?J /'j >j_—X?jh

4 ' j C 4 5 K~?=X=/= ~! at =j%_±_ /j 4 L g —~W^j= = /_K9jW j?WE/~ Ej?W _ ~?J /'j >j_—

WX±jK /X~? h w_K' —~W^j X= WX;XWjW X? /~ /[~ mc K— ~?J W±X!/ ±jJX~?=h x/ /'j j?W ~!

/'j W±XY/ ±jJX~?=* % ±~%~±/X~?_ K'_— >j±= _±j _ ± ±_ ? J j W X? ~K/_? /= h w_K' ~K/_? / '_=

_ /j ±? _ / X? J =j?=j [X±j= _ ? W !XjW ='_% X?J [X±j= = / ± ^ ? J % j ±%j?W XK^ _ ± /~ /'j ±_WX_

W X±jK /X~? h 4 'j Wj/jK /~ ± X= aht — ~?J X? ± [ X/' _? X??j± ±_W X^= ~! 0 K— _?W _?

~^ /j ± ±_W X^= ~! aa K—h v / K~;j±= _ %=j^W~±_% XW X/° ±_?Jj ~! ’±i’ d nhch 4 'j /±_K9X?J

K'_— >j±= ^=j _ £ch*£ch — X]/^±j ~! j /' _ ? j _?W _ ±J ~ ? J_=h 6 'j? K'_±JjW %_±/XKj=

%_== /' ±~ ^ J ' /'j J_=h /'j° X~?X\j /'j J_=* _?W /'j !±jjW jjK/±~?= W ± X! / T[ X/' _ ;j~KX/°

~! urY i— i?=' X? /'j _]X_ WX±jK/X~? /~ /' j =j?=j [X±j=h 4 ' j ;~/_Jj W ± ~ % ~? /'j [X±j X=

±j_W ~ ^ / _?W _—%X!XjWh 4 ' j %~=X/X~? ~! /'j [X±j %±~;XWj= ±_WX_ X? !~ ±— _ /X~? _>~^/ /'j

%_±/XK j= /±_;j±=X?J /'j W j /jK /~ ± _?W /'j W±X!/ /X— j %±~;XWj= ~?J X/^W X?_ X?!~±—_/X~?*

mt


/

,./,,-

-------~,________ :;_ :: .:. ~ '~ -- :: .:., ::: ~J ,,Z ~

/ /

--.1'. ,, - .... --.;·'i,v'- ;'; : ,- , - / '

'fl, .. _,

/' /

/

--· . ' . :·.... -..... • '1. - '

' ':;:::-:::;--:\ ... ~·-:=: ,, ' - -- '-' . ..__, -

,...__ - ---.- ,- - ................ . - .... --

Figure 3.5: SVX ladder. From [l].

to its correct vertex along the beamline.

The \"TX consists of 28 SPparate TPC modules stacked Pnd-to-end along the beam

direction. Each module is divided into two 15 cm long drift regions .. \t the en<l of

the drift regions, proportionnl d1:1rnbcrs are arranged in octants. Each octant has

alternating sense wires and field shaping wires strung perpendicular to the radial

direction. The detector is 2.8 m long in :: with an inner radius of 8 cm and an

outer radius of 22 cm. It covers a pseudorapidity range of lr1I < 3.5. The tracking

chambers use a 50o/c-50% mixture of ethane and argon gas. \\"hen charged particles

pass through the gas, they ionize the gas, and the freed electrons drift ( with a velocity

of 46pm/ns) in the a.xia.l direction to the sense wires. The voltage drop on the wire is

read out and amplified. The position of the wire provides radial information about the

particles traversing the detector and the drift time provides longitudinal information,

18

=~ /' _ / /' j /±_K9 %~=X/X~? X? /'j 0*C % _?j K_? >j Wj/j±— X?jW h 8=X?J /'X= X?!~±— _/X~?

!±~— — ^/X% j /±_K9=* /'j % ± X— _±° ;j±/j] X= ~K_/jWh 4 'j ~K_/X~? ~ ! /' j %±X— _±°

•• X? /j ±_K /X~? ;j±/j] X= W j /j ±— X? j W [X/' m — — ^?Kj±/_ X? /° X? x K_ ± /~ ~ ? ~! _

K'_±JjW %_ ±/ XK j %_==X?J /' ±~ ^ J ' /'j 2 45 X= ='~[? X? B XJ^±j nhr

(2Y(2^<0—1 •q0N<5]—

50q5v

*Y„m2*Y„m2 b*^x„m2

^<0—n

BXJ^±j nhre 11 'j? _ K'_±JjW %_±/XKj %oX==j= /'±~^J' /'j 245* /'j J_= X= X~?X\jWh 4'j !±jjW jjK/±~?= W±X!/ /~ /'j =j?=j [X±j= ='~[?h B±~— !7h

nhahmhn g j ? /±_ 4±_K9X?J g ' _ — > j ± Tg4g'

4'j g j ? /±_ 4±_K9X?J g ' _ — > j ± X= _ _±Jj K°X?W±XK_ W±X!/ K'_— >j± /' _ / =^ ±±~^?W=

/'j 145h v/ X= nha — ~?J T_~?J C{ _? W '_= _? X??j± ±_W X^= ~ ! shn ±^ _ ? W _ ? ~^ /j±

±_WX^= ~! mhnt X?h v/ %±~;XWj= !^ nE, /±_K9 ±jK~?=/±^K/X~? X? /' j %=j^W~±_%XW X/° ±_?Jj

Q*Q d ^ X h

4 'j g 4 g K~?=X=/= ~! tu _°j±= ~ ! us • S J~WE%_/jW /^ ? J = /j ? [X±j= ±^ ?? X?J /'j

j?J/' ~! /'j K'_— >j±h 4'j° _ ±j J ±~^%jW X?/~ ?X?j N=^%j±E_°j±=hN 4'j±j _±j !X;j q€<q]

=^%j±_°j±= X? ['XK' /'j [X±j= ±^? %_±_j /~ /'j >j_— _?W !~^± 1N—0—£ =^%j±_°j±= X?

['XK' /'j [X±j= _±j ~!!=j/ >° „ n“ !±~— /'j >j_— X?jh v? /'j _]X_ =^%j±_°j±=* /'j±j

_±j FE [X±j= %j ± _°j± ['j±j_= X? /' j =/j±j~ =^%j±_°j±= /'j±j _±j V [X±j= %j ± _°j±h

g~— >X?X?J / ±_K9 X?J X?!~±— _/X~? %±~;XWjW >° /'j _]X_ =^%j±_;j±=h ['XK' — j_=^±j

/±_K9= X? /' j 0 * C %_?j* _?W /' j =/j±j~ =^%j±_°j±=* ['XK' — j_=^ ±j /±_K9= X? /'j 0*0•

mb


so that the track position in the r-:: plane can be determined. Csing this information

from multiple tracks. the primary vertex is located. The location of the primary

pp interaction vertex is determined with l mm uncertainty in ::. .-\. cartoon of a

charged particle passing through the \"TX: is shown in Figure 3.6

anode

sense r:Jw~es

• • • • • • • • •

cathode

• • • • • :_,,,/

• • • • • • • •

particle track

/

anode

Fig11n1 3.6: \\"hen a charged particle passes through the \"TX. tlw ~a.-; is ionized. The fn~ed electrons drift tu the sense wires shown. From [l].

3.2. 1.:3 Central Tracking Chamber (CTC)

The Central Tracking Chamber is a large cylindrical drift chamber that surrounds

the \"TX. It is 3.2 rn long ( along :; ) and has an inner radius of 0.3 m and an outer

radius of 1.38 m. It provides full 3-0 track recon~truction in the pseudornpirii~y rangP

,,,, < 1.1.

The CTC consists of 8-1 layers of -10 µm gold-plated tungsten wires running the

length of the chamber. They are grouped into nine --super-layers.'' There are five axial

superlayers in which the wires run parallel to the beam and four stereo superlayers in

which the wires are offset by ±3° from the beamline. In the axial superlayers, there

are 12 wires per layer \vhereas in the stereo superlayers there are 6 \Vires per layer.

Combining tracking information provided by the axial superlayers. which measure

tracks in the r-:: plane, and the stereo superlayers, which measure tracks in the r-rp

19

%_?j* JX;j= !^ nE, /±_K9 ±jK~?=/±^K/X~?h x =K'j— _/XK W±_[X?J ~ ! _ g4g j ? W % _ /j X=

='~[? X? BXJ^±j nhph c

3W0c0D wVn

""h ~ ""ccu ss ? ^ ? v ,

aprshss — — s ,

BXJ^±j nhpe g4g j?W%_/jh B±~— DFV*

L~=X/X~?jW _ > ~ ^ / /'j =j?=j [X±j= _±j 'XJ' ;~/_Jj !XjW [X±j= ['XK' j=/_> X=' _

mncs 1 iK — jjK/±XK !XjWh 4'j X~? X\_/X~? — jW X^— X= _ — X]/^±j ~! ubhrR x±J~?h ubhrR

w /'_?j * _?W shtR w/'_?~h 4 ' j — _]X— ^— W ± X! / / X— j ~! /'j X~?X\_/X~? jjK/±~?= X=

tss ?=* —^K' ='~±/j ± /' _ ? /'j nhc * [ W ( >j/[jj? >^?K' K±~==X?J=h yjK_^=j ~! /'j K±~==jW

jjK/±XK _?W — _J?j/XK !XjW= X?=XWj /'j K'_— >j±* /'j X~?X\_/X~? jjK/±~?= W±X!/ /~ /'j

=j?=j [X±j= [X/' _ )~±j?/\ _?Jj ~ ! uc“ [X/' ±j=%jK / /~ /'j jjK/±XK !XjWh 4~ _KK~^?/

!~± /'X= _?Jj* /'j _°j±= ~! [X±j= _ ±j /X/jW uc“ ±j _ /X;j /~ /'j ±_WX_ WX±jK/X~?h x /±_K9

EO


plane. gives full 3-D track reconstruction .. -\ schematic drawing of a CTC endplatc is

shown in Figure 3. 7. 5

I 554 00 mm I.D I

_I

figure 3. ,: CTC endplate. From [l].

Positioned a.bout the sense wires are high voltage field wires which establish a

1350 \"jcm electric field. The ionization medium is a mixture of -l9.67c .-\rgon, -l9.67c

Ethane, and 0.8o/c Ethanol. The maximum drift time of the ionization electrons is

800 ns, much shorter than the 3.5 µs bet\veen bunch crossings. Because of the crossed

electric and magnetic fields inside the chamber, the ionization electrons drift to the

sense wires with a Lorentz angle of -15° with respect to the electric field. To account

for this angle, the layers of wires are tilted -15° relative to the radial direction . .-\. track

:20

X= ±jK~?=/±^K /jW >° !X//X?J _ 'jX] /~ /'j ' X/= X? /'j g 4 g h 4 ' j /±_?=;j±=j — ~— j?/^—

±j=~^/X~? ~! /'j g 4 g X=

# f OCOOE % ± Tk j 1 iK ' h Tnhu'LP

y° K~— >X?X?J /'j /±_K9X?J X?!~±—_/X~? !±~— /'j g 4 g [X/' /'_ / !±~— /'j Z15h

/'j /±_?=;j±=j — ~— j?/^— ±j=~^/X~? K_? >j X—%±~;jW /~

# f shssm %=ETk jCAiK' h Tnhc'LP

nhaha g _~±X— j/j±=

x!/j± %_==X?J /'±~^J' /'j /±_K9X?J =°=/j— * %_±/XKj= j— j±JX?J !±~— /'j X?/j±_K/X~?

%~X? / j? /j ± /'j K_~±X—j/j±=h 4 ' j g, B g _ ~±X— j/j± =°=/j— X= =j%_±_ /jW X?/~ /'±jj

— _X? W j /j K /~ ± ±jJX~?= _KK~±WX?J /~ /'jX± %=j^W~±_% XW X/° K~;j±_Jje /'j g j? /±_ h 6_

_ ? W L^J K_~±X—j/j±=h

n ha ha CF g j? /±_ _?W 6_ g_~±X— j/j±=

4'j g j? /±_ K_~±X—j/j± X= _ =_— %X?J K_~±X— j/j±h v/ X= ~?JX/^WX?_° =jJ—j?/jW

X? /~ _? j jK /±~— _J?j/XK =jK/X~? Tgw-' _?W _ '_W±~?XK =jK/X~? Tgqx'h 4 ' j jjK/±~E

— _J?j/XK =jK/X~? K~?=X=/= ~! _ /j ±?_ / X?J _°j±= ~! nhmpc — — /'XK9 L' _>=~±>j± %_/j=

_ ? W c — — /'XK9 ZgZ5Ent %~°=/°±j?j =K X? /X _ /~ ± % _ /j= * _ ? W /'j '_W±~?XK =jK/X~?

K~?=X=/= ~! _ /j ±? _ / X? J _°j±= ~ ! ahc K— /'XK9 =/jj _> =~ ±>j± %_/j= _?W mhs K— /'XK9

L- - x T%~ °— j/'° — j/'_K±° _ /j' =KX? /X_ /~± %_/j=h 4 ' j jjK/±~— _J?j/XK =jK/X~? X=

< m p x £~ T < Fxs' X? j?J/'* _?W /'j '_W±~?XK =jK/X~? X= /j?W X?J OCFF ^?X/=

~ ! PY. 4 ' j ±j _±j /[~ [_;jj?J/' ='X!/X?J [_;jJ^XWj= %j ± /~[j±* ~?j ~? j_K' =XWj X?

_\ X— ^/' h g ~??jK/jW /~ /'j j_K' [_;jJ^XWj X= _ %'~ /~— ^/X% Xj ± /^>j TL - 4 'h

EF


is reconstructed by fitting a helix to the hits in the CTC. The transverse momentum

resolution of the CTC is

;;j.{Jr - = 0.002 PT(Ge\"jc). PT

( 3.-l)

By combining the tracking information from the CTC with that from the S\"X.

the transverse momentum resolution can be improved to

_;ip,r . - = 0.001 p,r{Ge\ /c). ( :3_.j) PT

3.2.2 Calorimrters

.-\ftl'r passing through the tracking system. particles erm•rging from the intPraction

point entn the calorimeters. The CDF Calorinlf'ter systt>m is separated into thref~

main detector regions according; to tll(•ir psP11dorapidity l.'owrage: the Central. \\"all

and Plug calorimetf>rs.

3.2.2. l Central and Wall Calorimeters

The Central calorimeter is a sampling calorimeter. It is longitudinally segmPnted

into an electromagnetic section (CE~[) and a hadronic section (CH.-\). The electro

magnetic section consists of alternating la~·ers of :3.175 mm thick Ph :1hsorber plates

and 5 mm thick SCSX-38 polystyrene scintillator plates, and the hadronic section

consists of alternating layers of 2.5 cm thick steel absorber plates and 1.0 cm thick

P1nL-\ (polymethylmethacrylate) scintillator plates. The electromagnetic section is

-17.\"0 (- L\0 ) in length, and the hadronic section is --L 7 ,\0 in length. Both sections

are divided into 2-L 15° wedges in 9 . . -\ diagram of one o wedge is shown in figure 3.8.

Each wedge is divided into 10 projective towers in,,, each tower subtending 0.11 units

of T/. There are two wavelength shifting waveguides per tower, one on each side in

azimuth. Connected to the each waveguide is a photomultiplier tube (PMT).

21

wu

)j!/

6_;j Z^/j± A Z'jj/=

BXJ^±j nhte x mcn s3 [jWJj ~! /'j gj?/±_ K_~±X—j/j±h B±~— D7h

4 ' j gj? /±_ K _ ~ ± X— j /j ± j]/j?W= ahc ±? %_±_j /~ /'j >j_— X?j ~? jX/'j± =XWj ~!

C f O _ ? W K~;j±= _ % =j^W~ ±_% XW X/° ±_?Jj ~! ’±i’ d FhF h 4 ' j WX=/_?Kj !±~— /'j X? /j±_K /X~?

% ~ X? / /~ /' j X??j± ± _ W X^ = ~! /'j K_ ~ ± X— j/j ± X= < mpn K—h

x = Wj=K±X>jW X? ZjK /X~?= uhc _ ? W uhrh ['j? _ % _ ± / XK j 'X/= /' j K_~±X—j/j±* X/ %±~E

W^Kj= _ ='~[j±h 6 ' j ? _ K'_±JjW % _ ±/ XK j !±~— /'j ='~[ j± %_==j= /' ±~^J' _ =K X? /X _ /E

X?J % _ /j * X/ >±X?J= _ =K X? /X _ / X?J — ~jK^j X?/~ _? j]K X/jW =/_ /j h 6 'j? /'j —~jK^j

±j_]j= >_K9 /~ X/= ~ ± XJ X? _ =/_ /j * X/ X=~/±~%XK_° j — X/= XJ'/* ^=^_° X? /'j ^ /±_; X~ j/

±_?Jjh Z~— j ~! /'j XJ' / j— X//jW X= /'j? /±_%%jW X? /' j =K X? /X _ /X?J %_/j _?W X= X?E

EE


Lead Sc:nnllator Saricwich ---+-~

X

Figure :3.8: A 15~ ¢> wedge of the Central calorimeter. From [lj.

The Central calorimeter extends 2.5 rn parallel to the bcamline on either side of

z = 0 and covers a pseudorapi<lity range of lril <1.1. The distance from the interaction

point to the inner radius of the calorimeter is "' 17:3 cm .

. ..\s described in Sections -!.5 an<l -1.6, when a particle hits the calorimeter. it pro

duces a shower. \\"hen a charged particle from the shower passes through a scintillat

ing plate, it brings a scintillating molecule into an excited state. \\'hen the molecule

relcLxes back to its original state, it isotropically emits light, usually in the ultraviolet

range. Some of the light emitted is then trapped in the scintillating plate and is in-

22

/j±?_° ±j!jK/jW /~ /'j jWJj ~! /'j %_/jh 4'j /[~ [_;jj?J/' =' X! / X?J [_;jJ^XWj= _ /

/'j jWJj= ~ ! /'j %_/j= X? ~h _>=~±> /'j ^/±_;X~j/ XJ'/ _?W ±jj— X/J±jj? XJ'/h Z~—j

~! /'j J±jj? XJ'/ /'j? /±_;j= ±_WX_° ~^/[_±W /~[ _±W /'j j?W ~! /' j [_;jJ^XWj /~ _

L- 4h

4'j 6 _ K_~±X— j/j± K~;j±= _? _[9[_±W Jj~— j/±XK_ ±jJX~? T=jj B XJ^±j hnhn' >jE

/[jj? /'j g j? /±_ K_ ~±X— j/j± _?W /'j L ^J K_ ~±X— j/j± h v/ K~?=X=/= ~ ! nhm K— /'XK9

=/jj _> =~ ±> j ± %_/j= _ /j ±?_ /jW [X/' FCO K— /'XK9 L - - x =K X? /X _ /~ ± %_/j=* _?W

K~;j±= _ ±jJX~? X? %=j^W~±_%XW X/° !±~— < OCVV d ’ii’ Fh Fh

nhE hECE L ^ J g _~±X— j/j±

4'j L ^J K_~±X— j/j± ^=j= J_= % ±~%~±/X~?_ /^ > j _±±_°= X?=/j_W ~! %_=/XK =KX?/XE

_/X?J % _ /j= _= X/= _K/X;j —jWX^—h v? /'j j jK /±~— _J?j/XK =jK/X~?* /'j nu _°j±= ~!

% ±~%~±/X~?_ /^>j= _±j X?/j±j_;jW [X/' ahp —— /' XK9 _°j±= ~! L>h v? /'j '_W±~?XK

=jK/X~?h as _°j±= ~! %±~%~±/X~?_ /^>j= _±j X?/j±j_;jW [X/' nhm K— /'XK9 =/jj _>E

=~±>j± % _ /j= h 4'j =jJ— j?/_/X~? !~± /'j j jK /±~— _J?j/XK _?W '_W±~?XK =jK/X~?= X= /'j

=_—j* ? _— j° shsb X? ii _?W c“ X? ~h

g'_±Jj %±~W^KjW >° X~?X\X?J %_±/XKj= /±_;j±=X?J /' j J_= X? /'j % ±~%~±/X~?_ /^>j=

X= X? /j±?_° _—%X!XjWh 4 'j j]/j?/ ~ ! /'X= _—%X!XK_/X~?* ['XK' W X±jK /° _!!jK/= /'j

±jK~?=/±^K/jW j?j±J° ~! ='~[j± %_±/XKj=* X= *^X/j =j?=X/X;j /~ /'j /j— % j±_ /^ ±j _?W

%±j==^±j ~! /' j J_=h B~± /' X= ±j_=~?* J_=j~^= K_~±X— j/j±= ±j*^X±j _ = ^ > = /_ ? / X_ _— ~^?/

~! — ~?X/~±X?Jh v? _WWX/X~?* J_=j~^= K_~±X— j/j±= '_;j _ ;j±° =—_ =_— % X?J !±_K/X~?

_?W ?~ = _ /^ ± _ / X~ ? j!!jK/= Dc7h 4'X= JX;j= ±X=j /~ /'j N4j]_= /~[j±B= j!!jK/* =X?Jj /~[j±=

[X/' =XJ?_= ~±Wj±= ~! — _J? X/^Wj _±Jj± /' _ ? /'~=j X? ?jXJ'>~±X?J /~[j±=h B~± /'j=j

±j_=~?=* /' j L ^ J K_~±X— j/j± [_= ±j%_KjW >° _ =K X? / X _ /~ ± >_=jW K_ ~ ±X— j/j± X? 0^?

vvh 4'j ?j[♦ K_ ~ ±X— j/j± X= Wj=K±X>jW X? Wj/_ X X? g ' _ % /j ± ch

an


,

terually reflected to the edge of the plate. The two wavelength shifting waveguides at

the edges of the plates in o. absorb the ultraviolet light and reemitgreen light. Some

of the green light then trawls radially outward toward the end of the waveguide to a

P~IT.

The \Vall calorimeter covers an awk,..,·ard geometrical region (see Figure 3.3) be

tween the Central calorimeter and the Plug calorimeter. It consists of 5.1 cm thick

steel absorber plates alternated with 1.0 cm thick P~L\I.-\ scintillator plates. and

cowrs a region in psendorapidity from "" 0.66 < !11/ <"' 1. 1.

:3.2.2.2 Plug Calorimeter

The Plug calorimeter uses gas proportional tube arrays instead of plastic scintil

lating plates as its actiw medium. In the electromagnetic SPction. die :J..l layers of

proport~onal tubes are iuterleave<l with 2.7 mm thick layers of Pb. In the hadronic

section. 20 layers of proportional tubes are interlem·ed with 5.1 cm thick steel ab

sorber plates. The segmentation for the electromagnetic and hadronic sections is the

same, namely 0.09 in 1/ and 5° in o.

Charge produced by ionizing pt~rtides traversing the g,'....'> l!! ~he proportional tubes

is internally amplified. The extent of this amplification, which directly affects the

reconstructed energy of shower particles. is quite sensitive to the temperature an<l

pressure of the gas. For this reason. gaseous calorimeters require a substantial amount

of monitoring. In addition. gaseous calorimeters have a very small sampling fraction

and no saturation effects [5]. This gives rise to the ·'Texas tower'' effect. single towers

with signals orders of magnitude larger than those in neighboring towers. For these

reasons, the Plug calorimeter was replaced by a scintilla.tor based calorimeter in Run

II. The new calorimeter is described in detail in Chapter 5.

nhahn -^~? , j/jK /~ ±

6 'j±j_= _ ~ /' j ± %_±/XKj= Tj]Kj%/ ?j^/±X?~=' ='~[j± _ ? W _±j /'^= K~— %j/j°

_>=~±>jW X? /' j K_~±X— j/j±* —^~?= Jj?j±_° W~ ?~/ ='~[j± X? /' j K_~±X— j/j±h 4~ !X±=/

~±Wj±* /'j° _ ±j = X— %° — X? X— ^— X~?X\X?J X? /' j K_~±X— j/j±h x?° %_±/XKj= Wj/jK/jW

±_WX_° >j°~?W /'j K_~±X— j/j±= /'j? * K_? >j _==^— jW /~ >j —^~?=h 4 'j±j _±j /'±jj

K~—%~?j?/= ~ ! /'j — ^~? =°=/j— _ / g , B T=jj B XJ^±j nhn'e /'j g j? /±_ -^~? g '_— >j±=

Tg- 8'h /'j g j? /±_ - ^~? 8%J±_Wj Tg- L'* _?W /'j gj?/±_ - ^~? w]/j?=X~? Tg-5'h

x /'±jj K~— %~?j? /= K~?=X=/ ~! =X?JjE[X±j* ±jK /_?J^ _± W±X! / /^>j=h

nhahn CF g j? /±_ - ^~? g '_— >j±= Tg-g'

4'j g-8 X= ~K_/jW ±_WX_° ~^/=XWj /'j g j? /±_ q_W±~? g _ ~±X— j/j± _ / _ WX=/_?Kj

~! nhup — !±~— /'j >j_— X?j _?W K~;j±X?J _ %=j^W~±_%XW X/° ±_?Jj ~! >i7 d shrh v/ X=

=jJ—j?/jW X? /~ auh mahr“ [jWJj= X? ~h ZX?Kj /' j ±j _±j ahu“ J_%= >j/[jj? /'j [jWJj=*

/'j g-8 K~;j±_Jj X? £ X= ~?° tcRh w_K' g - 8 [jWJj K~? /_ X?= /'±jj /~[j±= [X/'

j_K' /~[j± K~? /_ X? X?J !~^± ±_WX_ _°j±= ~! !~^± W±X! / /^>j=h 4 ' j _°j±= _±j ~!!=j/ !±~—

~?j _?~/'j± >° << E — — /~ ±j—~;j _—>XJ^X/° ~ ! ['XK' =XWj /'j %_±/XKj %_==jW /'j

* [X±j= X? ~h 4 ' j %~=X/X~? ±j=~^/X~? ~ ! /'j g- 8 X= acs : <S X? ~ _?W mha — — X? <h

nhahn CE g j? /±_ - ^~? 8%J±_Wj Tg - L'

4'j gj?/±_ q _W±~? g _~±X— j/j± X= /~~ ='~±/ /~ !^° ~?JX/^WX?_° K~? /_ X? 'XJ'

j?j±J° '_W±~? ='~[j±=h 6 'j? /'j —^~? =°=/j— K~?=X=/jW ~ ! ~? ° /'j g-8h /'j /_X=

~! 'XJ' j?j±J° ' _ W ±~ ? ='~[j±= [~^W ~!/j? j_9 ~ ^ / /'j >_K9 ~ ! /'j gqx _ ? W %±~W^Kj

_ =XJ?_ X? /'j g - 8 h /'^= !_9X?J _ —^~?h v? ~ ±Wj± /~ _;~XW =^K' =XJ?_=* _?~ /'j ±

shr —— ~! =/jj Tahu xs' [_= _WWjW _ / /'j >_K9 ~ ! /'j gqxh y j'X?W /'j _WWjW =/jj*

!~^± —~±j _°j±= ~ ! W±X! / K'_— >j±= [j±j _WWjW _ ? W ?_—jW /'j g j? /±_ -^~? 8%J±_Wj

Tg - L'h 4'j g - L !X= X? /'j J_%= >j/[jj? [jWJj= X? =/3 X? /' j g-8h x/ /' j X??j±

_?W ~^/j± =^±!_Kj= ~! /' j g-Lh /'j±j _±j =K X? /X _ /~ ± %_?j= Tg ZL' ^=jW /~ %±~;XWj

au


3.2.3 .\[uon OPtector

\\"hereas all other partides (except neutrinos) shower and are thus completely

absorbed in the calorimeter. muons generally do not shower in the calorimeter. To first

order. they are simply minimum ionizing in the calorimeter . .-\ny particles detected

radially beyond the calorimeters then. can be assumed to be muons. There are three

components of the muon system at CDF (see Figure 3.3): the Central .\[uon Chambers

(C.\[C). thr Central .\Iuon Cpgrade (C.\[P). and the Central .\Iuon Extension (C.\[X) .

.-\ll three components consist of single-wire. rPctangnlar drift tubes.

3.2.3.1 Central .\Iuon Chambers (C.\[C)

The C.\[C is located radially outsiclt> thP Ct->ntral Hadron Calorimeter at a distance

of :3.-t, Ill from the beamlinP and co\·Pring a psf'l1dorapidity range of Jr1i < 0.6. It is

sPgm,•ntPd into 2-L 12.6° wedges in o. Sinc1! there an• 2.-l' gaps between thP wPdges.

the C.\Il" coverage in o is only 85%. Each C.\IC wedge contains three towers with

each tower containing four radial layers of four drift tubes. Thi:' layers are offset from

one another by --.. 2 mm to remove ambiguity of whid1 sick tlw particle passed thP

, wires in o. The position resolution of the C.\IC is 250 /Hn in o and 1.:2 mm in .:.

3.2.3.2 Ce[ltr,1,I .\Iuon Cpgrade (C.\IP)

The Central Hadron Calorimeter is too short to fully longitudinally contain high

energy hadron showers. \\.hen the muon system consisted of only the C.\[C, the tails

of high energy hadron showers would often leak out the back of the CH . .\ and produce

a signal in the C.\IL", thus faking a muon. In order to avoid such signals. another

0.6 mm of steel (2.-t ,\0 ) was added at the back of the CH . .\. Behind the added steel.

four more layers of drift chambers were added and named the Central .\[uon Cpgrade

(C.MP). The C.\.IP fills in the gaps between wedges in ¢ in the C~IC .. .\t the inner

and outer surfaces of the C\lP. there are scintillator planes (CSP) used to provide

24

/ X— X?J X?!~±— _/X~?h

nhahnhn g j? /±_ -^~? w] /j?=X~? Tg-5'

x/ /'j / X— j /'j g - L [_= _ WWjW * _?~ /'j± —^~? =°=/j— * /'j g j?/±_ - ^~? w]/j?E

= X~? Tg-5' [_= _WWjW X? ~ ±W j ± /~ j]/j?W /'j —^~? =°=/j— A= K~;j±_Jj X? %=j^W~±_%X/°

X? /'j O hV d Q0$Q d FCO ±_?Jjh z ^ = / _= X? /'j g- Lh /'j X??j± _?W ~^ /j± =^±!_Kj= ~! /'j

g - 5 '_;j =K X? /X _ /~± %_?j=* 9?~[? _= /'j gZ5h


timing information.

3.2.3.3 Central :\Iuon Extension (C:\IX)

.--\t the time the C:\IP was added, another muon system, the Central :\Iuon Exten

sion (C:\IX) was added in order to extend the muon system's coverage in pseudorapity

in the 0.6< / q/ < 1.0 range . .Just as in the C\[P. the inner and outer surfaces of the

C:\IX have scintillator planes. known as the CSX.

25

g q x L 4 w 0 u

g x )Q 0 v- w40 2

4 ' j =^>Wj /jK /~ ± =°=/j— ['XK' X= K ±^KX_ /~ /'j _?_ °= X= WX=K^==jW X? g ' _ % /j ± p X=

/'j K_ ~ ±X— j/j± h qj±j* [j JX;j _ >±Xj! = ^ — — _ ±° ~! /' j >_=XK= ~! K_ ~±X— j/±° h B~± _

K~— %j /j WX=K^==X~?* /'j ±j_W j ± X= ±j!j±±jW /~ 0j!j±j?Kj DV Vh

uhm 6 '_/ K_~±X— j/j±= — j_=^ ±j

v? _ /°%XK_ — ^/XK~— %~?j?/ Wj/jK/~± =^K' _= /'_ / W j=K ± X>jW X? ZjK/X~? nhah K_~±X—jE

/j±= _ ±j ~K_/jW 7^=/ ~^/=XWj /'j /±_K9X?J =° = /j— _?W _ ±j = X— % ° _ _±Jj K'^?9 ~! Wj?=j

— _/j±X_ h 6 'j? %_±/XKj= j— j±JX?J !±~— /' j X?/j±_K/X~? D7~X?/ 'X/ /'j — _/j±X_ * /'j°

_±j K~— %j/j ° _>=~±>jW T_?W h j]Kj%/ !~± ±?^~?= _?W ? j ^ /± X?~= * _?. /' ^ = Wj=/±~°jW

!~± !^ ± /' j ± —j_=^±j— j?/ %^±%~=j='h v? /'j _>=~±% /X~? %±~Kj==* Kj±/_X? — _/j±X_ = X?

/'j K_ ~ ± X— j/j ± %±~W^Kj _ = XJ?_ /'_/ K_? >j —j_=^±jWh B ±~— /'j =XJ?_= /' _ / ±j=^/*

/'j j?j±J° ~! /'j %_±/XKj= K_? >j WjW^KjWh 6'Xj /'X= X= /' j —_X? %^±%~=j K_~±X—jE

/j±= =j±;j* /' ±~^J' =jJ— j?/_/X~? * /'j° _=~ ~!/j? _±j ^=jW /~ WX=/X?J^X=' j ♦=h 1= _?W

<“A= !±~— K'_±JjW '_W±~?= _ ? W /~ — j_=^±j /'j %~=X/X~? _ ? W _?J^_± W X= /± X>^ /X~?= ~!

%_±/XKj=* %_±/XK^_±° 7j/=h

uha L_±/= ~ ! _ K_~±X— j/j±

g _ ~ ±X— j/j±= K~?=X=/ ~ ! /' ±jj —_X? % _ ± /= * /'j q5N<_— S qN—0<q ]■ /'j •q11<_— SqN—0<q]

T~± q91£09—0{■ _?W /'j 0—q%£RNB

6 ' j? _ K'_±JjW %_±/XKj %_==j= /'±~^J' /' j _K/X;j — _ /j ± X_ * X/ Jj?j±_/j= _ =XJ?_h

- _/j±X_ = /' _ / '_;j >jj? ^=jW _= _K/X;j — _/j ± X_ X? — ^ / X% ^ ±% ~ =j Wj/jK /~±= _ / _KKjE

j ±_ /~ ±= X?K^Wj =KX?/X_/X?J %_=/XK * *^_±/\ * X*^XW _±J~?* !_?K° K±°=/_=* _ ? W ;_±X~^=

/°%j= ~ ! J_= —X]/^±j=h 6 'j? _ K'_±JjW %_ ± / XK j %_==j= / ' ±~ ^ J ' =KX?/X _ /X?J —_/j±X_*

—~jK^j= X? /'j — _/j±X_ _ ±j >±~^J'/ X?/~ _? j]KX/jW = /_ / j h 6 'j? /'j° ±j_] >_K9

ar


CH . ..\PTER -1

C . ..\LORI.\IETRY

The subdetector system which is crucial to the analysis discussed in Chapter 7 is

the calorimeter. Here, we gi,·e a brief summary of the basics of calorimetry. For a

complete discussion. the reader is referred to Reference [6].

-L 1 \\"hat calorimeters measure

In a typical multicomponent detPrtor such as that clt•scribed in Section 3.2. calorime

ters are located just outside the tracking system and are simply a large chunk of dense

material. \\"hen particles emerging from the intnaction point hit the material. they

are completC'ly absorlwd (and. except for muons and neutrinos. an• thus destroyed

for further IllPi.L-;urPmt'nt purposes). In tlw absorption process. n•rtain materials in

tlw calorimeter prod11cP a signal that can lw IllPasun·d. From thP signals that result.

the energy of the particlc•s can Le dedun•d. \\"bile this is the main purpose calorime

ters serve. through segmentation. they also often are used to distinguish e ·s, ~, ·s and

, ii0 ·s from charged hadrons and to measure the p1)sition and angular distributions of

particles. particularly jets.

-1.2 Parts of a calorimeter

Calorimeters consist of three main parts. the active material. the pas.-;iue material

(or ab::;orber), and the readout.

\\"hen a charged particle passes through the active material. it grnerates a signal.

.\faterials that have been used as active material in multipurµose detectors at accel

erators include scintillating pl,L'>tic. quartz, liquid argon. fancy crystals, and various

types of g,L'-i mixtures. \\'hen a charged particle passes through scintillating material.

molecules in the material a.re brought into an excited state. \\"hen they relax back

26

/~ /' j X± J ±~^?W = /_ /j * /'j° j—X/ XJ'/* ^=^_° X? /' j >^j ~± ^ /±_; X~ j/ ±_?Jjh 4'X=

XJ'/ X= K~jK/jW _?W — j_=^±jWh 6 'j? * ^ _ ± /\ X= ^=jW _= _? _K/X;j — _/j ±X_ * _ =XJ?_ X=

Jj?j±_ /jW W ^ j /~ /'j g♦j±j?9~; — jK'_?X=— * ?_—j° XJ'/ X= %±~W^KjW ['j? _ %_±/XKj

/±_;j= /' ±~^J' _ — jWX^— !_=/j± /' _ ? /' j =%jjW ~ ! XJ'/ X? /'_ / — jW X^— h 6 'j? J_=

~± ?~>j X*^XW= Tx±h (±h 5j' _±j ^=jW _= /'j _K/X;j — jWX^— * X~? X\_/X~? X= /' j —j_?=

/' ±~^J' ['XK' _ =XJ?_ X= %±~W^KjWh 6 'j? _ K'_±JjW %_±/XKj %_==j= /' ±~^J' /'j

— jWX^— * /'j —jWX^— X= X~?X\%W _?W /'j X~?X\_/X~? K'_±Jj= _±j K~jK/jW ~± X?W^Kj _

=XJ?_ X? _? jjK/±~Wj %_KjW X? /'j — jW X^— h

4 ' j %_==X;j — _/j±X_ X= ^=^_° _ Wj?=j — _/j±X_ ['XK' K_^=j= _ %_±/XK j /~ ='~[j±

_?W j;j? /^_ ° K~—%j/j° _>=~±>= /' j %_±/XKjh L ~%^ _ ± K'~XKj= !~± /'j _>=~±>j±

— _/j ±X_ X?K^Wj L'h =/jj T Bj'h E-A= C _ ? W !_?K° K±°=/_ = =^K' _= /'_ X^— EW~%jW Kj=X^—

X~WXWj ~ ± j_W /^?J=/_ /j TL > 6 Q ’' h

4 ' j ±j_W~^ / K~?=X=/= ~! /'j =°=/j— ['XK' / ±_? =% ~ ±/= /'j =XJ?_= % ±~W^KjW X?=XWj

/'j _K /X;j — _/j±X_ /~ _ — ~±j K~?;j?Xj?/ ~K_/X~? ~^ /= XWj ~! /'j — _/j ±X_ ['j±j ~/'j±

X? = /±^ — j? /= _?W jjK/±~?XK= /'_/ K_? —joX=^±j _?W %±~Kj== /'j =XJ?_ _±j ~K_/jWh

6 _;jJ^XWj= ~ ± [_;jj?J/' ='X!/X?J — _/j ± X_ _?W L - 4 = _±j ~!/j? ^=jW /~ / ±_? =%~ ±/

GG _?W — j_=^ ±j /'j =XJ?_* ±j=%jK/X;j°* X? XJ'/ >»X=jW K_~±X—j/j±=h v? X~?X\_/X~? >_=jW

K_~±X— j/j±=* jjK/±~Wj= _±j ^=jW /~ K~jK/ K'_±Jjh

uhn 4°%j= ~ ! K_~±X— j/j±=

4 ' j ±j _ ±j /[~ —_X? /°%j= ~! K_~±X— j/j±=e 1qS•]<*4 _?W >£S£4—*—£R1B v? _ =_—E

%X?J K_ ~ ± X— j/j ± * /'j _K/X;j —jWX^— X= _ WX!!j±j?/ — _ /j ± X_ /'_? /' j %_==X;j —jWX^—

_?W X= =~— j'~[ X?/j±=%j±=jW [X/'X? /'j _>=~±>j±h ZX?Kj _ =XJ?_ X= % ±~W^KjW ~?° X?

/'j _K /X;j — jWX^— * /'j K_~±X— j/j± £=_— % j= ♦A /'j j?j±J° Wj%~=X/X~? ~! /'j X?K~—X?J

%_±/ XK j A= ='~[j±h Q?j /°%j ~! =_— %X?J K_~±X— j/j± K~?=X=/= ~! _ /j ±? _ / X? J %_?j= ~!

_>=~ ±>j± _ ? W _K/X;j — jWX^— * =^K' _= =K X? /X _ /X?J % _ /j= ~± X*^XW _ ±J~? _ /j ±?_ /jW

[X/' % _ /j = ~! °~^± !_;~±X/j _>=~±>j± T=/jj ~± L>h !~± j]_—%j'h v? ~ /'j± Wj=XJ?=h

ap


to their ground state, they emit light. usually in the bluP or ultraviolet range. This

light is collected and measured. \\"hen quartz is used as an active material. a signal is

generated due to the C'erenkov mechanism. namely light is produced when a particle

travels through a medium faster than the speed of light in that medium. \Vhen gas

or noble liquids (Ar. Kr. Xe) are used as the active medium. ionization is the means

through which a signal is produced. \\.hen a charged particle pa.sses through the

medium. the medium is ionizPd and the ionization charges are collected or induce a

signal in an electrode placed in the medium.

The passive material is usually a dense mat£'rial which rauses a particle to shower

and eventually completely absorbs the partidt·. Popular choices fur the absorber

material include Pb. stt>d (Fe). :!:I~ L". an<l fancy rrystals such as thallium-do1wd cesium

iodidt! or lead tungstate (Pb\\"Oi).

The readout consists of the system which ~ransports the signals producrd insidt>

the actin! material to a mort• conveniPnt lo<'ation cmtsidP of thf' material when• otlll'r

instruments and electronics that can measure and process the signal are located.

\\"avcguides or wm·elength shifting material and P:\ITs an~ often used to transport

, and measure the signal. respectively. in light basPd calorimeters. In ionization based

calorimeters. electrodes are use<l to collect charge.

-L3 Types of calorimeters

There are two main types of calorimeters: .rnmpling and homogeneotls. In a sam

pling calorimeter, the active medium is a different material than the passive medium

and is somehow interspersed within the absorber. Since a. signal is produced only in

the active medium. the calorimeter '"samples·· the energy deposition of the incoming

particle"s shower. One type of sampling calorimeter consists of alternating planes of

absorber and active medium. such as scintillating plates or liquid argon alternated

with plates of your favorite absorber (steel or Pb, for example). In other designs,

X?/j±j_;jW /' ±~ ^ J ' ~ ^ / /'j _>=~ ±>j± = /±^ K /^ ±j _ ±j =KX?/X_/X?J ~ ± *^_±/\ !X>j±=h

v? _ '~— ~Jj?j~^= K_~±X—j/j±* /'j _K/X;j _ ? W %_==X;j —jWX_ _ ±j ~?j _?W /'j =_— j

— _/j±X_ h g ±°=/_ = _ ? W j_WiJ_== _±j /'j — ~=/ K~— — ~? — _/j±X_ = ^=jW X? _ '~— ~E

Jj?j~^= K_ ~ ± X— j/j± X? _±Jj '°>±XW Wj/jK /~±= _ / ' XJ' j?j±J° %_±/ XK j _KKjj±_/~±=h v?

K~=—XK ±_° j]%j±X— j?/= * /'j _ X± ~ ! /'j _ /— ~=%'j±j * /'j [_/j± ~! ~Kj_?=* ~± /'j XKj ~!

/'j x?/_±K/XK _K / _= _ '~—~Jj?j~^= K_~±X— j/j±* >~ /' %±~W^KX?J _ — j_=^±_>j =XJ?_

_?W _>=~±>X?J /'j K~=—XK ±_°=h

uhEm Z jJ— j?/_ /X~?

g_~±X— j/j±= _ ±j ~!/j? N=jJ—j?/jWN X?/~ ]qN—0q] 1—5N<£*1 _?W ]£*4<NR%<*q] 1—5N<£*1B

ZjJ— j?/_/X~? = X— % ° —j_?= /' _ / /'j =XJ?_ !±~— _ %_±/XK^_± %'°=XK_ ±jJX~? ~! /'j

K_ ~±X— j/j± X= ±j_W ~ ^ / =j%_±_/j° !±~— ~ /'j± %'°=XK_ ±jJX~?=h )_/j±_ =jJ— j?/_/X~?

^=^_° ±j!j±= /~ /' j =jJ— j?/_/X~? ~! /'j K_ ~ ± X— j/j± X?/~ /~[j±= ~ ! PO _?W ~h 4°%XK_°*

/'j /~[j± = /±^ K /^ ±j X= %±~7jK/X;j* — j_?X?J /'j K±~== =jK/X~?_ _ ±j _ ~! /'j /~[j± Jj/=

_±Jj± _= _ !^?K/X~? ~! /'j WX=/_?Kj !±~— /'j X? /j ±_K / X~? %~X?/h )_/j±_ =jJ— j?/_/X~?

JX;j= _ —j_?= ~! — j_=^±X?J /'j % ±~W^K/X~? _?Jj ~! /'j %_±/XKj= Wj /jK /jW _?W ±j=~;E

X?J ='~[j±= !±~— =j;j±_ %_±/XKj= /±_;j±=X?J /' j =_ — j %'°=XK_ _±j_ h 4'j %±jKX=X~?

[X/' ['XK' /'j % ±~ W ^ K / X~ ? _?Jj ~ ! %_±/XKj= K_? >j — j_=^±jW Wj%j?W= ?~/ ~?° ~? /'j

J±_?^ _±X /° ~! /'j _ /j ±_ =jJ— j?/_/X~? >^/ /'j %'°=XK_ =X\j ~! /'j ='~[j±= X?W^KjW >°

/'j %_±/XKj= X? /' j K_~±X— j/j±h 4°%XK_ _/j±_ =jJ— j?/_/X~? X?;~;j= /~[j±= [ X/' _

=X\j ~ ! <s hm ^?X/= ~ ! 0~ _?W < m c & ~! ~h 4' X= ±j=^/= X? =j;j±_ '^?W±jW Tlcss' =j%_±_ /j

/~[j±= ~! _/j±_ =jJ— j?/_ /X~? h

)~?JX/^WX?_ =jJ— j? /_ / X~? ±j!j±= /~ =jJ— j? /_ / X~? _~?J /'j W X±jK/X~? /±_;jjW >°

%_±/XKj= !±~— /'j X? /j±_K /X~? %~X?/h 4 'j±j _±j — _ ? ° !j[j± ~?JX/^WX?_ =jJ— j?/_/X~?=

/' _ ? _/j±_ ~?j=h 1j±° ~!/j?* X? !_K/* /'j±j _ ±j ~?° /[~ ~?JX/^WX?_ =jJ—j?/=*

±j!j±±jW /~ _= /'j NjjK/±~— _J?j/XK♦A _?W N'_W±~? XK ♦♦ =jK/X~?=h 4 ' j jjK/±~— _J?j/XK

=jK /X~? A= —_X? % ^ ±%~=j X= /~ — j_=^±j /'j j?j±J° ~ ! jjK/±~?= _? W %'~/~?=h ZX?Kj

at


interlea\·ed throughout the absorber structure are scintillating or quartz fibers.

In a homogeneous calorimeter. the active and passive media are one and the same

material. Crystals and lead/ glass are the most common materials used in a homo

geneous calorimeter in large hybrid detectors at high energy particle accelerators. In

cosmic ray experiments. the air of the atmosphere. the water of oceans, or the ice of

the Antarctic act as a homogeneous calorimeter. both producing a measurable signal

and absorbing the cosmic rays.

-1.-l Segmeutation

Calorimeters are often ··segmented .. into latt:.ral :;ections and longitudinal .,ection.,.

Segmentation simply means that the signal from a particular physical region of the

calorimeter is n 1ad ont separately from other physical regions. Lateral segmentation

usually refers to the segmentation of the calorimeter into towers of 17 and o. Typically.

the town structure is projectin.•. meaning the cross sectional area of the tower gets

larger as a function of the distancP from the interaction point. Lateral segmentation

gives a means of measuring the production angle of the particles detected and resoh·

ing showers from se\·eral particles traversing the same physit:al area. The precision

with which the production angh'! of particles can lw measured depends not only on the

granularity of the lateral segmentation but the physil'al sizP of the showers induced by

the particles in the calorimeter. Typical lateral segmentation invoh·es towPrs with a

size of -0.1 units of,, and -15' of o. This results in several hundred (>500) separate

towers of lateral segmentation.

Longitudinal segmentation refers to segmentation along the direction travelled by

particles from the interaction point. There are many fewer longitudinal segmentations

than lateral ones. Very often. in fact. there are only two longitudinal segments,

referred to as the '·electromagnetic'· and ·'ha.clronic"' sections. The electromagnetic

section ·s ma.in purpose is to measure the energy of electrons and photons. Since

28

jjK/±~?= _ ? W %'~ /~?= _±j _>=~±>jW X? _ ±j_/X;j° =— _ _ — ~ ^ ? / ~! — _ /j ± X_ T=jj

ZjK/X~? u hc hm'h /'j j jK/±~— _J?j/XK =jK/X~? X= %_KjW X? ! ±~?/ ~ ! T_= =jj? >° %_±/XKj=

j—j±JX?J !±~— /'j X?/j±_K/X~? %~X?/' /'j '_W±~?XK =jK/X~? h 4'j '_W±~?XK =jK/X~?

K~—>X?jW [ X/' /'j j jK/±~— _J?j/XK =jK/X~? — j_=^±j= /'j j?j±J° ~! K'_±JjW '_W±~?=

['XK' ±j*^ X±j — ~±j — _/j±X_ /~ Wj%~=X/ /'jX± j?j±J°h

w jK/±~?= _?W %'~/~?= Wj%~=X/ /'jX± j?j±J° X? _ WX!!j±j?/ [ _° /'_? K'_±JjW '_W±~?=h

4'j K_ ~ ± X— j/j ± %±~%j±/Xj= ?jjWjW /~ ~%/X—X\j /'j ±j=~^/X~? ~ ! _ K_ ~±X— j/j± _±j WX!E

!j±j?/ TX? !_K/* /'j° _±j K~—%j/j° ~%%~=X/j' !~± jjK/±~?= _ ? W K'_±JjW '_W ±~ ? = Dp7h

B~± /'X= ±j_=~? * /'j j jK/±~— _J?j/XK _?W '_W±~?XK =jK/X~?= _ ±j ^=^_° >^X/ [X/' WX!E

!j±j?/ K~— %~=X/X~?= h v! /'j K~—%~=X/X~? ~! /'j j jK /±~— _J?j /XK =jK/X~? X= K'~=j? !~±

~%/X— _ j jK /±~— _J?j /XK j?j±J° ±j=~^/X~?* /'j? =X?Kj /'j =XJ?_= !±~— /' j jjK/±~E

— _J?j/XK =jK /X~? _±j ^=jW X? K~—>X?_/X~? [X/' /'~=j !±~— /' j '_W±~?XK =jK/X~? /~

—j_=^±j /' j j?j±J° ~! _ K'_±JjW '_W±~?* /'j j?j±J° ±j=~ ^ /X~? !~± K'_±JjW '_W±~?=

=^!!j±= TK'_±JjW '_W±~?= [~^W >j —j_=^±jW > j / /j ± [X/' _ K_ ~ ± X— j /j ± [X/' FFO jjK/±~E

—_J?j/XK =jK / X~? X? !±~?/ ~! X/'h 4'^=* ~?JX/^WX?_ =jJ — j ? /_ / X~ ? _~[= !~± j]Kjj?/

j?j±J° ±j=~ ^ /X~? !~± ~?j /°%j ~! %_±/XKj >^/ ±_ /' j ± %~~± j?j±J° ±j=~^/X~? !~± /'j

~ /'j± /°%j ~ ! %_±/XKj h

)~?JX/^W X?_ =jJ— j?/_/X~? _=~ _~[= !~± %_±/XKj XWj?/X! XK_ /X~? h ZX?Kj jjK/±~?=

T_?W <=' Wj%~= X/ —~=/ ~! /'jX± j?j±J° X? /'j j jK /±~— _J?j/XK =jK/X~? * ['j±j_= K'_±JjW

'_W±~?= W j % ~ = X / j?j±J° X? >~/' =jK/X~?=* jjK/±~?= T_?W = =' K_? >j W X=K±X— X?_/jW !±~—

K'_±JjW ' _ W ±~ ? = >° K^ / / X? J ~? /'j ±_/X~ ~! =XJ?_ X? /'j '_W ±~ ? XK =jK/X~? [X/' /'j

=XJ?_ X? /'j j jK /±~— _J?j/XK =jK/X~?h

6 'Xj ~?J X/^W X?_ =jJ— j?/_/X~? _~[= %_±/XKj XWj?/X! XK_ /X~? _?W /'j ~ % / X— X\_ E

/X~? ~! ±j=~ ^ /X~? !~± ~?j /°%j ~! %_±/XKj* X/ X? /±~W^Kj= =XJ?X!XK_?/ K~— %XK_/X~?= X?

/'j K_ X> ±_ /X~? ~ ! /'j K_~±X—j/j±h 4'j=j K~—%XK_/X~?= _±j W X=K^==jW X? g ' _ % /j ± ch

ab


electrons and photons are absorbed in a relatively small amount of material (see

Section -l . .5.1). the electromagnetic section is placed in front of (as seen by particles

emerging from the interaction point) the hadronic section. The hadronic section

combined with the electromagnetic section measures the energy of charged hadrons

which require more material to deposit their energy.

Electrons and photons depo-;it their energy in a different way than charged hadrons.

The calorimeter propPrties needed to optimize the resolution of a calorimeter are dif

ferent (in fact. they are completely opposite) for electrons and charged hadrons [7].

For this reason. the electromagnetic and hadronic sections an.• usually built with dif

ferent compositions. If the composition of the electromagnetic section is chosen for

optimal elf'ctromagnetir: energy resolution. then since the signals from tht> electro

magnetic section are used in combination with those from t lH· hadrunic section to

measure the erwrgy of a charged hadron. the energy resolution for charged hadrons

suffers ( charged hadrons would bl' measured bPCter with a calorimetl'f with no elt>ctru

magnetic section in front of it). Thus. longitudinal segmentation allows for excellent

energy resolution for one type of particle but rather poor energy resolution for the

other type of particll'.

Longitudinal segmentation also allows for particle identification. Since electrons

(and -~s) clPposit most of their energy in the> fllectromagnetic section. whereas charged

hadrons deposit energy in both sections, electrons (and ~rs) can be discriminated from

charged hadrons by cutting on the ratio of signal in the hadronic section with the

signal in the electromagnetic section.

\\'hile longitudinal segmentation allows particle identifiecition and the optimiza

tion of resolution for one type of particle, it introduces significant complications in

the calibration of the calorimeter. These complications are discussed in Chapter -5.

29

1Ce 5>ky■]^¥c~*k■py Sk¥' ’,^Wk]’

6 'j? _ ? jjK/±~? X? /j ±_K /= [X/' — _ / /j ± * X/ ~=j= j?j±J° ;X_ X~? X\_ /X~? ~± y±j—=E

= /±_' ^?J ±_W X_ /X~? h L ' ~ /~ ? = X?/j±_K/ ; X_ /' j %'~/~jjK/±XK j!!jK/h g ~ — % /~ ? =K_ //j±E

X?J ~± %_ X± % ±~W^K/X~? h x ? jjK/±~? T~± %'~/~?' /' _ / ' X/= _ >~K9 ~! — _/ /j ± [X/'

j?~^J' j?j±J° Tlmss - j1' [X = /_ ± / _ %±~Kj== 9?~[? _= _ K_=K_Wj ~± ='~[j±h v/

^=^_° ^=j= =~_% _?W =' _ — % ~ ~ _?W =~— j/X— j= X9j= /~ /_9j _ > _ /' X? = /j_Wmh v?

/'X= %±~Kj==* /'j jjK/±~? ±_WX_/j= y ±j— ==/±_' ^?J %'~/~?=h 4'~=j %'~ /~?= X? /^±?

X?/j±_K/ ;X_ ~?j ~! /'jX± X? /j±_K /X~? %±~Kj==j= T%'~/~jjK/±XK j!!jK/h g ~ — % /~ ? =K_//j±E

X?J ~± %_X± % ±~W^K/X~? 'h L '~ /~?= [X/' j?~^J' j?j±J° TcEms -j1' [X %±~W^Kj _?

j?j±Jj/XK j jK /±~? E%~=X/±~? %_X±h 4'j ±j=^ / X?J jjK/±~? _?W %~= X/±~? K_? _=~ j—X/

y ±j— ==/±_' ^?J %'~/~?= ['XK' [X/' j?~^J' j?j±J° K_? K ±j_ /j ~ /'j± j jK/±~?E%~=X/±~?

%_X±= _?W =~ ~?h 4'^=* /' j ?^— >j± ~! %_ ±/ XK j= X? /j ±_K /X?J X?=XWj /' j — _/j±X_ _= _

!^?K/X~? ~! W j % /' X?K±j_=j=h x/ =~—j %~ X? / TK_jW /'j ='~[j± — _] X— ^— ' X?=XWj /'j

—_/j±X_* j jK /±~?= % ±~W^KjW >° /'j ='~[j± %±~Kj== ?~ ~?Jj± '_;j j?~^J' j?j±J° /~

j— X/ y ±j— ==/±_' ^?J ±_W X_ /X~ ? * _?W /'j° = X— %° Wj%~=X/ /'j X± j?j±J° X? /'j —_/j±X_

>° X~?X\X?J X/h x/ ~[j± j?j±JXj=* %'~/~?= /~ ~ [X X? /j ±_K / ;X_ g ~ — % /~ ? =K_//j±X?J

~± /'j %'~ /~jjK/± XK j!!jK/* /'^= ?~/ — ^ /X% ° X?J /'j ?^— >j± ~! ='~[j± %_±/XKj= X?/j±E

_K/X?Jh v? /' X= [_°h >j°~?W /'j ='~[j± — _] X— ^— * /'j ?^— >j± ~! %_±/ XK j= WjK±j_=j=h

v/ ='~^W >j ?~/jW / ' _ / _ ~! /'j 9 X?j/XK j?j±J° ~! /'j X?K~— X?J jjK/±~? T~±

%'~/~?' X= j;j?/^_° W j%~= X/jW X? /'j — _ /j ± X_ X? /'j !~±— ~! X~?X\_/X~? K'_±Jj ['XK'

K_? >j — j_=^ ±jW ~± >° j]K X/ X?J _/~— = ~ ± —~jK^j= ['XK' ^%~? ±j /^ ±? X? J /~ /'j

J±~^?W = /_ /j j— X/ XJ'/ / ' _ / K_? >j — j_=^±jW h

4'X= ~!/j? %±~;j= WX!!XK^/ /~ —j_=^±jh

ns


-1.5 Electromagnetic (em) shmvers

\\"hen an electron interacts with matter. it loses energy via ionization or Brems

strahlung radiation. Photons interact via the photoelectric effect. Compton scatter

ing or pair production. ..\n electron ( or photon) that hits a block of matter with

enough energy (>100 .\[e\") will start a process known as a cascade or shower. It

usually uses soap and shampoo and sometimes likes to take a bath instead t. In

this process. the eienron radiates Bremsstrahlung photons. Those photons in turn

int1~ract via one of their interaction processes (photoelectric effect. Compton scatter

ing or pair production). Photons with enough energy (-5-10 .\[e\") will produce an

enPrgetic elPctron-positron pair. The resulting electron and positron can also emit

Bremsstrahlung photons which with enough energy can create otlwr electron-positron

pairs and so on. Thus. the number of particles interacting inside the material ;~ a

function of depth increases. At some point ( called the shmvPr maximum) insidP tlw

material. electrons produced by the shower process no longt>r have enough energy to

emit Bremsstrahlung radiation. and they simply deposit their energy in the material

by ionizing it. . .\t lower energies. photons too will interact \·ia Compton scattering

or the photoelectric effect, thus not multiplying the number of shower particles inter

acting. In this way, beyond the shower maximum. the number of particles decrl:',t.Ses.

It should be noted that all of the kinetic energy of the incoming electron ( or

photon) is eventually deposited in the material in the form of ionization charge which

can be mea:mred or by exciting atoms or molecules which upon returning to the

ground state emit light that can be measured.

1 This often proves difficult to measure.

30

uhchm L'°=XK_ =X\j ~! j— ='~[j±=

4 ' j 0q%<qN<£* ]—*4N>B T M. X= Wj!X?jW _= /' j W X=/_?Kj ~;j± ['XK' _ 'XJ'Ej?j±J° TYl F

kj1' jjK/±~? ~± %~=X/±~? ~=j=* ~? _;j±_Jjh m # — H ] ~! X/= j?j ±J° /~ y±j— ==/±_' ^?J

±_W X_ /X~? h 4'X= ;_±X_>j X= ^=jW /~ Wj=K±X>j /' j ~?JX/^WX?_ W X— j?=X~? ~! _? jjK/±~E

— _J?j/XK ='~[j± X? _ — _/j±X_ X?Wj%j?Wj?/ [_°h 4'j ±_ W X_ / X~ ? j?J/'= ~! L> _?W

Bj _±j shcr K— _ ? W mhpr K—h ±j=%jK/X;j°h 4 ' j ±_WX_/X~? j? J /' ~ ! [_/j± X= nrhm K—h

4'^=* _? jjK/±~? ~=j= /'j =_— j !±_K/X~? ~! X/= j?j±J° X? shcr K— ~! L>h mhpr K— ~!

Bjh ~± nrhm K— ~! [_/j±h

4 'j Wj% /' TX? ^?X/= ~! xA~' ~ ! /'j ='~[j± — _]X— ^— W j % j ? W = ~J_±X/'—XK_° ~?

/'j j?j±J° ~! /'j X?K~—X?J jjK/±~?h 4'j _ /j ±_ Wj;j~%— j?/ ~! _? jjK/±~—_J?j/XK

='~[j± X= X?Wj%j?Wj?/ ~! /'j j?j±J° ~! /'j X?K~— X?J %_±/XKjh

uhcha 0j=~^/X~? ~ ! j— ='~[j±=

w?j±J° ['XK' X= Wj%~=X/jW X? /' j _K/X;j % ~ ± /X~ ? ~! /'j K _ ~ ± X— j /j ± X= /^ ±?jW X?/~ _

=XJ?_* >^ / j?j±J° ['XK' X= Wj%~=X/jW X? /'j %_==X;j _°j±= TX? =_— %X?J K_~±X—j/j±='

W~j= ?~/ ±j=^/ X? _ =XJ?_h 4'j !^K/^_/X~?= X? /' j _— ~^?/ ~ ! j?j±J° ['XK' X= Wj%~=X/jW

X? /'j _K/X;j — _/j ±X_ ~! /'j K_ ~ ±X— j/j± T_?W /'^= ! ^K /^_/X~?= X? /'j =XJ?_' _±j

K_jW 1qS•]<*4 :]R5 NRqN<£*1 v? =_— %X?J K_~±X— j/j±=* = _ — % X? J !^K/^_/X~?= ^=^_°

W ~ — X? _ /j /'j j?j±J° ±j=~^/X~? !~± j— ='~[j±=h Z_— %X?J ! ^K /^_ / X~?= !~~[ L~X==~?

=/_ /X= /XK= h 4'^=* X! _ %_±/XKj ~! j?j±J° D % ±~W^Kj= * %'~ /~jjK /±~?= ~? _;j±_Jj* /'j

j;j?/E/~Ej;j?/ !^K/^_/X~?= ~? /' _ / ?^— >j± _±j 1\0^/X~?'

X= /'j? =E — \ D f 1 \ * \ * f F : 1 \ * B v ! _ K_~±X— j/j± X= X?j_±* /' j? _ %_±/XKj [X/' j?j±J°

€ D [X %±~W^Kj € * %'~/~jjK/±~?= ['j? _>=~ ±>jW >° /'j K_ ~ ± X— j/j± h 4 'j ±j_/X;j

%±jKX=X~? ~! /'j j?j±J° — j_=^±j— j?/ X= /'j? 6 : € * \ € * f 1 : € \ € » F \ Q : * B _ !_K/~± 6 \ € \ €

> j / /j ± /' _? !~± _ %_±/XK j ~! j?j±J° D B B~± X?j_ ± K_~±X— j/j±= /' X= j_W= /~ /'j !~±—

nm


-l.5.1 Physical size of em showers

The radiation length. X0 • is defined as the distance over which a high-energy (>> 1

Ge\·) electron or positron loses. on average. 1 - e- 1 of its energy to Bremsstrahlung

radiation. This variable is used to describe the longitudinal dimension of an electro

magnetic shower in a material independent way. The radiation lengths of Pb and

Fe are 0.56 cm and 1. 76 cm. respectively. The radiation length of water is 36.1 cm.

Thus. an electron loses the samP fraction of its energy in 0.56 cm of Pb. 1. 76 cm of

Fe. or 36. l cm of water.

The depth (in units of X0 ) of the shower maximum depends logarithmically on

the energy of the incoming electron. The lateral development of an electromagnetic

showPr is independent of thP enNgy of tht> incoming partidP.

-t.3.2 Rt1sol11tion of em showi-•rs

Energy which is deposited in the active portion of the calorimeter is turned into a

signal. but energy which is deposited in the passive layers ( in sampling calorimeters)

• does not result in a signal. The fluctuations in the amount of energy which is deposited

in the active material of the calorimeter (and thus fluctuations in the signal) are

callerl sampling fiu.ctu.ations In sampling cal,)rimeters, sampling fluctuations usually

dominate the energy resolution for em showers. Sampling fluctuations follow Poisson

statistics. Thus. if a particle of energy £ produces n photoelectrons on average, the

event-to-event fluctuations on that number a.re fa. The relative precision with which

the calorimeter can measure energy (i.e., the relative width of the signal distribution)

is then a£/ E = .,/n/ n = 1/ y'n. If a calorimeter is linear, then a particle with energy

xE will produce In photoelectrons ,vhen absorbed by the calorimeter. The relative

precision of the energy measurement is then /xii./ In = fi/x · 1/ fa. a factor -Ji/ x

better than fur a particle of energy £. For linear calorimeters this leads to the form

31

~!/j? *^~/jW _= /'j j?j±J° ±j=~^/X~? ~! _ K_ ~±X— j/j±

!PUX U m q\QEHD Tuhm'

['j±j _ X= _ % _ ±_ — j /j ± K'_±_K/j±X\ X?J /'j K_ ~ ±X— j/j± *^_X/° _? W D X= JX;j? X? kj1h

4 ' j _±Jj± /'j 1qS •]<*4 :0q5N<£*■ ['XK' X= Wj!X?jW _= /'j j?j±J° Wj%~=X/jW >° _ — X?XE

— ^ — X~?X\X?J %_±/ XK j T—X%' X? /'j _K/X;j K_ ~ ±X— j/j± _°j±=* — j_=^±jW ±j_/X;j /~ /'j

/~ /_ j?j±J° Wj%~=X/jW >° =^K' %_±/XK j= X? /'j K_~±X— j/j±* /' j > j / /j ± /'j j?j±J° ±j=E

~ ^ /X~? !^± j±_ ='~[j± Wj/jK/X~?U♦h v? '~— ~Jj?j~^= K_~±X— j/j±=* /'j =_— %X?J !±_K/X~?

X= mss&4 h =~ /'j±j _±j ?~ =_—%X?J !^K/^_/X~?=h B~± /'X= ±j_=~?* '~—~Jj?~^= K_ ~±X— jE

/j±= '_;j /'j >j=/ ±j=~^/X~? !~± j jK /±~— _J?j/XK ='~[j±=h 4 ' j j?j±J° ±j=~^/X~? ~!

/'j=j K_~±X— j/j±= X= X—X/jW >° !_K/~±= =^K' _= XJ'/ K~jK/X~? j!!XKXj?K°h

uhr q_W±~?XK ='~[j±=

6 'j? _ ' XJ' j?j±J° K'_±JjW ' _ W ±~ ? 'X/= _ >~K9 ~! — _ / /j ± * /'j ='~[j± /' _ / WjE

;j~%= X= —~±j K~— %XK_ /jW /'_? /'j j jK /±~— _J?j/XK ='~[j± Wj=K±X>jW X? ZjK/X~? uhch

1C 'Xj /'j >_=XK XWj_ X= /'j =_—j* /'j ?^— >j± ~! %_±/XKj= X? /j ±_K / X?J X? /'j — _/j±X_

X?K±j_=j= ^% /~ _ Kj±/_ X? Wj%/' X? /'j K_ ~±X— j/j± _ ? W /'j? WjK±j_=j= _!/j± /' _ / %~ X? /*

/'j ?^— >j± ~! WX!!j±j?/ %±~Kj==j= / ' _ / — _° K~? /± X>^ /j /~ /' X= %'j?~—j?~? X= —^K'

_±Jj±h 4'j X?K~— X?J '_W±~? K_? X? /j ±_K / = /±~?J ° [X/' /'j ?^KjX ~! /'j _>=~ ±>j±

— _ /j ± X_ _?W % ±~ /~?= _?W ?j^/±~?= K_? >j ±jj_=jW !±~— /'j ?^KjXh x=~ ['j? /'j

X?K~— X?J %_±/XKj X? /j±_K /= [X/' _ ?^Kj^=* /'j %_±/XKj K_? K'_?Jj X/= XWj?/X/° _?W

% ±~W^Kj _WWX/ X~?_ —j=~?= ~± >_±°~?=h Z~—j ~! /'j=j '_W±~?= _±j ?j^/±_ _?W WjK_°

j jK /±~— _J?j/XK_ ; _= X= WX=K^==jW X? ZjK/X~? uhrhnh

j WqS•]<*4 :0—+R—*56 _=~ %_°= _ ±~j X? /'j j?j±J° ±j=~^/X~? ~! _ K_~±X—j/j± !~± j— ='~[j±

Wj/jK/X~? DrVh

na


often quoted as the energy resolution of a calorimeter

(-1. 1)

where a is a parameter characterizing the calorimeter quality and £ is given in Ge\·.

The larger the sampling fraction. which is defined as tlw energy deposited by a mini

mum ionizing particle (mip) in the active calorimeter layers. measured relati,·e to the

total energy deposited by such particles in the calorimNer. the better the energy res

olution fur em shower detection:!. In homogPneous calorinwters. the sampling fraction

is 1007t.. so there are no sampling fluctuations. For this reason. homogenous calorime

ters have tlw lwst resolution for electromagm1 tic showns. Tlw ent'rgy resolution of

these calorimetPrs is limited by factors such as light collection Pffinency.

-l.6 Hadronic showers

\rl11~n a high energy charged hadron hits a. block of matter. the shmwr that de

velops is more complicated than the electromagnetic shower described iu Section -!.5.

\\"hili> tlu• basic idea is the same. the number of particles interacting in the material

im:re,L.,es up to a certain depth in the calorimeter and then decreases after that point.

the number of different processes that may contribute to this phenomenon is much

larger. The incoming hadron can interact strongly with the nuclei of the absorber

material and protons and neutrons can be released from the nuclei. ...\lso when the

incoming particle interacts with a nucleus, the particle can change its identity and

produce additional mesons or baryons. Some of these hadrons are neutral and decay

electromagnetically as is discussed in Section -!.6.3.

i Sampling frequency also plays a role in the ener6'Y resolution of a calorimeter for em shower

detection (6j.

32

uhrhm L'°=XK_ =X\j ~! ' _ W ±~ ? ='~[j±=

q_W±~? ='~[j±= _±j = % _ / X_ ° _±Jj± / ' _ ? j jK /±~— _J?j /XK ='~[j±=* > ~ /' ~?JX/Ê

WX?_° _?W _/j±_°h q _ W ±~ ? ='~[j±= _ ±j K'_±_K /j ± X\jW >° /'j ?^Kj_± X? /j±_K /X~?

j?J/'h xO ['XK' X= Wj!X?jW _= /'j _;j±_Jj W X= /_ ? K j _ 'XJ' j?j±J° '_W ±~? — ^=/ /±_;j

X?=XWj _ — _/j±X_ >j!~±j _ ?^K j_± X? /j ±_K / X~ ? ~KK^±=h 4 ' j %±~>_>XX/° _ '_W±~? [X

?~/ ^?Wj±J~ _ ?^Kj_± X? /j ±_K / X~ ? _!/j± / ±_ ; j X? J _ W X= /_?Kj K X?=XWj _ — _/j ±X_ X=

k m Tuha'

8?X9j jjK/±~?=* '_W±~?= K_? % j ? j /±_ /j _ — _/j ±X_ * ^ X /j Wjj%° >j!~±j = /_ ± / X? J _

='~[j±h 4'^=* /'j ! ^K /^_ /X~?= X? /'j ~ ? J X/^ W X? _ j?j±J° Wj%~=X/ %±~!Xj _±j _±Jjh

x= [X/' j jK/±~— _J?j/XK ='~[j±=* /'j _;j ±_Jj ~?JX/^WX?_ Wj;j~%— j?/ ~! _ '_W±~?

='~[j± Wj%j?W= ~J_±X /'— XK_° ~? /'j j ? j ±J ° ~ ! /'j X?K~— X?J %_±/XKjh 8?X9j jjKE

/±~— _J?j/XK ='~[j±=* '~[j;j±* /'j / ±_? =;j±=j WX— j?=X~?= ~! '_W±~? ='~[j±= >jK~—j

1Sq]]—0 [X/' X?K±j_=X?J j?j±J° ~ ! /'j X? K~ — X? J %_±/XKjh 4 ' X= X= W^j /~ /'j X?K±j_=j

X? /'j jjK/±~— _J?j/XK K ~ — % ~ ? j ? / ~! _ ' _ W ±~ ? ='~[j± _= /' j j?j±J° ~! /'j X?K~—X?J

%_±/XKj X?K±j_=j= T=jj ZjK/X~? uhrhn'h

uhrha v?;X=X>j j?j±J°

Q?j ~! /'j >XJJj=/ WX!!j±j?Kj= >j/[jj? j jK /±~— _J?j /XK _ ? W '_W±~?XK ='~[j±= X=

/'j %'j?~— j?~? ~! <*_<1<9]— —*—046■ j?j±J° [ 'XK' X= Wj%~=X/jW X? /'j K_ ~ ± X— j/j ± >^/

['XK' W~j= ?~/ ±j=^/ X? _ — j_=^ ±_> j = XJ?_h Z X?Kj ?^KjX '_;j _±Jj > X?W X?J j?j±JXj=*

X/ /_9j= _ K~?=XWj±_>j _ — ~ ^ ? / ~ ! j?j±J° /~ > ±j _ 9 ^% _ ?^Kj^=h 4'j j?j±J° ^=jW /~ W~

=~ W~j= ?~/ ±j=^/ X? _ — j_ =^ ±_> j =XJ?_h 4 ' j !^K /^_/X~?= X? /'j _— ~^? / ~! X?;X=X>j

j?j±J° !±~— j;j?/ /~ j;j?/ _±j _±Jj* ~? _; j ±_J j usR ~! /'j ?~?Ej— K~— %~?j? /h 4'^=*

/'j >j=/ j?j±J° ±j=~^/X~? /' _ / K_? >j _ / / _ X? j W !~± '_W ±~? XK ='~[j±= X= X?/±X?=XK_°

[~±=j /'_? /' _ / !~± j jK /±~— _J?j /XK ='~[j±=h

nn


-l.6.1 Physical size of hadron showers

Hadron showers are spatially larger than electromagnetic showers. both longitu

dinally and laterally. Hadron showers are characterized by the nuclear interaction

length. ,\0 which is defined as the average distance a high energy hadron must travel

inside a material before a nuclear interaction occurs. The probability a hadron will

not undergo a nuclear interaction after travelling a distance .: inside a material is

p = e-=1-\0. (-L~)

Cnlike electrons, hadrons can penetrate a material quite deeply befon' starting a

showpr. Thus. tht> fluctllations in the longitudinal ent>rgy dq)(Jsit profile an• largP .

. .\s with electromagnetic showers. the an'rage longitudinal <lewlupment of a hadron

shmn'r dt•1wnds logarithmically un the niergy of tlw incoming particle. C nlike elec

tromagnetic showers, however. the transverse dimensions of hadron showers become

smalla with incn•asing energy of the incoming particle. This is due to the increase

in the electromagnetic component of a hadron showPr as the energy of the incoming

particle increase:; (see Section -l.6.3).

-L6.2 Invisible energy

One of the biggest differences between electromagnetic and ha.dronic showers is

the phenomenon of inc-i:,ible energy. energy which is deposited in the calorimeter but

which does not result in a measurable signal. Since nuclei have large binding energies.

it takes a considerable amount of energy to break up a nucleus. The energy used to do

so does not result in a measurable signal. The fluctuations in the amount of invisible

energy from event to event are large, on average 40o/c of the non-em component. Thus,

the best energy resolution that can be attained for hadronic showers is intrinsically

worse than that for electromagnetic showers.

33

uhrhn w jK/±~— _J?j/XK K~— %~?j?/ ~! '_W±~? ='~[j±=

x ?~ /'j ± WX!!j±j?Kj >j/[jj? j jK/±~— _J?j/XK _ ? W '_W±~?XK ='~[j±= / ' _ / [~±=j?=

/'j '_W±~?XK j?j±J° ±j=~^/X~? X? — _?° K_~±X— j/j±= T?~?K~— %j?=_/X?J ~?j=' X= /'j

!_K/ /' _ / /'j±j X= _? j jK/±~— _J?j/XK K~—%~?j?/ ~ ! '_W±~?XK ='~[j±=h 6 'j? _ K'_±JjW

'_W±~? X? /j ±_K /= [X/' _? _>=~±>j± ?^Kj^=* _ ;_±Xj /° ~! %±~Kj==j= K_? /^ ±? /' j X?K~—E

X?J '_W±~? X?/~ _ WX!!j±j?/ '_W±~? * ~± K_? /^ ±? /' j X?K~—X?J '_W±~? X?/~ — _? ° ?j[

'_W±~?=h Z~—j ~! /'j=j '_W±~?= T~? _;j±_Jj m in ~! /'j—' _±% ?j^/±_ T— ~=/° ±±“=

_? W +=' _? W WjK_° j jK/±~— _J?j/XK_° X?/~ %'~/~?=h 4'j=j %'~ /~?= %±~W^Kj jjK/±~E

— _J?j/XK ='~[j±=h 6j [X ±j!j± /~ /'j %~±/X~? ~ ! _ '_W±~? ='~[j± ['XK' j?W= ^% _=

?j^ /±_ —j=~?= _?W /'^= _= jjK/±~— _J?j/XK ='~[j±= X? /'X= [_° _= /'j —]—5N0£Sq4*—N<5

°R0*{ 5£S •£*—*N ~± <3 5£S•£*—*N ~! /'j ='~[j±h 6j [X ±j!j± /~ /'j ~ /'j± %~ ± /X~? ~!

/'j ='~[j± oX= /'j >q%0£*<5 5£S•£*—*N ~± *£**—S 5£S•£*—*N ~ ! /'j '_W±~? ='~[j±h

4 'j !±_K/X~? ~! /'j X?K~—X?J ' _ W ±~ ? ♦= j?j±J° ['XK' j?W= ^% _= /'j j jK /±~— _JE

?j/XK K~— %~?j?/ ;_±Xj= J±j_/° !±~— ~?j j;j?/ /~ /'j ?j]/h x=~* ~? _;j±_Jj* /'j

j jK /±~— _J?j/XK K~— %~?j?/ X?K±j_=j= _= /'j j?j±J° ~! /'j X?K~— X?J '_W±~? X?K±j_=j=h

4 ' j /[~ %~X? /= '_;j X— %~±/_? / K~?=j*^j?Kj= !~± /' j ±j=~^/X~? _? W ±j=%~?=j TWj!X?jW

X? ZjK/X~? uhrhu'h ±j=%jK/X;j° ~! _ K_~±X—j/j±h

uhrhu g ~— %j?=_ / X~? _?W ?~?K~— %j?=_/X~? Tj i' '

v? —~=/ K_~±X— j/j±=* /'j _— ~^? / ~ ! =XJ?_ % ±~W^KjW >° _ cs k j1 K'_±JjW '_W±~?

X= =— _j± /' _ ? /'j _— ~^? / ~! =XJ?_ %±~W^KjW >° _ cs kj1 jjK/±~? ~± %'~ /~? h 4'X=

X= W^j /~ /'j X?;X=X>j j?j±J° %'j?~— j?~? WX=K^==jW X? ZjK/X~? uhrhah v? _ '_W±~?

='~[j±* =~—j j?j±J° !±~— /'j X?K~— X?J '_W±~? X= ^=jW /~ >±j_9 ^% _>=~±>j± ?^KjX

['XK' X? Jj?j±_ W~j= ?~/ %±~W^Kj _ =XJ?_h

4 ' j 0—1•£*1— ~! _ K_~±X— j/j± /~ _ Kj±/_X? /°%j ~ ! %_±/XKj X= Wj!X?jW _= /'j _;j±_Jj

K_ ~ ± X— j/j± =XJ?_ WX;XWjW >° /'j X?K~— X?J j?j±J° ~! /'j %_±/ XK j /'_ / K_^=jW /'j

=XJ?_h 4 'j ±j=%~?=j !~± _ /°%j ~! %_±/XKj * h1 X= Wj?~ /jW = X— %° _= xNh 4'j ±j=%~?=j

nu


-l.6.3 Electromagnetic component of hadron showers

.--\nother difference between electromagnetic and hadronic showers that worsens

the hadronic energy resolution in many calorimeters (noncompensating ones) is the

fact that there is an electromagnetic component of hadronic showers. \\"hen a charged

hadron interacts with an absorber nucleus. a variety of processes can turn the incom

ing hadron into a different hadron. or can turn the incoming hadron into many new

hadrons. Some of these hadrons ( on awrage 1/:3 of them) arP neutral ( mostly :.0s

and r1s) and decay electromagnetically into photons. These photons produce electro

magnetic showers. \\"e will refer to the portion of a hadron shmver which ends up as

neutral mesons and thus as Plectromagnetic showers in this way as the d1:ctroma9netic

(em) component or :.0 component of tlH' showPr. \\"e will rdf'r tu the other portion of

the shower as the hwironic component or nor1-rm component of thP hadron showPr.

Tlw fraction of the in<'oming hadron ·s energy which ends up as the 11 lectromag

netic component \·aries greatly from one event to the next. .--\lso. on ,n-erage. the

electromagnetic component increases as the energy of the incoming hadron increases.

The two points have important consequences for the resolution and response (defined

, in Section -l.6.-!). respectively of a calorimeter.

-!.6.-1 Compensation and noncompf'nsation (e/h)

In most calorimeters, the amount of signal produced by a 50 Ge\· charged hadron

is smaller than the amount of signal produced by a 50 Ge\" electron or photon. This

is due to the invisible energy phenomenon discussed in Section --l.6.2. In a hadron

shower, some energy from the incoming hadron is used to break up absorber nuclei

which in general does not produce a signal.

The re .. ;pon.se of a calorimeter to a certain type of particle is defined as the average

calorimeter signal divided by the incoming energy of the particle that caused the

signal. The response for a type of particle, X is denoted :;imply as X. The response

3--l

~! _ K_ ~ ± X— j/j± /~ jjK/±~?= _?W %X~?=h !~± X?=/_?Kj* X= j _?W

4 'j j ] /j? / /~ ['XK' /' j K_~±X— j/j± =XJ?_= !±~— jjK/±~?= _?W K'_±JjW '_W±~?= ~!

/'j =_— j j?j±J° WX!!j± X? _ K_~±X— j/j± X= JX;j? >° _ * ^ _ ? / X /° 9?~[? _= /'j — \> ;_^j*

/'j ±j=%~?=j ~! /'j K_ ~ ±X— j/j± /~ j jK /±~?= WX;XWjW >° /'j ±j=%~?=j ~! /'j K_~±X— j/j±

/~ /'j '_W±~? XK K~— %~?j?/ ~! '_W±~? ='~[j±=* >B 4 'j * ^_? /X /° > X= JX;j? >°

> m i±j/ ■ 0—] uE : • » • E!E i $ ■ * E! i —; ■ <*_ Tuhn'

['j±j i ±jh : • B i $ h i X?; X= /' j !±_K/X~? ~ ! ?~?Ej— ='~[j± j?j±J° K_±±XjW >° ±j_/X;X=/XK

K'_±JjW %X~?=h =%__/X~? %±~/~?=* j;_%~±_ /X~? ?j^/±~?=* _?W X?;X=X>j j?j±J° T^=jW

/~ ±jj_=j % ±~ /~?= _?W ?j^ /±~?= !±~— _>=~ ±>j ± ?^KjX'* _ ? W 0—]B •B * _? W <*_ _±j /'j

K_ ~±X— j/j± A= ±j=%~?=j= /~ ±j_/X;X=/XK K'_±JjW %X~?=h =%__ /X~? %±~ /~?=* j;_%~±_/X~?

?j^/±~?=* _? W X?;X=X>j j?j±J°* ±j=%jK/X;j°h 4'j * ^ _? /X /° <*_ X=h >° Wj!X?X/X~?* \j±~h

v? 0<£*5£0*•—*1qN<*4 5q]£0<S—N—0B'■ — \ > =f mh v? — ~=/ K_~±X—j/j±=* /'j ±j=%~?=j

~! /'j K_ ~ ±X— j/j± /~ j jK/±~— _J?j/XK j?j±J° Wj%~=X/X~? X= _±Jj± /' _? /'j ±j=%~?=j

/~ '_W±~?XK j?j±J° Wj%~=X/X~? * — \> l m h v? =~—j K_~±X— j/j±=* /'j =XJ?_ ±j=^/X?J

!±~— _? j jK/±~? _?W K'_±JjW '_W±~? ~ ! /'j =_—j j?j±J° X= ~? _;j±_Jj /'j =_—jh

* Xhjhh — \> E Fh 4'j=j K_~±X— j/j±= _±j ±j!j±±jW /~ _= 5£S•—*1qN<*4 5q]£0<S—N—01B v?

/'j=j K_~±X— j/j±=* j X/'j± /'j =XJ?_ % ±~W^KjW >° /'j j jK /±~— _J?j/XK K~— %~?j?/ ~!

'_W±~? ='~[j±= X= =^%%±j==jW /~ =~—j j] /j? / ~± /'j =XJ?_ %±~W^KjW >° /'j '_W±~?XK

K~— %~?j?/ ~! '_W±~? ='~[j±= X= j?'_?KjW /~ =~—j j] /j? / =~ /'_/ /'j ±j=%~?=j ~! /'j

K_ ~±X— j/j± /~ >~ /' /°%j= ~ ! j?j±J° Wj%~=X/ X= j*^_X\jWh

uhrhc g~?=j*^j?Kj= ~! ?~?K~— %j?=_ /X~?

4'j !^K /^_/X~?= !±~— j;j?/ /~ j;j?/ X? /'j j jK/±~— _J?j/XK K~— %~?j?/ ~! '_W±~?

='~[j±= _±j _±Jj _?W ?~/ ~ ! _ k_^==X_? ?_ /^ ±j h v! /'j K_ ~±X— j/j± ±j=%~?=j /~ /'j=j

/[~ /°%j= ~! j?j±J° Wj%~=X/ _±j WX!!j±j?/ T_= X? ?~?K~— %j?=_/X?J K_~±X— j/j±='* /'j?

/'j=j ! ^K /^_/X~?= ^=^_° W~— X?_ /j /'j j?j±J° ±j=~^/X~?h v? K~— %j?=_/X?J K_~±X—jE

nc


of a calorimeter to electrons and pious. for instance. is e and ii.

The extent to which the calorimeter signals from electrons and charged hadrons of

the same energy differ in a calorimeter is given by a quantity known as thee/ h value.

the response of the calorimeter to electrons divided by the response of the calorimeter

to the hadronic component of hadron showers. h. The quantity h is given by

h =fret· rel+ /p · P + fn ·Tl+ finv · ini- (-1.:3)

where !rel· /p- fn- fin\· is the fraction of non-em shower energy carried by relativistic

chargPd pious. spallation protons. evaporation neutrons. and invisible energy ( used

to release protons and neutrons from absorber nuclei). and rel. p. Tl and ini· are thP

calorimPter·s r<'sponscs to n·lativistic charw~d pion:;. spallation protons. evaporation

neutrons. and invisiblt• enPrgy. rPspectivdy. Tht> quantity iru: is. by definition. zPro.

In rwncompnisatiny calori.rneta.-;. e / h i= 1. In most caloriml•tt•rs. tht• n•spons,,

of thP calorinwtPr to f'!ectrumagnetic energy dt·position is larger than the response

to hadronic energy deposition. e/ h > 1. In some calorimeters. the signal resulting

from an elPctron and charged hadron of the same energy is on average the same.

, i.e .. c/h = 1. These calorimeters are rderred to as compni.rnting calorimetas. In

these calorimeters, either the signal produced by the electromagnetic component of

hadron showrrs !~ '.;uppressed to some extent or the signal produced by the h:1.dronic

component of hadron showers is enhanced to some extent so that the response of the

calorimeter to both types of energy deposit is equalized.

-l.6 . .5 Consequences of noncompensation

The fluctuations from event to event in the electromagnetic component of hadron

shmvers are large and not of a Gaussian nature. If the calorimeter response to these

two types of energy deposit are different (as in noncompensating calorimeters), then

these fluctuation::; usually dominate the energy resolution. In compensating calorirne-

:35

/j±= h /'j ±j=%~?=j /~ /'j /[~ /°%j= ~! %_±/XKj= X= /'j =_—jh 4'j?* /' j ! ^K/^_/X~?= X?

/' j j jK/±~— _J?j/XK K~— %~?j?/ ~! '_W±~? ='~[j±= W~ ?~/ _!!jK/ /'j j?j±J° ±j=~^/X~?h

qj?Kj* /'j K_~±X— j/j±= [X/' /'j >j=/ '_W±~? XK j?j±J° ±j=~^/X~? _ ±j K~— %j?=_/X?J

~?j=h

ZX?Kj /'j j jK/±~— _J?j/XK K~— %~?j?/ ~! '_W ±~? XK ='~[j±= X?K±j_=j= ~? _;j±_Jj

[ X/' /'j j?j±J° ~! /'j X?K~—X?J K'_±JjW '_W ±~? * /'j ±j=%~?=j ~! _ ?~?K~— %j?=_ /X?J

K_ ~ ± X— j/j ± X?K±j_=j= _= _ !^?K/X~? ~! j?j±J°h 4'^=* X! /'j ±j=%~?=j X? _ ?~?K~— E

% j?=_ / X?J K_~±X— j/j± /~ _ cs k j1 K'_±JjW %X~? X= cs %'~/~jjK/±~?= %j± k j C h /'j

±j=%~?=j /~ _ mss k j1 K'_±JjW %X~? [X ?~/ >j cs %'~/~jjK/±~?= %j± k j C h >^/ ±_ /' j ±

=~— j/' X?J X9j ps %'~/~jjK/±~?= %j± kj1h v? K~— %j?=_/X?J K_~±X— j/j±=* '~[j;j±*

/' j _;j±_Jj X?K±j_=j X? /'j j jK/±~— _J?j/XK K~— %~?j? / ~! '_W±~? ='~[j±= '_= ?~ j!E

!jK/ ~? /'j ±j=%~?=j _? W K~— %j?=_/X?J K_ ~ ± X— j/j± '_;j _ X?j_± ±j=%~?=j !~± '_W ±~?

='~[j± Wj/jK/X~?h

uhp 0 _W X_ /X~? , _— _Jj v==^j=

uhphm 0_WX_/X~? W_— _Jj =/^WXj= !~± /'j g-Z ;j±° !~±[_±W K_~±X— j/j±

x/ /'j !^/^±j )_±Jj q_W±~? g~XWj± T)q g '* _? ^?%±jKjWj?/jW ^—X?~=X/° _?W

Kj? /j ± ~! —_== j?j±J° [X T'~%j!^°' >j ±j_K'jWh 4'X= K~XWj± [X =_— % ±~ /~?=

[ X/' %±~ /~?= _/ 6\1 < mu 4j1 _?W _? X? /jJ ±_ /jW ^— X?~=X/° ~! < msss !> *F ~;j± FO

°j_±= h ,j/jK/~±= _ / /' X= K~XWj± [X '_;j /~ [ X /' = /_ ? W j?~±—~^= _ — ~ ^ ? /= ~! ±_WX_/X~?h

v? /' j !~±[_±W ±jJX~? °+ l n' j=%jKX_°* /'j W~=j WjX;j±jW /~ /'j Wj/jK/~±= [X >j

j] /±j— j ° _±Jjh < m Ems -k° X? ms °j_±= ~! ±^ ? ? X? J CBe

v / X= X—%j±_/X;j* /'j?* /' _ / /'j Wj/jK /~ ±= >^ X/ _ / /'X= K~XWj± _±j j]/±j— j° ±_W X_ E

/ X~? '_±W h 4'j g-Z j]%j±X— j?/ Tg ~— %_K / - ^~? Z~j?~XW' '_= K'~=j? _ ;j±° !~±[_±W

K_ ~ ± X— j /j ± K~—%~=jW ~! *^_±/\ !X>j±= X/= /'j _K /X;j — _/j±X_ h qj±j [j =^— — _±X\j /'j

GF 3]cD 9 F ) »~«F 9 FOO ]cJ 9 VCE1 *FOFE nks »~®F

nr


ters. the response to the two types of particles is the same. Then. the fluctuations in

the electromagnetic component of hadron showers do not affect the energy resolution.

Hence. the calorimeters with the best hadronic energy resolution are compensating

ones.

Since the electromagnetic component of hadronic showers increases on m·erage

with the energy of the incoming charged hadron. the response of a noncompensating

calorimeter increa:;es as a function of energy. Thus. if the response in a noncom

pensating calorimeter to a 50 Ge\· charged pion is 50 photoelectrons per Ge\·, the

response to a LOO Ge\· charged pion will not be -50 photoelectrons !>f'r Ge\·. bm rather

something like 70 photoelectrons per Ge\·. ln compensating ca.lorinwters. howewr.

the an~ragc incrt'ase in the clectromagnPCic cumporwnt of hadron showers has no ('f

fpct on the response and cump;,nsating calorimeter ha.v1-1 a linear n•sp1mse for hadron

shmwr detection.

--Li Radiation Damage Issues

-Li. l Radiation damagP studies for the C).[S very forward calorimeter

At the future Luge Hadron Collider (LHC). an unprece<lPnted luminosity and

center of mass energy will (hopefully) be reached. This collider \Vilt slam protons

with protons at Js "" 1--l TeV and an integrated luminosity of,...., 1000 tb- 1 over 10

years. Detectors at this collider will have to withstand enormous amounts of radiation.

In the forward region (TJ > 3) especially, the dose delivered to the detectors will be

extremely large."' 1-10 MGy in 10 years of running.a

It is imperative, then. that the detectors built at this collider are extremely radia

tion hard. The C:\IS experiment (Compact ),[uon Solenoid) has chosen a n~ry forward

calorimeter composed of quartz fibers as the active material. Here we summarize the

3 1 Gray= 1 .J kg- 1 = 100 rad= 6.2-t ·101:! McV kg- 1

;35

±j=^ /= ~ ! _ WjWXK_ /jW = /^ W ° ~! /'j j!!jK/= ~! ±_W X_ /X~? W_— _Jj ~? K_~±X— j/j± %j ±!~ ±E

— _? K j X? ['XK' _ % ±~ /~ /° % j ~! /'j ;j±° !~±[_±W K_ ~ ±X— j/j± [_= X ± ±_W X_ /jW T_/ g w 0 5 '

[ X/' /' j /°%j= ~! %_±/ XK j= ±j=%~?=X>j !~± —~=/ ~ ! /'j ±_W X_ /X~? W~=j= _/ /'j )q gh

, j/_ X= ~! /'X= = /^W° * ['XK' [j±j %^> X='jW X? D0 V K_? >j !~^?W X? x%%j?WX] xh

4 ' j Wj /jK /~ ± ^=jW X? /'X= = /^W° K~?=X=/jW ~! /' X? Tshrs —— W X_— j/j ±' *^_±/\ !X>j±=

j— > j W W j W X? _ K~%%j± — _/± X] h 4'j !X>j±= [j±j ~ ±Xj? /jW _~?J /' j W X±jK /X~? /±_;jjW >°

/'j X?K~— X?J %_±/XKj=h 4 'j ='~[j±X?J %_±/XKj= Jj?j±_ /jW gj±j?9~; XJ'/ X? /'j !X>j±=*

_?W % ' ~ /~ ? = j— X//jW [ X/' X? /'j ?^— j±XK_ _% j ± /^ ±j ~! /'j !X>j±= [j±j K_% /^±jW _ ? W

/ ± _ ? = % ~ ± /j W /' ±~^J' X? /j±?_ ±j!jK/X~? /~ /'j !X>j± j?W=h 4'j±j /'j° [j±j K~?;j±/jW

X?/~ %'~ /~jjK /±~?= X? /'j %'~ /~K_ /'~Wj ~! _ Lh-4h _?W /'j WXJX/X\jW ~^ /%^ / ~ ! /'j

L - 4 = K~— %±X=jW /'j K_~±X— j/j± =XJ?_=h 4'j K_~±X— j/j± [_= nnhpc K— X? W j % /'

Taahr . '' _?W [_= K~— %±X=jW ~! ma /~[j±=h 4'j !X>j±= [j±j ±j_W ~^/ _ / ~±+® j?W _?W

— _Wj ±j!jK/X;j >° _ ^— X?^— Wj%~=X/X~? _/ /'j ~ /' j ± j?Wh - ~±j Wj/_X= _>~^/ /' X=

K_ ~ ± X— j /j ± K_? >j !~^?W X? Db7h

uhpha 0 _W X_ /X~? j]%~=^±j

4 ' j ±_W X_ /X~? j]%j±Xj?KjW >° Wj /jK /~ ±= ~ % j ±_ / X? J _/ n d ’±i’ d c _ / /'j ) q g

K~—j= %±X— _±X° !±~— /'j •• K~X=X~?= _= ~%%~=jW /~ >j_—EJ_= X?/j±_K/X~?=h 4 ' j

—~=/ _ > ^ ? W _ ? / %_±/ XK j= j—j±JX?J !±~— /'j X? /j±_K /X~?= _±j ~[ j?j±J° SF k~1' %X~?=h

? j^ /±_ _ ? W K'_±JjWh 0 _W X_ /X~? W _ — _ J j X? /'j K_ ~±X— j/j± ±j=^/= — ~=/° !±~— /'j

j jK /±~— _J?j/XK ='~[j±= X?W^KjW >° %'~ /~?= TWjK_° %±~W^K/= ~! ?j^ /±_ %X~^='* =X?Kj

%'~ /~?= Wj%~=X/ /'j X± j?j±J° X? _ X— X/jW Wj% /' X? /'j K_~±X— j/j±h 4~ —X—XK9 /' X=

= X /^ _ / X~ ? * /' j % ±~ /~ /° % j K_~±X—j/j± — ~W^ j [_= j]%~=jW /~ _? X?/j?=j >j_— ~! shc

kj1A j jK /±~?=* % ±~W^KjW >° /'j ) X?j_± v? 7jK/~± !~± ) w L T)v)' _ / g w 0 5 h 4'j > j_—

X? /j?=X/° W^ ± X?J /'X= j]%~=^±j [_= /°%KX_ ° _ !j[ /X— j msFF j jK/±~?= %j ± =jK~?Wh 4 ' X=

>j_— [_= =/jj±jW %j ±%j?W XK^ _ ± /~ /'j — X±±~±jW !X>j± =^±!_Kj T=jj B XJ^±j uhm'h Q ;j±

< n W_°= * _ /~ /_ ~ ! mhuc E msFV j jK/±~?= [X/' _? j?j±J° ~! shc kj1A j_K' [j±j =j? /

np


results of a dedicated study of the effects of radiation damage on calorimeter perfor

mam:e in which a prototype of the \·ery forward calorimeter was irradiated ( at CER=")

\Vith the types of particles responsible for most of the radiation doses at the LHC.

Details of this study. which were published in (8] can be found in . ..\ppendix . ..\.

The detector used in this study consisted of thin (0.60 mm diameter) quartz fibers

embedded in a copper matrix. The fibers were oriented along the direction travelled by

the incoming particles. The showering particles generated Cerenko\· light in the fibers.

and photons emitted within the numerical aperture of the fibers wen• captured and

transported through internal reflection to the fiber ends. There they were converted

into photoelectrons in the photocat!10de of a P:\IT. and th<' <ligitiz<'d output of the

P:\[Ts comprised tl1e calorimetPr signals. The calurimf't1~r was 33.75 cm in depth

(22.G .\"0 ) and was comprised of 12 towns. The filwrs WPrt' rPad out at one 1•nd and

made reflective by aluminum deposition at tlw otlu•r ,~nd. :\[on• dPtails about this

calorimeter can be found in [!J].

-!. 7.2 Radiation exposure

The radiation experienced by detectors operating at 3 < I'll < 5 at the LHC

comes primarily from the pp collisions as opposed to beam-gas interactions. The

most abundant particles emerging from the interactions are low energy (1 Ge\·) pions.

neutral an<l charged. Radiation damage in the calorimeter results mostly from the

electromagnetic showers induced by photons (decay products of neutral pions), since

photons deposit their energy in a limited depth in the calorimeter. To mimick this

situation, the prototype calorimeter module was exposed to an intense beam of 0.5

GeV electrons, produced by the Linear Injector for LEP (LIL) at CER:\. The beam

intensity during this exposure was typcially a few time 1011 electrons per second. This

beam was steered perpendicular to the mirrored fiber surface (see Figure -Ll). Over

,.._, :3 days, a total of 1.-!5 · 1016 electrons with an energy of 0.5 GeV each were sent

37

X?/~ _? _±j_ ~! _ !j[ K—ah 4'j K_~±X—j/j± >jK_—j *^X/j ±_WX~_K/X;j X? /'X= %±~Kj==*

±j*^X±X?J < n W_°= /~ K~~ W~[? >j!~±j X/ K~^W >j /±_?=%~±/jW /~ /'j /j=/>j_— _±j_

Tqu >j_—X?j _ / gw0P'h

/~ L-4♦=

\)v) yj_—

Tshc kj1 5 {

qu yj_— Tmcs kj1 jN'

BXJ^±j uhme Q±Xj?/_/X~? ~! /'j *^_±/\ !X>j± K_~±X—j/j± %±~/~/°%j W^±X?J /j=/>j_±? =/^WXj= ~! /'j j!!jK/= ~! ±_WX_/X~? W_—_Jjh 4'j /~[j± ?^—>j±X?J =K'j—j ^=jW !~± /'j=j =/^WXj= X= ='~[?h 4'j WX±jK/X~? ~! /'j >j_— ^=jW /~ X±±_WX_/j /'j —~W^j T)v) yj_—' _?W /'j WX±jK/X~? ~! /'j >j_— ^=jW /~ _==j== /'j j!!jK/= ~! X±±_WX_/X~? ~? /'j K_~±X—j/j±= %j±!~±—_?Kj Tqu yj_—' _±j ='~[?h

uhphn , _ /_ x?_°=X=

4'j j!!jK/= ~! /'j K_~±X— j/j±♦= %j±!~±—_?Kj [j±j —j_=^±jW ^=X?J _ >j_— ~! mcs

kj1 jjK/±~?= _ / /'j g w 0 P qu >j_—X?j =j?/ X?/~ /'j Wj/jK/~± =XWj[_°=* Xhjh* %j±%j?E

WXK^_± /~ /'j !X>j± %_?j T=jj BXJ^±j uhm'h 4'j K_~±X—j/j± ±j=%~?=j [_= —j_=^±jW

_= _ !^?K/X~? ~! C * /'j WX=/_?Kj >j/[jj? /'j X—%_K/ %~X?/ ~! /'j %_±/XKj= _?W /'j

_^—X?X\jW !±~?/ !_Kj ~! /'j Wj/jK/~±h x? j]_—%j ~! /'j ±j=^/= ~! =^K' _ EE=K_? X=

='~[? X? BXJ^±j uha_* ['j±j /'j _;j±_Jj =XJ?_ ±jK~±WjW X? 4~[j± c X= %~//jW _= _

!^?K/X~? ~! CB v? BXJ^±j uha>* /'X= W _ /_ X= WX;XWjW X?/~ j;j?/= X? ['XK' /'j jjK/±~?=

j?/j±jW /'j Wj/jK/~± _ / 6 f s # c —— ~± 6 f as # ac — —h yj!~±j /'j X±±_WX_/X~?*

/'j =XJ?_= ±jK~±WjW X? =K_?= ~! /'X= /°%j [j±j %±_K/XK_° X?Wj%j?Wj?/ ~! CB x!/j± /'j

X±±_WX_/X~?* '~[j;j±* _ Kj_± ±jW^K/X~? X? /'j =XJ?_= [_= ~>=j±;jWh 4'X= X= X?WXK_/jW

nt


into an area of a few cm2 • The calorimeter became quite radioactive in this process,

requiring -3 days to cool down before it could be transported to the testbcam area

(H4 beamline at CER.:'-r).

UL Bt:am (0.5 GcV c·)

to PMT's

!rraJ,aic<l .in:.,

H-4 Beam ( 150 GeV e·)

Figure -1. I: Orientation of the quartz fiber calorimeter prototype during testbearn studies of the effects of radiation damage. The tower numbering scheme m;ed for these studies is shown. The direction of the beam used to irradiate the module (LIL Beam) and the direction of the beam used to a.8SCSS the effects of irradiation on the calorimeter's performance (H4 Beam) arc shown.

4. 7.3 Data Analysis

The effects of the calorimeter's performance were measured using a beam of 150

GeV electrons at the CER~ H4 beamline sent into the detector sideways, i.e., perpen

dicular to the fiber plane (see Figure ,LI). The calorimeter response wa.s measured

as a function of z, the distance between the impact point of the particles and the

aluminized front face of the detector. An example of the results of such a z-scan is

shown in Figure 4.2a, where the average signal recorded in Tmver 5 is plotted as a

function of z. In Figure 4.2b, this data is divided into events in which the electron:;

entered the detector at y = 0 - 5 mm or y = 20 - 25 mm. Before the irradiation,

the signals recorded in scans of this type were practically independent of z. After the

irradiation, however, a clear reduction in the signals wa.s observed. This is indicated

38

>° _ K'_?Jj X? /'j ='_%j ~! /'j \E=K_? W_/_* ?_—j° _ 9X?9 _/ _ W j % /' C f mc E a s K—h

4'X= _J±jj= [X/' -~?/j g_±~ =X—^_/X~?= ~! /'j W~=j _>=~±>jW >° /'j K_~±X—j/j±

!±~— /'j )v) >j_— ['XK' ='~[jW /' _ / /'j ±_WX_/X~? j!!jK/= [j±j X—X/jW /~ /'j _±j_

\ d EO K—h

cgQ ntk

nug

K nss nss

ass ars

mss aas

mtsac ns acas

° E as E ac —— =XJ?_ E nsn U m Nc 8

° f s E c —— =XJ?_ E aab ■ a bn <

& x W _ /_ /~ [ j ± c

,j%/' X? K_~±X—j/j±* \ TK—'

BXJ^±j uhae 4'j _;j±_Jj =XJ?_ X? 4~[j± c ±jK~±WjW X? \±E=K_?= [X/' jjK/±~?= j?/j±X?J /'j Wj/jK/~± X? /'j ±jJX~?= 6 f s # c ?^? _?W 6 m as # ac ——* ±j=%jK/X;j°h

uhphu x —~Wj /'_/ ±j%±~W^Kj= W_ /_

6j ^=jW _ -~?/j g_±~ =X—^_/X~? >_=jW ~? _ =X—%j —~Wj X? _? _ //j— %/ /~

±j%±~W^Kj /'j j]%j±X—j?/_ EE=K_?=h v? /'X= —~Wj* /'j ~K_ ~== X? XJ'/ /±_?=—X==X~?

X= %_±_—j/j±X\jW _=

f $ * P qVy C { . * Tuhu'

['j±j ]°C{ X= /'j _ //j?^_/X~? j?J/' _ / _ Wj%/' C X?=XWj /'j K_~±X— j/j± _!/j± /'j

Wj/jK/~± '_= ±jKjX;jW _ ±_WX_/X~? W~=j y °C{ ■ _?W /O ±j%±j=j?/= /'j _//j?^_/X~? j?J/'

X? /'j _>=j?Kj ~! ±_WX_/X~?h 4'j ±_WX_/X~? =j?=X/X;X/° ~! /'j Wj /jK /~ ± X= —j_=^±jW >°

/'j ;_^j ~! /'j %_±_— j/j± _ sh x =—_ ;_^j ~! _~ K~±±j=%~?W= /~ _ =—_ ±_WX_/X~?

=j?=X/X;X/° TXhjh* _ _±Jj ±_WX_/X~? '_±W?j=='h

nb


by a change in the shape of the z-scan data, namely a kink at a depth z = 15 - 20 cm.

This agrees with ~Conte Carlo simulations of the dose absorbed by the calorimeter

from the LIL beam which showed that the radiation effects were limited to the area

z < 20 cm.

sco ..------,..--------, 380 ..-------------,

_ 400

:i

~ JOO C> ·.;

~

~ 200

0 iii (.)

100

a)

• All data lo"' er ;

34C

JOO

260

220

...

b)

. . ..... •·

. . .

I_:_ :,- .= .!O - 25 m.m. s1gr.aJ =- JOJ • 1 ... 5 l I '! = O - 5 mm SJgnal = ::9 .. : 93 L

0 ____________ ___. 180 ----------------0 s 1 c; 1 s za 2s JO JS o 10 t 5 20 25 JO

Depth in calorimeter, z (cm)

Figure -1.2: The average signal in Tower 5 recorded in z-scans with electrons entering the detector in the region::; y = 0 - 5 mm and y = 20 - 25 mm, respectively.

-l. 7-4 ...\ model that reproduces data

\Ve used a ~[onte Carlo simulation based on a simple model m an attempt to

rf'produce the experimental z-scans. In this model, the local loss in light transmission

is parameterized as

1 1 l(z) = lo + aoD(z)l-n (4.4)

where l ( z) is the attenuation length at a depth z inside the calorimeter after the

detector has received a radiation dose D(z), and i0 represents the attenuation length

in the absence of radiation. The radiation sensitivity of the detector is measured by

the value of the parameter a 0• A small value of a 0 corresponds to a small radiation

sensitivity (i.e., a large radiation hardness).

39

6 X/' /' X= —~Wj* = X— ^ _ /j W ±j=%~?=j K^±;j= TjE=K_?=' [j±j ~> /_ X?jW _= !~~[=h

4'j gj±j?9~; XJ'/ % ±~W^KjW _ / _ Kj±/_X? W j % /' C _?W / ±_ % % j W X?=XWj /' j !X>j±= [_=

=%X/ X?/~ /[~ K~— %~?j?/= * [ X/' j*^_ !±_K/X~?= J~X?J /~ /' j ±XJ'/ T S X * = / ±_ XJ ' / /~ /'j

L- 4' _ ? W /~ /'j j!/ T #X * /~ /'j _^—X?X\jW !±~?/ j?W ~ ! /'j !X>j±='h 4 ' j %'~/~?=

X? >~/' K~— %~?j?/= [j±j /±_K9jW X? =/j%= ~! shc K— ~? /' j X± [_° /' ±~ ^ J ' /'j !X>j±h

v? j;j±° = /j% * /'j XJ'/ X? /j?= X/° [_= WX—X?X='jW >° _ !_K /~ ± j ] % D E s hc i i T \ i 'VI [X/' /'j

~K_ _ / /j ? ^ _ / X~ ? j?J/' ] C Z{ _ / Wj%/' CZ j]%±j==jW X? K—h )XJ'/ /±_;jX?J /~ /'j j!/

T #C■ =jj B XJ^±j uhm' [_= _==^— jW /~ ^?Wj±J~ _? X?/j?=X/° ~== ~! asR ^%~ ? ±j!jK/X~?

~!! /'j — X± ±~ ±jW !X>j± j?W h 4 'j ;_^j ~! ]- [_= /_9j? _= as —h y~/' ?^— >j±= [j±j

>_=jW ~? ±j=^ /= ~! — j_=^ ±j— j? /= [X/' _? ^? X±±_W X_ /jW — ~W^j ~! j]_K/° /'j =_—j

K~—%~=X/X~? DbVh v? /'X= [_°* /'j !±_K/X~? ~! /'j gj±j?9~; XJ'/ /±_%%jW X? /'j !X>j±=

/'_ / ±j_K'jW /'j L - 4 [_= K_K^_/jWh y° ±j%j_/X?J /' j Wj=K±X>jW %±~KjW^±j !~±

_ _±Jj ? ^ — > j± ~! %~ X? /= _ / WX!!j±j?/ Wj%/'= TK'* /'j = X— ^_ /jW ±j=%~?=j K^±;j [_=

~>/_X?jWh

v? ~±Wj± /~ ±j%±~W^Kj /' j j]%j±X—j?/_ W _ /_ * [j !~^?W /' _ / /'j _ / /j ? ^ _ / X~ ? j?J/'

'_W _ %~[j±E_[ Wj%j?Wj?Kj ~? /'j W~=j j;j=h v? ±_W X_ /X~? '_±W?j== = /^W Xj= ~ ! %_=/XK

=KX?/X_/X?J !X>j±=* /'j _ / /j ? ^ _ / X~ ? j?J/' [_= !~^?W /~ >j _ X?j_± !^?K/X~? ~! /'j

±jKjX;jW W~=j Tw*h uhu [ X /' * f s'h v? /'j * ^ _ ± /\ !X>j±= ^=jW X? /'X= = /^W° * '~[j;j±*

X/ /^±?jW ~ ^ / /' _ / _ %~[j±E_[ Wj%j?Wj?Kj —~±j _KK^±_ /j ° Wj=K±X>jW /' j W_ /_ h

BXJ^±j uhn ='~[= /'j ±j=^ /= ~ ! /'j =X— ^_/X~?= Wj=K±X>jW _>~;j [ 'j? _ ;_^j ~!

* f s X= ^=jWh 4 'j = X— ^ _ /jW K^±;j= j]'X>X/ /'j =_—j K'_±_K/j±X= /XK !j_ /^±j= _= /'j

j]%j±X— j?/_ W_ /_ e _ — ~±j ~ ± j== !_/ ±j=%~?=j !~± KE;_^j= _±Jj± /'_? EO K—* ['j±j

/'j ±_W X_/X~? j!!jK/= >jK~— j ?jJXJX>° =—_ _?W _ —~±j ~ ± j== ~J_±X/'— XK WjKX?j ~!

/'j ±j=%~?=j !~± XJ'/ % ±~ W ^ Kj W X? /'j _!!jK/jW ±jJX~? ~! /' j K_~±X—j/j± ° C d EO K—'h

B±~— /'j ~>=j±;jW ± EWj%j?Wj?Kj X? /'j !X±=/ ms K— X? /'j !XJ^±j* ~?j [~^W K~?K^Wj

/' _ / 3~ _ — ~ ^ ? /= /~ Tn # u' ■ FO\1 - ±_W< K — < h q~[j;j±* !~± =^K' _ ;_^j ~! 3~* /'j

9X?9 =j%_±_ /X?J /'j C ±_? J j ~ ! !_/ ±j=%~?=j _?W /'j C ±_?Jj _!!jK/jW >° /' j ±_WX_/X~?

us


\Vith this modeL simulated response curves (.:-scans) were obtained as follows.

The Cerenkov light produced at a certain depth z and trapped inside the fibers was

split into two components, with equal fractions going to the right ( +.:, straight to the

Pl\lT) and to the left ( -i, to the aluminized front end of the fibers). The photons

in both components were tracked in steps of 0.5 cm on their way through the fiber.

In every step. the light intensity was diminished by a factor exp[-0.5/l(z')J, with the

local attenuation length l(z') at depth ::' expressed in cm. Light traveling to the left

(-:, see Figure -1.1) was assumed to undergo an intensity loss of 20% upon reflection

off the mirrored fiber end. The value of l0 was taken as 20 m. Both numbers were

based on results of measurements \vith an unirradiated module of exactly the same

composition [9J. In this \Vay, the fraction of the Cerenkov light trapped in the fibers

that reached the P~IT was calculated. By repeating the described procedure for

a large number of points at different depths (.:), the simulated response curve was

obtained.

In order to reproduce the experimental data, we found that the attenuation length

had a power-law dependence on the dose levels. In radiation hardness studies of plastic

scintillating fibers, the attenuation length was found to be a linear function of the

received dose (Eq. 4.-l with n = 0). In the quartz fibers used in this study, however,

it turned out that a power-law dependence more accurately described the data.

Figure 4.3 shows the results of the simulations described above when a value of

n = 0 is used. The simulated curves exhibit the same characteristic features as the

experimental data: a more or less flat response for .:-values larger than 20 cm, where

the radiation effects become negligibly small and a more or less logarithmic decline of

the response for light produced in the affected region of the calorimeter (z < 20 cm).

From the observed z-dependence in the first 10 cm in the figure, one would conclude

that a0 amounts to (3 - 4) · 10-4 ivirad- 1cm- 1• However, for such a value of no, the

kink separating the :: range of flat response and the .: range affected by the radiation

40

W~=j _%%j_±= /~ >j ~K_/jW Wjj%j± X?=XWj /'j Wj/jK /~± /' _? /'j =X— ^_/X~?= j_W ^= /~

>jXj;j SE EO K— j]%j±X—j?/_°* _1B C Y FO K— X? /' j =X—^_/X~?='h

shp

[d

U w]%j±X—j?/_ W_/_h l f s E c ——

© _ f n ms u - ? ^ q K — Am

OCEms mc as ac nsO

, j%/' X? K_~±X— j/j±* \ TK— '

BXJ^±j uhne ZX—^_/jW ±j=%~?=j K^±;j= >_=jW ~? w*^_/X~? uhu _?W /'j W~=j %±~!Xj y°C{ _KK^—^_/jW X? /'j 6 X?/j±;_ sEc —— !~± ? f s _?W WX!!j±j?/ ;_^j= ~! /'j %_±_—j/j± _h B~± K~—%_±X=~?* /'j j]%j±X—j?/_ EE±j=%~?=j K^±;j !~± ° f s # c ——* K~?;j?Xj?/° ?~±—_X\jW* X= ='~[? _= [jh Zjj /j]/ !~± Wj/_X=h

6 'j? [j ±j%j_/jW /' X= _?_°=X= T[X/' * f s' !~± ~ /' j ± ±jJX~?= X? ['XK' EE=K_?=

' _ W >jj? %j±!~±—jW TXhjh* !~± WX!!j±j?/ °E=XKj=* ['j±j /'j X?W^KjW W~=j= [j±j —^K'

=—_j±'* [j !~^?W /' _ / K~?=XWj±_>° _±Jj± ;_^j= ~ ! 3~ [j±j ?jjWjW /~ Wj=K±X>j /'j

— j_=^±jW ±j=%~?=j K^±;j=h x?W* _= >j!~±j* /'j = X— ^_/X~?= T[X/' * f s' [j±j ~?°

K_%_> j ~! ±j%±~W^KX?J /'j C Wj%j?Wj?Kj X? /'j !X±=/ % _ ± / ~! /'j Wj/jK /~ ± * ['j±j_=

/' j j]%j±X—j?/_ j!!jK/= ~ ! /'j X?W^KjW ±_WX_/X~? j] /j?WjW —^K' Wjj%j± X?=XWj /'j

K_~±X— j/j±h

4'X= jW ^= /~ >jXj;j /' _ / X? ~±Wj± /~ _Wj*^_/j° Wj=K±X>j /'j j]%j±X— j?/_ W _ /_

!~± *^_±/\ !X>j±=* mixT\' X= ?~/ _ X?j_± !^?K/X~? ~! W~=j* > ^ / _ !^?K/X~? ~! =~—j %~[j±

~! /'j W~=jh BXJ^±j uhu ='~[= /'j ±j=^/= ~! =X—^_/X~?= %j±!~±—jW [X/' ;_±X~^= ;_^j=

um


dose appears to be located deeper inside the detector than the simulations lead us to

believe (.:: ::::: 20 cm experimentally, vs. ;; ::::: 10 cm in the simulations) .

1J :r. 0.7 ~

~

;;-~ ... 0.5 ~

~ "§

"' 0.3

. . . .lA.~······ ;! ~· ,•:;

............. , ..................... ! • I • • • •••• I ................ .

: ••• ; : ~ ~ 1 ;, :: : : : :: ,J J J •) :: .: : = ; :: : ; .., . ~ : • ~ J -

l •

• fapcnmc:ntal data. } = 0 • 5 mm

a = 3 10 •4 '.\(rJJ· 1crn· 1

• a = ~ · I0 . 4 '.\lrad· 1,m· 1

a = 5 · IO •4 \traJ· 1 cm· 1

0.2 '------------------------' 0 5 10 15 20 25 30

Depth in calorimeter. z ( cm)

Figure -l.3: Simulated response curves based on Equation -1.4 and the dose profile D( z) accumulated in the y interval 0-5 mm for n = 0 and different v-J.lucs of the parameter a. For comparison, the experimental z-response curve for y = 0 - 5 mm, conveniently normalized, is shown ~ well. Sec text for details.

\Vhen we repeated this analysis (with n = O) for other regions in which z-scans

had been performed (i.e., for different y-slices, where the induced doses were much

smaller), we found that considerably larger values of o:0 were needed to describe the

measured response curves. And, as before, the simulations (with n = 0) were only

capable of reproducing the z dependence in the first part of the detector, whereas

the experimental effects of the induced radiation extended much deeper inside the

calorimeter.

This led us to believe that in order to adequately describe the experimental data

for quartz fibers, 1/ ,\(z) is not a linear function of dose, but a function of some power

of the dose. Figure 4.4 shows the results of simulations performed with various values

41

~! _~ _?W *B v? /'j=j =X—^_/X~?=* /'j ;_^j ~! * Wj/j±—X?j= /'j ~K_/X~? X? Wj% /' ~!

/'j 9X?9h 4 ' j ;_^j ~! * O Wj/j—X?j= /'j =~%j ~! /'j ±jJX~? X? !±~?/ ~! /'j 9X?9 X?

Kh 4'j >j=/ ±j%±~W^K/X~? ~! /'j j]%j±X—j?/_ %~=X/X~? ~! /'j 9X?9 T_/ C < a s K—' [_=

!~^?W !~± * f shp* _?W /'j K~±±j=%~?WX?J ~% /X— ^— ;_^j ~! * O [_= shsmsh

shb

OC0F i . ~shp

x U

'Ej

■ j]%j±X— j?/_ W_/_ q q m shssr , A“ c j _ f shsms ,E|E♦h _ f shsmu , ®

shn5

OCEmc EO ac ns ncmsO

C TK— '

BXJ^±j uhue ZX—^_/jW ±j=%~?=j K^±;j= >_=jW ~? w*^_/X~? uhu _?W /'j W~=j %±~!Xj y°C{ _KK^—^_/jW X? /'j 6 X?/j±;_ sEc —— !~± WX!!j±j?/ ;_^j= ~! /'j %_±_—j/j±= ? _?W qB B~± K~—%_±X=~?* /'j j]%j±X—j?/_° —j_=^±jW K^±;j X= ='~[? _= [jh Zjj /j]/ !~± Wj/_X=h

4'j !_K/ / ' _ / FixTE' X= _ !^?K/X~? ~! =~—j %~[j± ~! /'j W~=j —j_?= /' _ / ±j_/X;j°

=—_ W~=j= ~! ±_WX_/X~? K_^=j ±j_/X;j° _±Jj j!!jK/= ~! X?W^KjW XJ'/ _ //j?^_/X~? h

x/ W~=j= ~! _ !j[A —jJ_±_W=* /'j ±_WX_/X~? '_±W?j== X= ?~/ —^K' >j//j± /' _? /' _ / ~!

/'j >j=/ % _=/XK =KX?/X_/~±= DFOV* >^ / _ / — ^K' 'XJ'j± W~=j= /'j ±_WX_/X~? '_±W?j== X=

K~?=XWj±_>° >j //j ± h

ua


of a 0 and n. In these simulations, the value of n determines the location in depth of

the kink. The value of a 0 detemines the slope of the region in front of the kink in

;;. The best reproduction of the experimental position of the kink (at z ~20 cm) was

found for n = 0. 7, and the corresponding optimum value of a 0 was 0.010 .

1.0

0.9

0.8

- 0.7 :::: ~

..._... 0.6 ~ V: c:: 5,. 0.5 ;r,

~

~ O.~ ~

2 ·.::: C

Ci 0.3

0

•

0 •

• experimental data a a = 0.006 o·0 ·5

0 a= 0.010 0·07

• a= o.Ol-4 o-o.s;!

0.2.___ .......... __ .___....._ __ .__ _ __._ __ .___ ........ _ ___, 0 5 10 15 20 30 35

z (cm)

Figure 4.4: Simulated response curves based on Equation 4.4 and the dose profile D(z) accumulated in the y interval 0-5 mm for different V'J.lues of the parameters n and a. For comparison, the e..,:perimentally measured curve is shown as well. See text for details.

The fact that l / A( z) is a function of some power of the dose means that relatively

small doses of radiation cause relatively large effects of induced light attenuation.

At doses of a few megarads, the radiation hardness is not much better than that of

the best plastic scintillators [10], but at much higher doses the radiation hardness is

considerably better.

42

g q x L 4 w 0 c

gx )vy 0 x 4vP k )Q P k v48 , vP x ))2 Z w k - w P 4 w , g x ) Q 0 v- w 4 w 0 Z

g _X>±_ /X?J _ K_~±X— j/j± X= _ /±XK9° >^=X?j==h v? /' X= K'_%/j±* =~—j ~! /'j =^>E

/j/Xj= ~! K_ ~ ±X— j/j± K_ X> ±_ /X~? _±j _WW±j==jWh

chm g , B L^J 8 %J±_Wj g_~±X— j/j±

4'j _?_°=X= WX=K^==jW X? /'j ?j]/ =jK /X~? [_= K_±±XjW ~^/ [X/' /j = />j_— W _ /_

!±~— /'j ?j[ j?W%^J K_ ~ ±X— j/j± ~! /'j g ~ XWj± ,j/jK/~± _ / Bj±—X_> Tg , B 'h 4'X=

K_~±X— j/j± =°= /j— [_= —~WX!XjW _= %_±/ ~ ! /X?. ^%J±_WjF % ±~J±_— X? % ±j%_±_ /X~? !~±

0^? vv _/ /'j 4j;_/±~?h v/ K~;j±= /'j %=j^W~±_% XW X/° ±_?Jj !±~— FCF E nhk _?W ±jE

%_Kj= /'j ~±XJX?_ J_=E>_=jW K_~±X—j/j±h 4 ' j ?j[ Wj/jK /~ ± K~?=X=/= ~! _ shpcxXD/ Wjj%

jjK/±~— _J?j/XK Tw-' =jK/X~? _?W _ phuxX?/ Wjj% '_W±~?XK Tqx,' =jK/X~?h 4 'j jjKE

/±~— _J?j/XK =jK/X~? X?X= _ j_W i=KX? /X _ /~ ± =_?W[ XK' = /±^K /^ ±j * [X/' uhc — — /'XK9 j_W

%_/j= _ /j ±?_ /jW >° uhs — — /'XK9 %_=/XK =K X? / X _ /~ ± %_/j=h v? /'j '_W±~?XK =jK/X~?h

rhs —— /'XK9 =K X? /X _ /~± %_/j= _±j =_?W[XK'jW >j/[jj? csht — — /'XK9 X±~? _>=~±>j±

%_/j=h 4'j =XJ?_= _±j ±j_W ~^/ >; —j_?= ~ ! [_;jj?J/' =' X!/X?J ~%/XK_ !X>j±=* ['XK'

_±j j—>jWWjW X? /'j =K X? /X _ /~± %_/j=h 4 ' j j jK /±~— _J?j/XK _?W '_W±~?XK =jK/X~?=

_±j >~/' ?~?K~— %j?=_ /X?J Wj;XKj= [X/' — \ > ;_^j= ~! mhun _?W mhnrh ±j=%jK/X;j°h

- ~±j Wj/_X= _ > ~ ^ / /'X= Wj;XKj _±j JX;j? X? 0j!j±j?Kj DFFV*

cha g , B L^J 8 %J±_Wj /j = />j_— _?_°=X=

B X?WX?J /'j K~±±jK/ j?j±J° =K_j ~! _ K_ ~ ± X— j /j ± ['XK' X= WX;XWjW X?/~ _? jjK/±~E

— _J?j/XK _?W _ '_W±~?XK =jK/X~? X= ?~/ /±X; X_ DmaVh 4'j j?j±J° =K_j X= /'j K~?=/_?/

['XK' K~?;j±/= /'j =XJ?_ !±~— /'j K_~±X— j/j± /~ ^?X/= ~! j?j±J°h v! _ K_~±X— j/j± X=

~?JX/^WX?_° W X; XWjW X?/~ /[~ =jK/X~?= [ X/' WX!!j±j?/ — _/j±X_ K~—%~=X/X~?=* /'j? _?

j?j±J° =K_j X= ?jjWjW !~± j_K' =jK/X~? =j%_±_/j°h

un


CH.-\PTER 5

C.-\LIBR..\TL\.G LO:\GITCDIX.-\LLY SEG~IE:'-iTED C..\LORnIETERS

Calibrating a calorimeter is a tricky business. In this chapter, some of the sub

tleties of calorimeter calibration are addressed.

5.1 CDF Plug Cpgrade Calorimeter

The analysis discussP<l in the next section was carriPd out with testbeam data

from the IH'W endplug calorimeter of the Colli<ler Detector at Fermilab (CDF). This

calorimeter system was modified as part of the upgracfr program in preparation for

Run fl at the Tt>\·atron. It con-rs the pseudorapidity rauge from 1. 1 - 3.G and rP

places the original gas-b,Lo.;ed calorimeter. The new detector consists of a 0. 75,\nt deep

electromagnetic (E~i) section and a i.-L\nt deep hadronic (H.-\D) section. The rlrc

tromagnetic section has a lead/scintillator sandwich structtm'. with -L5 mm thick lead

plates alternated by -LO mm thick plastic scintillator plates. In the hadronic section.

6.0 mm thick scintillator plates are sandwiched between 30.8 mm thick iron absorber

plates. The signals are read out l,y means of wavelength shifting optical fibers. which

are embedded in the scintillator plates. The electromagnl'tic and hadronic sections

are both noncompensating devices with e / h val11es of 1.-13 and 1.36. respect.iYely.

~lore details about this device are given in Reference [l 1].

~ •) .J __ CDF Plug Cpgrade testbearn analysis

Finding the correct energy scale of a calorimeter which is divided into an electro

magnetic and a hadronic section is not trivial [12]. The energy scale is the constant

which converts the signal from the calorimeter to units of energy. If a calorimeter is

longitudinally divided into two sections with different material compositions. then an

energy scale is needed for each section separately.

-13

4 ' j j?j±J° =K_j ~ ! _ K_~±X— j/j± X= T_/ j_=/ X? X/X_ ° ' W j /j ±— X? jW !±~— _ /j = / E

> j_— ~! %_±/XKj= ~! /' j /°%j /' _ / /' j K_ ~ ±X— j/j ± [X — j_=^±j [ X/' _ [j Wj!X?jW

j?j±J°h Z^K' _ >j_— X= =j? / X?/~ /'j K_~ ±X— j/j±* _ ? W /' j ±_/X~ ~ ! /' j =XJ?_ !±~— /' j

K _ ~ ±X— j /j ± Tx,g K~^? /=' [X/' /'j j?j±J° ~! /'j X?K~— X?J %_ ±/XK j= Tkj1' X= Wj!X?jW

_= /' j j?j±J° =K_jh v? — ~=/ ~?J X/^W X?_° =jJ— j? /jW K_ ~ ±X— j/j ± =°=/j— =* W j /j ± E

— X? X? J /'j j?j±J° =K_j ~ ! /'j j jK/±~— _J?j/XK =jK /X~ ? X= = /±_ XJ ' /!~ ±[ _±W =X?Kj /' j

j jK /±~ — _J ? j /XK =jK/X~? X= Wjj% j?~^J' /~ !^° K ~ ? /_ X? /'j ='~[ j± !±~— _? X?K~— X?J

j jK /±~? h x /j=/>j_— ~ ! jjK/±~?= X= =j? / X?/~ /'j j jK /±~— _J?j/XK =jK/X~? _?W /'j ±_ /X~

~ ! /' j =XJ?_ !±~— /'j j jK/±~— _J?j/XK =jK/X~? Tx , g K~^?/=' [ X/' /'j j?j±J° ~ ! /' j

X?K~— X?J jjK/±~?= Tk j1 ' X= Wj!X?jW _= /'j j?j±J° =K_j !~± /' _ / =jK/X~? h , j/j±— X? X?J

/' j j?j±J° =K_j ~! /'j '_W±~?XK =jK/X~?* '~[j;j±* X= /±XK9°h v? — ^=/ K_~±X— j/j± =°=E

/j— = [ X/' /[~ ~?J X/^W X?_ =jJ— j?/=* '_W±~?= W j % ~ = X/ /'j X± j?j±J° X? 9£N> =jJ— j?/=h

6j '_;j = /^W XjW /'±jj — j/'~W= /~ Wj /j ±— X?j /' j j?j±J° =K_j ~ ! /'j '_W±~?XK =jKE

/X~? ^=X?J j]%j±X— j? /_ W _ /_ /_9j? [ X/' _ =%jKX_ — ~W^ j ~! /'j g , B L^J 8 %J±_Wj

g _ ~ ±X— j /j ± /' _ / [_= > ^ X/ !~± /j=/>j_— %^±%~=j=h 4 ' X= — ~W^j K~?=X=/= ~! !~^± mcf

=jK/X~?= ['XK' _±j ±j% XK_= ~! /'j _ K /^ _ L ^J 8♦% J ±_W j K_ ~ ±X— j/j± T=jj BXJ^±j c hm 'h

Q ?j ~ ! /'j=j !~^± [jWJj= [_= >^X/ [ X/'~^ / _? w- K~ — % _±/— j? /h 4 ' j ±j=^/= ~! /' X=

= /^ W ° [j±j %^>X='jW X? lR5]—q0 [*1N0RS —* N1 q*% , —N>£%1 <* k>61<51 I—1—q05>B qj±j*

[j =^ — — _±X\j /'j — ~=/ X— % ~ ±/_? / ±j=^ /= _?W ±j!j± /~ x %%j?WX] y !~± Wj/_X=h

chahm 4 'j K_ X> ±_ /X~? — j/'~W=

c hE h FCF w jK /±~— _J?j/XK =jK/X~? j?j±J° =K_j

x /' ~ ^ J ' [j WX=K^== /' ±jj WX!!j±j?/ — j/'~W= ~ ! W j /j ±— X? X?J /' j j?j±J° =K_j ~ !

/'j ' _W ±~ ? XK =jK/X~?* [j ~?° ^=jW ~?j — j/'~W /~ Wj/j±— X?j /' j j?j±J° =K_j ~ !

/'j j jK /±~— _J?j/XK =jK/X~? h 4'j j?j±J° =K_j ~ ! /' j j jK /±~— _J?j/XK =jK/X~?* } ■

[_= W j /j ±— X? jW [ X/' > j_— = ~! jjK/±~?= T±_?J X?J !±~— tEmts k j1 ' =j?/ X?/~ /' j

j jK /±~ — _J ? j /XK =jK/X~?h B XJ^±j cha ='~[= /'j ;_^j ~ ! x _= _ !^?K/X~? ~! /'j jjK/±~?

uu


The energy scale of a calorimeter is (at least initially) determined from a test

beam of particles of the type that the calorimeter will me~ure with a well defined

energy. Such a beam is sent into the calorimeter, and the ratio of the signal from the

calorimeter (.-\DC counts) with the energy of the incoming particles (Ge\") is defined

as the energy scale. In most longitudinally segmented calorimeter systems, deter

mining the energy scale of the electromagnetic section is straightforward since the

electromagnetic section is deep enough to folly contain the shower from an incoming

electron .. -\ test beam of electrons is sent into the electromagnetic st~ction and the ratio

of the signal from the electromagnetic section (.-\DC counts) with the energy of the

incoming electrons (Ge\") is definPd as the energy scalt• for that section. Determining

thP energy scalt• of thP haclronic section. howevPr. is tricky. In must ealorimett•r sys

tems with two longitudinal segments. hadrons dt•posit ttwir enngy in both segment:;.

\\"e hm·e studied three methods to detnmir1t• the energy scale of the haclronic sec

tion using experimental data taken with a special module of the CDF Plug L"pgrade

Calorimeter that was built for testbeam purposes. This module consists of four 15c

sections which are replicas of the actual Plug Cpgra<le calorimeter (see Figure 5.1).

One of these four wedges was built without an E.\I compartment. The results of this

study were published in j\/uclear Instruments and Aletlwds in Physic:; lfrsearch. Here.

we summarize the most important results and refer to .-\ppendix 8 for details.

5.2. l The calibration methods

5.2.1.1 Electromagnetic section energy scale

. ..\.lthough we discuss three different methods of determining the energy scale of

the hadronic section. \Ve only used one method to determine the energy scale of

the electromagnetic section. The energy sea.le of the electromagnetic section, A,

was determined with beams of electrons ( ranging from 8-180 Ge V) sent into the

electromagnetic section. Figure 5.2 shows the value of A as a function of the electron

-l-l

FOO=K_j TK—'

6jWJj m

BXJ^±j chme 4'j L^J 8%J±_Wj /j=/>j_X? —~W^j K~?=X=/jW ~! !~^± mcn =jK/X~?=* j_K' [X/' as /~[j±=h 6jWJj n [_= >^X/ ^<N>£RN _? w- =jK/X~?h

>j_— j?j±J°h 4 ' j ;_^j ~! hu X= K~?=/_? / [X/'X? j]%j±X— j?/_ ^?Kj±/_X? /Xj= ~;j± /' X=

j?j±J° ±_?Jjh 4 ' j [jXJ'/jW _;j±_Jj [_= !~^?W /~ >j hu f mathm K~^?/=ik j1 h

chE hFCE q_W±~?XK =jK/X~? j?j±J° =K_j# - j/'~W v

v? /'X= — j/'~W * _ >j_— ~! %X~?= [ X/' _ [j Wj!X?jW j?j±J° X= =j?/ X?/~ /'j jjKE

/±~— _J?j/XK =jK/X~? ~! /'j K_ ~ ±X— j/j± T[X/'* ~! K~^±=j* /'j '_W±~?XK =jK/X~? W X±jK/°

>j'X?W X/'h L X~?= ['XK' %_== /' ±~^J' /'j jjK/±~— _J?j/XK =jK/X~? [ X/'~^ / ^?Wj±J~X?J

_ ?^Kj_± X? /j±_K /X~? T N%j?j/±_ /X?J %X~?=£ ' _±j =jjK/jWh B~± ~?° /'~=j %j?j/±_/X?J

%X~?=* /'j ±_/X~ ~ ! /'j =XJ?_ !±~— /'j '_W±~?XK =jK/X~? Tx,g K~^?/=' [X/' /'j j?j±J°

~! /'j X?K~— X?J %X~?= Tkj1' X= Wj!X?jW _= /'j j?j±J° =K_j ~! /'j '_W±~?XK =jK/X~?h L XE

~?= [ X/' j?j±JXj= ±_?JX?J !±~— tEmrs kj1 [j±j ^=jW /~ !X?W /'j ;_^j ~! /'j '_W±~?XK

=jK/X~? j?j±J° =K_j oU [X/' /' X= — j/'~Wh BXJ^±j chn ='~[= /'j ;_^j ~! o N _= _ !^?KE

/X~? ~! /'j j?j±J° Wj%~=X/jW X? /'j '_W±~?XK K_~±X— j/j± =jK/X~? >° /'j %j?j/±_/X?J

%X~?=h P~/j /'j ~J_±X/'— XK =K_j ~! /'j '~±X\~?/_ _]X=h 8?X9j hu* /'j ;_^j ~! oU X=

Kj_±° j?j±J°EWj%j?Wj?/h 4'X= X= /'j — j/'~W g,B '_= /±_W X/X~?_° ^=jW /~ K_X> ±_/j

uc


0 20 60 80 100

scale (cmJ

Wedge I

Wedge 2 --------

Figure 5.1: The Plug l:pgradc tcstbeam module consisted of four 15~ sections, each with 20 towers. Wedge :3 was built without an EM ~ection.

beam energy. The value of .-l is constant within experimental uncertainties over this

energy range. The weighted average was found to be .-l = 128. l counts/GeV.

5.2. 1.2 Hadronic section energy scale-~Iethod I

In this method, a beam of pions with a ·well defined energy is sent into the elec

tromagnetic section of the calorimeter ( with, of course, the hadronic section directly

behind it). Pions which pass through the electromagnetic section without undergoing

a nuclear interaction ( "penetrating pions") are selected. For only those penetrating

pions, the ratio of the signal from the hadronic section ( . .\DC counts) with the energy

of the incoming pions (GeV) is defined as the energy scale of the hadronic section. Pi

ons with energies ranging from 8-160 GeV were used to find the value of the hadronic

section energy scale Bi with this method. Figure 5.3 shows the v-alue of B1 as a func

tion of the energy deposited in the hadronic calorimeter section by the penetrating

pions. :'-lote the logarithmic scale of the horizontal axis. Unlike A., the value of B1 is

clearly energy-dependent. This is the method CDF has traditionally used to calibrate

45

mac E

X

mas E

v v

mmc EEEEEEEEmEEEEEEEEe# ©# ©# IEEEEEE eEEEEEEEE EE# # ■s as us rs ts mss mas mus mrs mts

5*k]~D S3ks'

BXJ^±j chae 4'j j?j±J° =K_j !~± /'j w- K_~±X—j/j± =jK/X~?h huh U \ P _ !^?K/X~? ~! j?j±J°*

/' j '_W±~? XK K_~±X— j/j± =jK/X~?h

chahmhn q _W±~?XK =jK/X~? j?j±J° =K_j# - j/'~W vv

v? /' X= — j/'~W * /'j K_ X> ±_ /X~ ? K ~ ? =/_? /= ~! >~ /' K_ ~ ±X— j /j ± =jK/X~?= _±j j=/_>E

X='jW [ X/' /'j =_— j /°%j ~ ! %_±/XKj=h 4 'j ^?Wj±° X?J %'X~=~%'° ~ ! /' X= — j/'~W

X= /' _ / /' j ±j_ /X~?='X% >j/[ jj? W j%~=X/jW j?j±J° _ ? W ±j=^ /X?J K_ ~ ±X— j /j ± =XJ?_

='~^ W >j j=/_>X='jW X? /' j =_— j [_° !~± _ =jJ— j?/= ~ ! /' j K_ ~ ±X— j/j± =°=/j— h v?

~ ^ ± K_=j* [j ^=jW _ >j_— ~! ' XJ'Ej?j±J° jjK/±~?=* =j? / W X±jK /° X?/~ /' j '_W±~?XK

K_ ~ ±X— j/j ± =jK/X~?* /~ /j = / /' j — j±X/= ~ ! /' X= — j/'~W h v? %±_K/XKj /' X= — j/'~W X=

^=^_° X— %~==X>j /~ X— %j— j?/ X? _? j]%j±X— j?/* =X?Kj /' j qx, =jK/X~? X= ='XjWjW

!±~— /'j %_±/XK j =~^±Kj TXhjh* /'j X? /j ±_K /X~ ? ±jJX~?' >° /' j w- =jK/X~?h q~[j;j±*

ur


---;;., ~

c.; 3 .,:. <

135

l i

130 ;-

• • .. • • I

125 ~

120 ~

115 ---'-----------~-----~~-0 20 ~o 60 so 100 120 uo t6o 1so

Energy (GeV)

Figure 5.:2: The energy scale for the E.\f caloriuwter section. A. as a function of energy.

the hadronic calorimeter section.

5.2. 1.3 Hadronic section energy scale-~Iethod II

In this method. the calibration constants of both calorimeter sections are estab

lished with the same type of particles. The underlying philosophy of this method

is that the relationship between deposited energy and resulting calorimeter signal

should be established in the same way for all segments of the calorimeter system. In

our case. we used a beam of high-energy electrons. sent directly into the hadronic

calorimeter section, to test the merits of this method. In practice this method is

usually impossible to implement in an experiment. since the H . ..\D section is shielded

from the particle source (i.e., the interaction region) by the E.\I section. However,

-16

] nk■,^J 2R •k*k■]c■p*~ •p^*’

mrs

X

mus E

masms msN

5*k]~D S3ks'

BXJ^±j chne 4'j j?j±J° =K_j ~! /'j '_W±~?XK =jK/X~?h oUB !~^?W ^=X?J - j/'~W v _= _ !^?K/X~? ~! /'j j?j±J° Wj%~=X/jW X? /'j '_W±~?XK =jK/X~? ~! /'j K_~±X— j/j± >° %j?j/±_/X?J %X~?=h

X? ~^± /j = /> j _ — =j /^% [j K~^W = /^ W ° /' X= — j/'~W /' _? 9 = /~ /'j !_K/ /' _ / %_±/ ~!

/'j /j = /jW K_ ~ ±X— j/j± [_= *£N j*^X%%jW [ X/' _? w- =jK/X~? h w jK/±~?= [ X/' j?j±JXj=

±_?JX?J !±~— mmEmpp kj1 [j±j ^=jW /~ !X?W /'j ;_^j ~ ! /'j '_W±~?XK =jK/X~? j?j±J°

=K_j oUUB [ 'XK' X= ='~[ ? _= _ !^?K/X~? ~ ! /'j j jK /±~? j?j±J° X? B XJ^ ±j chuh y ii X=

K~?=/_? /h mpnhc K~ ^ ? /= ik j1 * !~± _ [XWj ±_?Jj ~! j jK /±~? j?j±JXj=h

chahmhu q _W±~? XK =jK/X~? j?j±J° =K_j# - j/'~W vvv

v? /' X= — j/'~W * ['XK' /~ ~^± 9?~[jWJj '_= ?~ / ° j / >jj? _%% XjW X? _?° ~ /'j±

j]%j±X— j? /* %X~?= [ X/' _ [jEWj!X?jW j?j±J° _±j ^=jW /~ X? /j ±K_ X> ±_ /j /' j w- _?W

qx, K_ ~ ±X— j /j ± =jK/X~?=h 4 'j K_ X> ±_ /X~? K~?=/_? / !~± /'j w- =jK/X~? X=h _= ^=^_h

up


r I

uo -

Method I, penetrating pions

120 ------------------'-----~

10 10·

Energy (Ge\')

Figure 5.3: The cner1,,ry scale of the hadronic section. B1. found usin~ ~Iethod I as a. function of the energy deposited in the hadronic section of the calorimeter by penetrating pious.

lil our testbeam setup we could study this method thanks to the fact that part of

the tested calorimeter Wcl.') not equipped with an E~I section. Electrons with energies

ranging from 11-177 GeV were used to find the value of the hadronic sPction energy

scale Bu. which is shown as a function of the electron energy in Figure 5.-t B11 is

constant, 173.,5 counts/Ge\·. for a wide range of electron energies.

5.2.1..l Hadronic section energy scale-~Iethod III

In this method. which to our knowledge has not yet been applied in any other

experiment, pions with a '"·ell-defined energy are used to intercalibrate the E~I and

H.--\O calorimeter sections. The calibration constant for the E?\[ section is. as usual.

-!7

E EOO EEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEElG i nk■,^J 22R k>ky■]^*’ p* ,cJ

v

mts E

mrs E

as us rs ts mss mas mus mrs mts

5*k]~D S3ks'

BXJ^±j chue 4'j j?j±J° =K_j ~ ! /'j '_W±~?XK =jK/X~?h o * B !~^?W ^=X?J -j/'~W vv _= _ !^?K/X~? ~! /'j j?j±J° ~! /'j X?K~—X?J jjK/±~?=h

Wj /j ±— X?jW [ X/' j jK/±~?= ~! 9?~[ ? j?j±J°* [ 'Xj /' j K_ X> ±_ /X~ ? K~?=/_? / !~± /'j

qx , =jK/X~? X= K'~=j? =^K' /' _ / /' j _;j±_Jj j? j±J ° ±jK~ ? =/±^ K /jW !~± % j? j /±_ /X? J

%X~?= X= j*^_ /~ /' _ / !~± ? ~ ? % j ? j /±_ /X? J %X~?=h

4 ' j ^?Wj±° X?J %'X~=~%'° ~! /' X= — j/'~W X= /~ _;~XW _?° Wj%j?Wj?Kj ~ ! /'j

±jK~?=/±^K /jW T'_W ±~? XK' j?j±J° ~? /' j = /_ ± /X? J % ~ X? / ~! /'j ='~[ j±=h x= [j [X =jj

_ /j ±* =^K' _ Wj%j?Wj?Kj X= _? X?j; X/_> j K~?=j*^j?Kj ~! /'j _% % XK_ /X~ ? ~! - j/'~W

vh )A?X9j - j/'~W vvh /' X= — j/'~W 'X/= /'j _ W ; _ ? /_ J j /' _ / X/ K_? >j X— %j— j?/jW X?

% ±_K /XKj _?W /' _ / X/ K_? >j _% % XjW <* 1<NR ^ = X? J ±jK~ ? =/±^ K /jW /±_K9= ~! X=~ _/jW

%_ ±/XK j= %±~W^KjW X? /'j X? /j ±_K /X~ ? = =/^W XjW >° /' j j]%j±X— j?/h

v? ~ ±W j± /~ _;~XW /' j j!!jK/= ~ ! ='~[ j± j_9_Jj* [j ^=jW =j;j±_ ~[ j?j±J° Td a s

ut


~ ~ ... ~ ~ '-'

=-

200 ,.---------------------I

r

i 180 -

i

160 :..-

•

Method II, electrons in had

• •

20 .ao 60 80 100 120 uo 160 180

Energy (Ge\')

Figure 5.--l: The energy scale of the hadronic section. Bn. found using 1Iethod II a.-; a function of thP energy of the incoming electrons.

determined with electrons of known energy, while the calibration constant for the

H.-\D section i-; chosen such that the average energy reconstructed for penetrating

pions is equal to that for nonpenetrating pions.

The underlying philosophy of this method 1s to avoid any dependence of the

reconstructed (hadronic) energy on the starting point of the showers. As we will see

later, such a dependence is an inevitable consequence of the application of .\Iethod

I. C'nlikc :\Iethod II. this method has the advantage that it can be implemented in

practice and that it can be applied in situ using reconstructed tracks of isolated

particles produced in the interactions studied by the experiment.

In order to avoid the effects of shower leakage, 1,ve used several low energy ( <20

--18

kj1' % X~? ±^?= /~ !X?W /' j ;_^j ~! /'j '_W ±~ ? XK =jK/X~? j?j±J° =K_j o < * ^=X?J /' X=

— j/'~W h 6j !~^?W _? _;j±_Jj ;_^j o R < f mtr hc K~ ^ ? /= ik j 1 h

chaha w ] % j±X— j? /_ K~?=j*^j?Kj= ~! j_K' — j/'~W

4 ' j ±jK~?=/±^K /jW j?j±J° X= Wj!X?jW _=

5 A w- =XJ?_ Tx,g K /= ' G qx, =XJ?_ Tx,g K /= ' N A Yy ±jK~ ? # v N' # T Q E '

~P.W..B...

['j±j } X= /'j j?j±J° =K_j ~ ! /'j j jK/±~— _J?j/XK =jK/X~? _?W c i h i i h i i i Wj?~/j= /'j

j?j±J° =K_j ~! /'j '_W±~?XK =jK/X~? _KK~±W X?J /~ - j/'~W vhvvh ~± vvvh

v! [j K'~=j - j/'~W v /~ =j / /'j j?j±J° =K_j ~! /'j q x , =jK/X~?* [j [~^W ?jjW

/~ =%jKX!° /'j j?j±J° _/ ['XK' /'j K_ X> ±_ /X~? K~?=/_? / oU [_= Wj /j ±— X?jW * =X?Kj /'X=

;_^j X= j?j±J° Wj%j?Wj? /h , j%j?WX?J ~? /' j j?j±J°* /' j ;_^j ~! o : — _° K'_?Jj >°

_= — ^K' _= msb!eh 4 'j ~ /' j± /[~ — j/'~W= _ ±j >_=jW ~? j?j±J°EX?Wj%j?Wj? / K_X>±_E

/X~? K ~ ? = /_ ? /= h v? %±_K/XKj* [j ^=jW _ ;_^j oU * mcmhu K /= ik j 1 !~± ~^ ± =/^WXj= ~!

/'j X— % XK_ /X~ ? = ~! - j/'~W vh Xhjhh /'j ;_^j ~> /_X?jW !~± /'j cr k j1 %~X? / _?W _?

_% % ±~ ] X— _/j _;j±_Jj ~! _ /' j ;_^j= ~ > /_ X? j W ~;j± /'j j?j±J° ±_?Jj [j =/^WXjWh

B~± j_K' — j/'~W * [j T F' K~— %_±jW /'j ±jK~?=/±^K /jW j?j±J° ~! % j ? j /±_ /X? J %X~?=

T_/j ='~[ j±X?J %X~?=' [ X/' /' j ±jK~?=/±^K/jW j?j±J° ~ ! ? ~ ? % j ? j /±_ /X? J %X~?= Tj_±°

='~[ j±X?J %X~?=' _?W TE ' % ~ //jW /'j ±_/X~ ~ ! /' j ±jK~?=/±^K /jW j?j±J° [ X/' /'j >j_—

j?j±J° _= _ !^?K/X~? ~ ! /'j > j_— j?j±J°h

chaha CF , j%j?Wj?Kj ~? /'j = /_ ± /X? J %~X?/ ~ ! /'j ='~[j±=

6j = /^ W Xj W /' j X— % XK_ /X~?= ~! /'j ;_±X~^= K_ X> ±_ /X~? — j/'~W= [ X/' j;j?/= K~E

jK/jW X? /' j 0CV k j1 %X~? >j_— h 6j =% X/ /'j=j j;j?/= X? /~ /[~ =_— %j=* >_=jW ~?

/'j = /_ ± / X? J %~ X? / ~ ! /'j ='~[j±=e 4'j % j ? j /±_ /X? J _?W /' j ? ~ ? % j? j /±_ /X? J j;j?/=h

B XJ^ ±j chc ='~[= /'j ±jK~?=/±^K/jW j?j±J° W X= /± X> ^ /X~ ? = !~± /'j=j /[ ~ j;j?/ =_— E

%j=* ~ > /_ X? j W ~? /'j >_=X= ~ ! - j/'~W v* ^=X?J oU f mcmhu K /= ik j1 h 4 ' j — j_? ;_^j=

ub


Ge\") pion runs to find the value of the hadronic section energy scale Bui using this

method. \\·e found an awrage value Bll1 =186.5 counts/Ge\·.

5.2.2 Experimental consequences of each method

The reconstructed energy is defined as

£ E:\[ signal ( . .\DC cts) H..\D signal ( . .\DC cts)

rt~on = --------- + ----------.--l Buuu

( 5.1)

where .--l is the energy scale of the electromagnetic section and But .fl I denotes the

energy scale of the haclronic section according to :\Iethod I.IL or III.

If \1,;e chose :\[cthod I to set the energy scalf' of thl' H..\.D section. we would need

to specify the ern•rgy at which the calibration constant B 1 was determined. since this

rnl11P is energy dependent. Depending on the en1:1rgy. the valuP of B 1 may changP by

as much as 10<;{. The other two methods are based on energy-independent calibra

tion constants. In practicl'. we used a value B1 = 151.--1 cts/Ge\· for our studies of

the implications of :\[ethod I. i.e .. the value obtained for the 56 Ge\· point and an

approximate average of all the values obtained over the energy range we studied.

For each method. we ( 1) comparPd the reconstructed energy of penetrating pions

(late showering pions) with the reconstructed eneq~y of noupenetrating pions (early

showering pions) and (2) p!otted the ratio of the recor?~tructed energy with the beam

energy as a function of the beam energy.

5.2.2.1 Dependence on the starting point of the showers

\\"e studied the implications of the various calibration methods with events col

lected in the 8.6 GeV pion beam. \Ve split these e\·ents into two samples. based on

the starting point of the showers: The penetrating and the nonpenetrating events.

Figure 5.5 shows the reconstructed energy distributions for these two event sam

ples, obtained on the basis of :\fethod I, using B1 = 151...! cts/GeV. The mean values

49

~ ! /'j=j /[~ W X=/± X> ^ /X~ ? = WX!!j± >° mcRh B±~— /'j=j ±j=^/=* [j K~?K^Wj /' _ / ^=X?J

- j/'~W v /~ =j/ /'j j?j±J° =K_j ~! /'j '_W±~?XK =jK/X~? ~! /'j K_ ~ ±X— j/j± X? /±~W^Kj=

_ Wj%j?Wj?Kj ~! /'j ±jK~ ? =/±^ K /jW j?j±J° ~? /'j = /_ ± /X? J %~X?/ ~ ! /' j %X~? ='~[ j±h

4 'X= X=h X? !_K/* _ ~JXK_ _? W X?j;X/_> j K~?=j*^j?Kj ~! ^=X?J /' X= — j/'~W [ X/' _

?~?K~— %j?=_/X?J K_ ~ ±X— j/j±h v! % j? j /±_ /X? J %X~?= _±j ^=jW /~ =j/ /' j j?j±J° =K_j

!~± /'j '_W ±~? XK =jK/X~?* /' j ? X/ X= ~?° !~± /' X= % _ ±/XK^ _ ± =_— %j ~ ! %X~?= /' _ / /'j

j?j±J° [X >j ±jK~?=/±^K/jW K~±±jK/°h 4 'j ;_^j ~ ! oU !~^?W ^=X?J - j/'~W v JX;j=

_ _±Jj± [ jXJ'/ /~ /'j = XJ?_ X? /'j '_W±~? XK =jK/X~?h L X~?= ['XK' >jJ X? ='~[ j±X?J X?

/'j j jK/±~— _J?j/XK =jK/X~? W~ ?~/ !^° >j?j!X/ !±~— /' X= N>~~=/X?JN ~ ! /'j ' _W ±~? XK

=jK/X~? A= =XJ?_ _?W [X /'j±j!~ ±j '_;j _ ±jK~?=/±^K/jW j?j±J° ['XK' X= =— _j± /' _ ?

/' _ / ~! % j? j /±_ /X? J %X~?=h

BXJ^±j chr ='~[= /'j =XJ?_ W X=/±X>^ /X~?= !~± /' j =_— j j;j?/ =_— %j=* >^/ /' X=

/X— j - j/'~W vvv '_= >jj? ^=jW /~ K_ K^ _ /j /'j ±jK~?=/±^K/jW j?j±J° ° o S f mtrhc

K~^? /= ik ~1 'h v? /'X= K_=j* /' j — j_? ;_^j= ~! /'j ±jK~?=/±^K/jW j?j±JXj= ~! /'j %j?jE

/±_ /X? J _?W /' j ? ~ ? % j? j /±_ /X? J %X~?= [j±j !~^?W /~ >j j*^_ [ X/' X? /' j j]%j±X— j? /_

^?Kj±/_ X? /Xj= T_ =— _ !±_K /X~? ~! FR'h

c ha hE ha Z XJ?_ ?~?X?j_±X/°

B~± '_W ±~? ='~[j±=* /' j _;j±_Jj j?j±J° !±_K/X~? K_±±XjW >° N “ = _ ? W ~ /'j± % _ ± / X E

Kj= Wj;j~%X?J jjK /±~— _J?j/XK ='~[j±= TjhJhh 0~=' X?K±j_=j= _= _ !^?K/X~? ~! j?j±J°

Dmnh mu7h 4 ' X= K_^=j= _? <* N0 <*1<5 =XJ?_ ?~? X?j_±X/° !~± '_W±~?= X? q]] ?~?K~— E

%j?=_/X?J K_~±X— j/j±=h 4 ' X= X? /±X?=XK ?~? X?j_±X/° _% % j_±= ['j? /' j %X~? j?j±J° X=

±jK~?=/±^K /jW ^=X?J /'j K _ X> ±_ /X~ ? K~ ? =/_? / o S !~± /' j =XJ?_= !±~— /'j '_W ±~? XK

K_ ~ ±X— j/j± =jK/X~?h v! - j/' ~ W v X= ^=jW /~ ±jK~?=/±^K/ /'j j?j±J° ~ ! %X~?=* /'j? ~?j

=jj= _ ]q04—0 ?~? X?j_±X/° /' _ ? X! - j/'~W vv ~± vvv X= ^=jWh 4'X= K_? >j ^?W j±=/~~W

!±~— /'j !_K/ /' _ / _= /'j j?j±J° ~! /'j %X~? ='~[j± X?K±j_=j=* — ~±j _ ? W — ~±j j?j±J°

X= Wj%~=X/jW X? /'j '_W±~? XK =jK/X~? ~! /' j K_~ ±X— j/j±h v? - j/'~W v* /' j =XJ?_ !±~—

cs


of these two distributions differ by 15'1!:. From these results. we conclude that usmg

:\Icthod I to set the energy scale of the ha<lronic section of the calorimeter introduces

a dependence of the reconstructed energy on the starting point of the pion shower.

This is. in fact, a logical and inevitable consequence of using this method with a

noncompensating calorimeter. If penetrating pions are used to set the energy scale

for the ha<lronic section. then it is only for this particular sample of pions that the

energy will be reconstructed correctly. The value of B1 found using :\letho<l I gives

a larger weight to the signal in the hadronic section. Pious which begin showering in

the electromagnetic section do not fully benefit from this ··boosting .. of the hadronic

section·s signal and will therefore have a reconstructed enPrgy which is smaller than

that of penl'tra.ting pious.

Figure 5.G shows the signal distributions for the same evPnt samples. but this

time :\h!thod III has been used to cakulatl' the reconstructed energy ( Btu = 186 .. j

counts/GP\.). In this case. the mean \·,dues of the reconstructf'd energies of the pene

trating and the nonpenetrating pious were found to be equal within the experimental

uncertainties ( a small fraction of l 7c:).

:- •) •) •) ;J _____ _ Signal nonlinearity

For hadron showers. the average energy fraction carried by ;r0s and other parti

des developing electromagnetic showers ( e.g .. TJS) increases as a function of energy

[13, 1-1]. This causes an intrinsic signal nonlinearity for hadrons in all noncom

pensating calorimeters. This intrinsic nonlinearity appears when the pion energy is

reconstructed using the calibration constant B1u for the signals from the hadronic

calorimeter section. If ).fethod I is used to reconstruct the energy of pions, then one

sees a larger nonlinearity than if :\Iethod II or III is used. This can be understood

from the fact that as the energy of the pion shower increases, more and more energy

is deposited in the hadronic section of the calorimeter. In ~Iethod I, the signal from

50

mas m wEe± hj= Uca♦; -j_? chatr

mss 0-Z a

) x ] 1 ? W ± r c h ♦ a i UUcts aE p GC g ~?=/_? / Uacha ± X hupr

v U Q -j_? ch I~UX ± g hccrrrEg Urs GG L ]

[c+K±E_ a a s p E

Eu“ E

as E

O ff©

ncs E

nss E

acs E

ass E

mcs E

mss E

cs E

ip n ms man mc mphc as

5'nSqksj * •k*k■]c■p*~ •p^*’

Ihc ac

1jj±Y-Z

W Q A aX h E*AjK?

L]EE

pn ms man mc mphc as aan ac

5]x■*FS3ks'C *^*•k*k■]c■p*~ •p^*’

B XJ ^ ±j chce 4'j ±jK~?=/±^K/jW j?j±J° ~! %j?j/±_/X?J T/~%' _?W ?~?%j?j/±_/X?J T>~//~—' %X~^= ['j? - j/'~W v X= ^=jW /~ !X?W /'j ;_^j ~ ! yB

/' j '_W±~?XK =jK/X~? ~! /'j K_ ~ ±X— j/j ± X= N> ~ ~ =/j W N [X/' ±j=%jK / /~ /'j =XJ?_ !±~—

/' j j jK/±~— _J?j/XK =jK/X~? ~ ! /' j K_~ ±X— j/j±h

B XJ^±j chp ='~[= /'j ±_/X~ ~ ! /' j ±jK~ ? =/±^ K /jW j?j±J° _? W /'j Wj%~=X/jW j?j±J°

_ = _ !^?K/X~? ~! /' j _ / /j ± !~± _ /' ±jj W X!!j±j?/ K_ X> ±_ /X~? — j/'~W=h w_K' W _ /_ %~X?/

±j% ±j=j? /= /'j — j_? ;_^j ~! /' j W X= /± X> ^ /X~ ? ~ ! w ±jK~? Tw *^_/X~? chm'h ['j±j _ %X~?=h

% j ? j /±_ /X? J _?W ? ~ ? % j? j /±_ /X? J * '_;j >jj? /_ 9 j ? X? /~ _KK~^?/h w_K' W _ /_ =j/ [_= !X/

[ X/' /'j !^?K/X~?

cm


120 -

100

80

60

20 -

/ '

f -r /

/--

0 - -----==-

350

300

0

250 --

200 -

s

_J

7.5

~~ \

\

J\

\!e:Jn

-\-~:;l.,-;_----, ,

10 12.5 15

E,....1t;eVI - penetrating pions

-, I

/ :. ~~ .. ·es : '.'e,:;r

:!.28'5

~ :s.2 = 3.4 7,j 5.:o~= o.:,soc::-c·

Cl ..J • -

17.5 20 22.5

• 2. :5 .•

:~i::. ::..:.~~::-:· ~ ~ - -~ : ..: .:. . ~ - ' ..

ISO - -~-------

' 100

50 -r ~.

I t...-, ,.r ,,.,__ 0 --=·---'------~---" ..... -;;-,_-

0 2.5 5 7.5 10 12.5 15 17.5 20

E,_.(GeV) - nonpenetr.iting pions

25

25

Figure 5.5: The reconstructed energy of penetrating (top) and nonpenetrating (bottom) pious when Method r is used to find the value uf B,

the ha<lronic section of the calorimeter is ,. boosted" with respect to the signal from

the electromagnetic section of the calorimeter.

figure 5, 7 shows the ratio of the reconstructed energy and the deposited energy

as a function of the latter for all three different calibration methods. Each data point

represents the mean value of the distribution of Erecon (Equation 5.1 ). where all pions,

penetrating and nonpenctrating, have been taken into account. Each data set was fit

with the function

51

mss E

=~ E

rs E

us E

as E

O O

ans E

ass E

mcs E

FOO E

cs E

O #

Y ±]L X??

v 8jK? chprI 08n Uh bhh TF

o '£g1nK?/i cs bnhcc ± 4 ■ mEX

X -jK?

)A 8 Y G

Eo = h

:

r t ms ma

w G G Xk j1 'h %j?j/±_/X?J %X~?=

mu mr mt

©

e 8Z

* . N

4hq G

r t ms ma

5 Y Yp3 ks ' * *^*•k*k■]c■p*~ •p^*’

mu mr mt

B XJ ^ ±j chre 4'j ±jK~?=/±^K/jW j?j±J° ~! %j?j/±_/X?J T/~%' _?W ?~?%j?j/±_/X?J T>~//~— ' %X~?= [ 'j? -j/'~W vvv X= ^=jW /~ !X?W /'j ;_^j ~ ! yB

T y±jK~? '

Y■Wj%~=X/— X E!E —nU vvv YWj%~=X/ Tcha'

4 ' j * ^ _ ? /X/° "l iY X± ['XK' X= _ — j_=^±j ~! /' j =XJ?_ ?~? X?j_±X/° * X= <usR _±Jj±

[ 'j? - j /' ~ W v X= ^=jW _= K~— %_±jW /~ - j/'~W vvvh

ca


100

80

60 --

20

0 0

250

200 -

150

__/

I -,f

~/

____ ........

?

I .J

r

6 8 10 12

E,....1Ge\'1. penetrating pions

100 -r \

' "\ 50 c,_ -/

0 ~_L~ ~--'-=-,

0 ? .. 6 8 10 12

E,.....tGe\'1 · nonpenetrating pions

. - ..... --:;•...,.

6. 76.

16

16

18

18

Figure 5.6: The reconstructed energy of penetrating (top) and nunpenetratiag {bottom) pious when .\[ethod III is used to fin<l the value of B.

(Erecon) £deposit

(- •)) :J __

The quantity k2 / k1 , which is a measure of the signal nonlinearity. is "--10% larger

when :\Iethod I is used as compared to .\Iethod III.

52

9 mhm *Dn

! ±Y ±

v m '> m_=

ueo

OC0

uey

BXJ^±j chpe 4'j ±_/X~ ~! /'j ±jK~?=/±^K/jW j?j±J° _?W /'j Wj%~=X/jW j?j±J° _= _ !^?K/X~? ~! /'j j?j±J° Wj%~=X/jW >° %X~^= ='~[j±X?J X? /'j g,B L^J 8%J±_Wj K_~±X—j/j±h 0j=^/= _±j JX;j? !~± /'j /'±jj K_X>±_/X~? —j/'~W= WX=K^==jW X? /'j /j]/h 4'j K^±;j= /'±~^J' /'j %~X?/= _±j !X/= /~ /'j !^K/X~? X? w*^_/X~? chah

■chahn B X?_ j?j±J° ±jK~?=/±^K/X~?

x= K_? > j =jj? !±~— B XJ^±j chph /' j ;_^j ~! /'j ±jK~ ? =/±^ K /jW j?j±J° W~j= ? ~ /

j*^_ /'j ;_^j ~! /' j Wj%~=X/jW j?j±J° TXhjh* T"1jK~?'iEYWj%~=X/E ±jJ_±Wj== ~! [ 'XK'

— j/'~W X= ^=jW /~ =j/ /' j j?j±J° =K_j= ~ ! /'j '_W±~?XK =jK/X~? h v? ~ ±Wj± /~ _±±X;j _ / /' j

K~±±jK/ ;_^j ~ ! /'j j?j±J° Wj%~=X/jW >° _ %X~? X? /'j K_ ~ ±X— j/j±* ~?j — ^=/ — ^/X% °

/'j ±jK~?=/±^K /jW j?j±J°* !~^?W _KK~±W X?J /~ w *^_/X~? chm* >° _? j?j±J°EWj%j?Wj?/

K~±±jK/X~? !_K /~ ±* ['XK' X= =X— %° /'j X?;j±=j ~ ! /'j K^±;j= ='~[? X? B XJ^±j chph 4 ' j

Wj/_X= ~ ! /' X= % ±~KjW^±j _ ±j JX;j? X? x %%j?W X] yh

cn

■ -=/?~W e © 1jeN~W e . 8j A NKW N

ms msw, j%~=X/ S3ks'


1.1

r I

~

i; 1 '-.. == .. , -

0.9 -

0.8 -

• 1,1e:r:od : • •:e:-::id: • \fe,~ce! ,,

0.7 _, --~-----------"------, 10 10-

E[)rposil ( Ge V)

figure 5.7': The ratio of the reconstructed energ,J and the deposited energy as a function of the energy deposited by pions showering in the CDF Plug upgrade calorimeter. Results are given for the thre1! calibration methods discussed in the text. The curves through the points a.re fits to the fuctiun in Equation 5.2.

5.2.3 Final energy reconstruction

.-\s can be seen from Figure 5.7, the value of the reconstructed energy does not

equal the value of the deposited energy (i.e., (Erecon) / £deposit· regardless of which

method is used to set the energy scales of the hadronic section. In order tu arrive at the

correct \·alue of the energy deposited by a pion in the calorimeter, one must multiply

the reconstructed energy. found according to Equation 5.1, by an energy.dependent

correction factor. which is simply the inverse of the curves shmvn in Figure 5.7. The

details of this procedure are given in .-\ppendix B.

53

chahu g~?=j*^j?Kj= !~± zj /=

4 'j K~?=j*^j?Kj= WX=K^==jW X? /' j %±j;X~^= =jK/X~? _=~ '_;j ±_— X!XK_/X~?= !~± /'j

j?j±J° — j_=^±j— j?/ ~ ! 7j /= h v? ~ ±W j± /~ Wj/j±— X?j /'j j!!jK/= ~ ! /'j /'±jj — j/'~W=

~? /' j ±j=%~?=j ~! /'j K_~ ±X— j/j± /~ 7j /= * [j ^=jW _ - ~?/j g _±~ %±~J±_— %±j;X~^=°

Wj;j~%jW _= _ %_±/ ~! K_~ ±X— j/j± = /^ W Xj = !~± /'j )q g DmcVh v? /' X= _%%±~_K'* _ 7j / X=

/±j _ /j W _= _ K~jK/X~? ~ ! %_±/XKj=* j_K' [X/' ;_±° X?J j?j±J° _ ? W K'_±Jjh 4'j j?j±J°

~! j_K' 7j / %_±/XK j X= =j jK/jW ±_?W~— ° _KK~±WX?J /~ _ !±_J — j? /_ /X~ ? !^?K/X~?

y°C{ m ° q P ] { ° ] * C { q \ C Tchn'

[ 'j±j y° C { X= /'j % ±~>_> XX/° /'_/ _ 7j / !±_J—j?/ [X j?W ^% [ X/' _ !±_K/X~? K ~! /'j

7j / j?j±J°* _?W ~ X= _ %_±_— j/j±h B ±_J— j?/_/X~? !^?K/X~?= — j_=^±jW >° g, B !_;~±

_ ;_^j ~! q f V h ['XK' [j /'j±j!~±j ^=jW X? /'j=j =X— ^_/X~?=h 4 'j K'_±Jj ~! j_K'

!±_J— j?/ [_= K'~=j? ±_?W~— ° =~ /' _ / nnR ~! /'j /X— j X/ [_= _ ? j ^ /±_ %X~? _?W rpR

~! /' j /X— j _ K'_±JjW %X~?h B~± _ 7j / ~ ! j?j±J° " 7 j/ [j ±_?W~— ° %^jW * %_±/XK j=

!±~— /'j !^?K/X~? X? w *^_/X~? chn =^K' /' _ / " 7 j / f [ 'j±j D■ X= /'j j?j±J° ~!

j_K' 7j / !±_J— j?/h B~± j_K' 7j / !±_J— j?/ [X/' j?j±J° "N*h [j ±_? W ~ — ° %^jW _? j±?

_?W '_W =XJ?_h 1 —S _?W 1 >q%B !±~— /'j j— _?W '_W =XJ?_ W X=/± X> ^ /X~ ? = !~± _ /j=/>j_—

±^? ~ ! j jK/±~?= TX! /'j !±_J— j?/ [_= ?j^ /±_ ' ~± % X~?= TX! /'j !±_J— j? / [_= K'_±JjW'

['~=j >j_— j?j±J° [_= K~=j /~ /'j 7j / !±_J— j?/ j?j±J°h B~± X? =/_? Kj * !~± _ ms k j1

? j ^ /±_ 7j / !±_J— j?/* _ =XJ?_ 1—S _?W q>q% [_= %^ jW !±~— /'j j— _?W '_W =jK/X~?

=XJ?_ W X= /± X> ^ /X~ ? = !~± _? 0 kj1 /j= /> j_— ±^? ~ ! jjK/±~?=h 4 ' j 7j / !±_J— j?/ [_=

/'j? _ //± X> ^ /j W _? j— _ ? W '_W =XJ?_ ~ ! f Tmsit'h1 — _? W c ! _dX f Tm s it '=[

±j=%jK/X;j°h B~± _ ms k j1 K'_±JjW !±_J— j?/* /'j =_— j %±~KjW^±j [~^W >j !~~[jW*

>^ / /' j =XJ?_= [~^W >j %^jW !±~— _ %X~? ±^? ±_ /' j ± /'_? _? j jK/±~? ±^?h 4 ' X=

%±~Kj== [_= ±j%j_/jW !~± j_K' ~! /'j * 7 j / !±_J— j?/= /' _ / — _Wj ^% /'j 7j / ~! j?j±J°

cu


5.2.-l Consequences for .Jets

The consequences discussed in the pre,·ious section also have ramifications for the

energy measurement of jets. In order to determine the effects of the three methods

on the response of the calorimeter to jets, we used a ~Ionte Carlo program previously

developed as a part of calorimeter studies for the LHC (15]. In this approach. a jet is

treated as a collection of particles. each with varying energy and charge. The energy

of Pach jet particle is selected randomly according to a fragmeutatiun function

D(::) = (n + 1)(1 - ::) 0/:: (.5.3)

whPrP D(::) is the probability that a jet fragment will end up with a fraction :: of the

jN Pnergy. and o is a parameter. fragmentation functions mt>asurPd by CDF favor

a value of r, =6. which WP thPrPfore used in thesf' simulations. ThP charge of each

fragment was d10s<'n randomly so that 3:Jo/c, of tht> time it was a neutral pion and 67<Jc

of the time a chargPd pion. For a jet of f~nergy £jet we randomly pulled n particles

, from the function in Equation 5.3 such that £jet = z:=::7 £ 1 where £, is thP energy of

each jet fragment. For each jet fragment with energy £" we randomly pulled an em

and had signal. ..,em and shad. from the em and had si~nal distributions for a testhP,Hil

run of electrons (if the fragment was neutral) or pions (if the fragment was charged)

whose beam energy was close to the jet fragment energy. For instance, for a 10 GeV

neutral jet fragment. a signal sem and shad was pulled from the em and had section

signal distributions for an 8 Ge\" testbeam run of electrons. The jet fragment was

then attributed an em and had signal of S7"1 = (10/S)sem and Sfad = (10/S)shad

respectively. For a 10 Ge\" charged fragment, the same procedure would be followed.

but the signals would be pulled from a pion run rather than an electron run. This

process was repeated for each of the n jet fragments that made up the jet of energy

" 7j/h 4 ' j j?j±J° /'j K_ ~ ±X— j/j ± [~^W '_;j ±jK~?=/±^K /jW !~± /'X= 7j/ /' j ? X= =X— %°

B XJ^±j chZ ='~[= /'j K_ ~ ±X— j /j ± A= ±j=%~?=j /~ 7j /= X? /'j j?j±J° ±_?Jj !±~— acEass

kj1 ^=X?J /'j /' ±jj WX!!j±j?/ K_ X> ±_ /X~ ? — j/'~W= _= _ !^?K/X~? ~! /'j 7j / j?j±J°h B~±

j_K' %~ X? /h FOCOOO 7j /= [ j±j J j?j±_ /jW _?W /' j K_ ~ ±X— j/j±♦= ±j=%~?=j /~ j_K' 7j / [_=

K_ K^ _ /jW _= Wj=K±X>jW _>~;jh x= [_= /'j K_=j !~± =X?Jj %X~?=h /'j =~%j ~ ! /' j K^±;j

!~± - j/'~W vvv X= =~— j[ '_/ =— _j± /'_? /'j = ~ % j ~! /'j K^±;j !~± - j/'~W vh 4'X=

X^ = /±_ /j= /' _ / /'j ?~? X?j_±X/° j!!jK/= Wj=K±X>jW X? ZjK/X~? c ha hECE !~± =X?J j %X~?=

% ±~%_J_ /j X? /~ /'j j?j±J° — j_=^ ±j— j? / ~! 7j /= h

chahc g ~?K^=X~?=

6j '_;j K~— %_±jW /' ±jj WX!!j±j?/ — j/'~W= ~! =j //X? J /'j '_W±~?XK =jK/X~? j?j±J°

=K_j ~ ! _ ~?JX/^WX?_° =jJ— j? /jW K_~±X— j/j±h 4 ' j — j±X/= ~ ! /'j=j — j/' ~ W = '_;j

>jj? = /^ W Xj W [ X/' /j=/>j_— W _ /_ !±~— /'j g , B L ^ J 8 %J±_Wj K_~±X— j/j±h v/ /^±?=

~^/ /' _ / ~?j ~! /'j — j/'~W= T/'j = /_ ? W _ ±W — j/' ~ W ^=jW >° g , B ' X? /±~W^Kj= _ ?^— E

>j± ~ ! ^?Wj=X±_> j =XWj j!!jK/=* =^K' _= _? X?K±j_=jW '_W±~?XK =XJ?_ ?~? X?j_±X/° _?W

_ Wj%j?Wj?Kj ~ ! /'j ±jK~?=/±^K /jW j?j±J° ~? /'j = /_ ± /X? J %~ X? / ~! /'j ' _W ±~ ? ='~[E

j±=h 4 'j=j %±~>j— = _±j _ W X±j K / K~?=j*^j?Kj ~ ! /' j ?~?K~— %j?=_/X?J ? _ /^ ±j ~! /'j

K_~ ±X— j/j±=h 4 'j° K_? >j _;~XWjW ['j? _ WX!!j±j?/ K_ X> ±_ /X~? — j/'~W X= ^=jWh

chn g , B g j? /±_ K_ ~ ±X— j/j ± =/^WXj=

4 'j =_— j %±~>j— = j?K~^? /j ±jW [ 'j? K _ X> ±_ /X? J /'j L ^J 8%J±_Wj K_ ~ ±X— j/j±

_±j _=~ % ±j=j? / !~± /'j g j ? /±_ g , B K_~±X— j/j±h 6j '_;j ^=jW 0^? v — X?X— ^—

±j K~? Tchu'

4 'j ;_^j ~ ! } X= mat K /= ik j 1 h _?W /'j ;_^j ~ ! o Wj%j?W= ~? /'j — j/' ~ W ^=jW Tvh

vvh ~ ± vvv'h

~~


Eiet· The energy the calorimeter would have reconstruc.:ted for this jet then is simply

\

n 5em 5had ) £_recun = ~ _i _ + __ 1 _

Jet ~ -1 B · 1=! • I.II.III

(5.-l)

The value of .-1 is 128 cts/Ge\·. and the value of B depends on the method used (I.

IL or III).

f igurP 5.8 shows the t:alorimeter"s response to jets in the energy range from 25-200

Ge\· using the three different t:alibration methods as a function of the jet energy. For

each point. 10.000 jets were generated and tlw calorimeter·s response to each jet was

cakulated as described above .. ..\s was the case for single pious. the slope of the cmve

for :\fethod I II is somewhat smaller than the slope of the t:urve for :\[et hod I. This

illustrates that the nonlinearity effects described in SPl'tiun 3.2.2.2 for single piuns

propagate into thP energy measun•mf•nt of jets.

- •) -,),_,;J Conclusions

\\"e have compared three different methods of setting the hadronic section energy

scale of a longitudinally segmented calorimeter. The merits of these ml'thods have

been studied with testbeam data from the CDF Plug Cpgrade calorimeter. It turns

out that one of the methods ( the standard method used by CDF) introduces a num

ber of undesirable side effects, such as an increased hadronic signal nonlinearity and

a dependence of the reconstructed energy on the starting point of the hadron show

ers. These problems are a direct consequence of the noncompensating nature of the

calorimeters. They can be avoided when a different calibration method is used.

5.3 CDF Central calorimeter studies

The same problems encountered when calibrating the Plug C'pgrade calorimeter

are also present for the Central CDF calorimeter. \\"e have used Run I minimum

■ - j / ± X ~ _ X

shb ’E

shtc ®

OC0 EEEEEEms

B XJ ^ ±j chte 4'j 7j / j?j±J° ±j=%~?=j ~! /'j L ^J 8%J±_Wj g _~±X— j/j± _= !~^?W ^=X?J /'j - ~?/j g_±~ %±~J±_— Wj=K±X>jW X? /'j /j]/h 4 'j =~%j ~! /'j X?j !X//X?J /'j ±j=%~?=j X= _±Jj± ['j? - j/'~W 2 X= ^=jW /'_? ['j? - j/'~W 222 X= ^=jWh

> X_= W _ /_ /~ ±j%±~W^Kj _ /j = /> j _— j?; X±~?— j?/ X? ~ ±Wj± /~ K~ — % _±j /'j j!!jK/= ~!

K _ X> ±_ /X~ ? - j/'~W= v _?W vvv X? /' j g j? /±_ K_~±X— j/j±h

vWj_°* ~?j [~^W ^=j _ Kj_? /j= />j_— ~ ! %X~?= [ X/' [ jEWj!X?jW — ~— j? /_ /~

W j /j ±— X? j /' j '_W±~?XK j?j±J° =K_jh 4 ' j g j? /±_ K_ ~ ±X— j /j ±= [j±j % _KjW X? _

/j = /> j _ — X? mbtc _?W mbbsh >^ / W _ /_ !±~— /'j=j /j=/= _ ±j ?~ ~?Jj± _;_X_> j ~±

±j j;_? /h v? /'j _>=j?Kj ~ ! /j = /> j _— W _ /_ * ~?j — _° ^=j <* 1 <NR W _ /_ h 6j '_;j ^=jW

— X? X— ^— >X_= W _ /_ !±~— 0 ^ ? v /_9j? X? mbbuEbc /~ — _? ^ !_K /^ ±j _ N>j_— £ ~ ! %X~?=

[ X/' [jEWj!X?jW — ~— j?/_ X? ~ ±Wj± /~ = /^ W ° /' j j!!jK/= ~ ! /' j K_ X> ±_ /X~ ? — j /' ~ W X?

/'j g j ? /±_ K_~±X— j/j±h

cr

)k■ 5*k]~D S3ks'


le-----------------------, I \ ~ • Metnod i

I

;i 0.95 ~ .., JI \,let~OC I;

- Me,r.cc :!I , I

~

0.9 :-

0.85 ,....

0.8 ----------~----~-----10

2 10

Jct Energy lGeV)

Figure 5.8: The j1!t energy response of the Plug Upgrade Calorimeter as found using the Monte Carlo program described in the text. The slope of the line fitting the response is larger when .\Iethod I is used than when :.\fethod III is used.

bias data to reproduce a testbeam em·ironment in order to compart=> th" effects of

calibration ~Iethods I and III in the Central calorimeter.

Ideally. one would use a clean testbeam of pious with well-defined momenta to

determine the hadronic energy scale. The Central calorimeters were placed in a

testbearn in 1985 and 1990. but data from these tests are no longer available or

relevant. In the absence of testbeam data, one may use in situ data. We have used

minimum bias data from Run I taken in 199-1-95 to manufacture a ··beam'' of pions

with well-defined momenta in order to study the effects of the calibration method in

the Central calorimeter.

56

chnhm 0 ^? v — X? X— ^— >X_= W_ /_

L _±/XK j= A — ~— j?/_ _±j %±jKX=j° — j_=^±jW >° /'j /±_K9 X?J K'_— >j± X?=XWj /'j

K_~ ±X— j/j±=* _?W ~?j K_? _==^— j /' _ / <bsbK ~ ! /'j /±_K9= =jj? X? — X?X— ^— >X_=

W _ /_ _±j %X~?=h v? ~ ±W j ± /~ =jjK/ _ =_— %j ~! % _ ±/XK j= /' _ / [~^W >j =^ X/_> j !~± ~^ ±

%^±%~=j* [j — _Wj /' j !~~[X?J ±j*^X±j— j?/=h

■ 4 ' j =^— ~! /'j /~ /_ /±_?=;j±=j j?j±J° Y D 0 — ^=/ >j =— _j ± /' _? /'j Kj? /j±

~ ! — _== j?j±J° ~ ! /'j %izK~X=X~?h Q : 1 f mtss kj1h

■ 4 ' j KE%~=X/X~? ~ ! /'j %±X— _±° ;j±/j] — ^=/ >j [ X/'X? us K— ~! C f sh

■ 4 ' j — X==X?J j?j±J°h [/N B — ^=/ >j j== /' _? EO kj1h 4 ' X= j?=^±j= ±j7jK/X~? ~!

j;j? /= X? ['XK' _ K~=—XK ±_° %_==jW /' ±~^J' /'j W j /jK /~ ± _ / /'j =_— j /X— j _=

/' j •• K~X=X~?h

B~± j;j? /= ['XK' %_==jW /'j=j K^ /= * /±_K9= [j±j =jjK/jW ^=X?J = /_? W _ ±W g , B

/±_K9X?J ±~^ /X?j=h 4 0 ( Z w ) _?W 4 0 ( Z) Ah1 4 'j=j ±~^/X?j= ±j*^X±j ' X/= /~ v?U %±j=j?/

X? /[~ _] X_ =^%j±_°j±= _?W ~?j = /j±j~ =^%j±_°j± ~ ! /'j g 4 g h x /~ /_ ~! mphbkshsun

/±_K9= [j±j ±jK~±WjWh w_K' ~! /'j=j /±_K9= [_= j ] /±_% ~ _ /jW /~ /' j K_~±X— j/j±h 6j

K_ /'j /~[ j± /' _ / /'j /±_K9 j] /±_% ~ _ /j= /~ /'j N /_ ±J j /♦♦ /~[j±h

v? ~ ±W j ± /~ K'~~=j ' XJ' *^_X/° /±_K9=* [j _%% XjW /'j !~~[X?J /±_K9 ±j*^X±j— j?/=e

■ vW~ d shc K—*

■ ’± O # Kj'± d c K— h

■ • N 3 shn k j1 iK*

['j±j %V X= /' j X— %_K/ %_ ±_— j/j ± ~ ! /' j /±_K9h KO X= /'j ;_^j ~ ! K~=j=/ _%%±~_K' /~

/'j >j_— _]X=* _?W C_N€ X= /'j K %~=X/X~? ~ ! /'j % ±X— _ ±° ;j±/j]h

6 X/' /'j=j ±j*^ X±j— j?/=* [j K_? >j ±j_=~?_> ° =^ ±j /' _ / /' j ±jK~?=/±^K/jW /±_K9

X?WjjW K~±±j=%~?W= /~ _ K'_±JjW %_±/XK j h x !/j± /' j _>~;j ±j*^ X±j— j?/= [j±j _%%XjW *

cp


5.3.1 Run I minimum bias data

Particles· momenta are precisely measured by the tracking chamber inside the

calorimeters, and one can assume that "'90% of the tracks seen in minimum bias

data are pions. In order to select a sample of particles that would be suitable for our

purpose. we made the following requirements.

• The sum of the total trans\·erse energy L Er must be smaller than the center

of m,L.,s energy of the ppcollision. fa= 1800 Ge\·.

• The .:-position of the primary vertex must be within -W cm of .: = 0.

• The missing energy. l/1• must be l1!ss than :20 Ge\·. This ensur11s rejection of

en'nts in which a cosmic ray passed through tlH~ detector at the same time as

the pp collision.

Fnr e\·ents which pa.ssPd these cut~. tracks were sekcted usmg standard CDF

tracking routines. TRKSEL and TRKSC\". These routines require hits to lw present

in two a.xial superlayers and one stereo superlayer of the CTC .. .\ total of l "i.9GO.O-t:J

tracks were recorded. Each of these tracks w,L'i extrapolated to the calorimeter. \\"e

' call the tower that the track extrapolates to the ··target"' tower.

In order to choose high quality tracks. we applied the following track requirements:

• Idol S 0.5 cm,

• l.:o - .:vt.ri S .j cm,

• Pt > 0.3 Ge\·/c,

where d0 is the impact parameter of the track, .:0 is the value of closest approach to

the beam axis. and Zrt.c is the .: position of the primary vertex.

\Vith these requirements. we can be reasonably sure that the reconstructed track

indeed corresponds to a charged particle . .-\fter the above requirements were applied,

5i

p*ccshacc /±_K9= ±j— _X?jW h 6j _=~ j X— X?_ /jW /±_K9= !~± ['XK' /'j j?j±J° Wj%~=X/jW

X? /'j /_ ±J j / j jK /±~— _J?j/XK /~[j± % ^= /'j j?j±J° X? /' j '_W±~?XK /~[ j± W X±jK/° >jE

'X?W X/ [_= j== /'_? ms - j1h 4'X= K^ / [_= — j_?/ /~ j X— X? _ /j %_±/XKj= ['XK' WXW ?~/

j=K_%j /' j — _J?j/XK !XjW _? W /'j±j!~±j W XW ?~/ Wj%~=X/ /' j X± j?j±J° X? /' j K_~±X— j/j±h

v/ [_= _=~ — j_?/ /~ K^ / %_±/XKj= ['XK' ' X/ X? /'j K±_K9 >j/[ jj? K_ ~ ±X— j/j± /~[j±=h

6j _=~ K^ / /±_K9= !~± [ 'XK' /'j j?j±J° X? /'j /_ ±J j / j jK /±~— _J?j/XK ~± '_W±~?XK

/~[j± [_= J ±j_ /j ± /' _? ubb kj1h

ZX?Kj [j ~?° [ _?/jW /~ =/^W° /' j g j? /±_ K_ ~ ±X— j/j ± T?~/ /' j 6 _ ~± L ^J

K_~±X— j/j±='* [j ±j*^ X±jW /'j /±_K9 /~ ' X/ /'j K_ ~ ±X— j/j ± [ X/'X? /'j j /_ ±_?Jje

Li’ d shrkh v? ~±Wj± /~ !^ ±/' j ± j— ^_/j /'j /j=/>j_— j?; X±~?— j?/* [j =jjK/jW /±_K9=

['XK' [j±j X=~_/jW* Xhjhh %_±/XKj= !~± ['XK' ?~ ~ /' j± /±_K9= j ] /±_% ~ _ /jW /~ /'j au

/~[j±= =^ ±±~^?W X?J /' j /_ ±J j / /~[j±h 6 'j? K'jK9X?J !~± /±_K9= j ] /±_ % ~ _ /jW /~ /'j

=^±±~^?WX?J au /~[j±=* [j WXW ?~/ _%% ° /'j _>~;j K^ /= ~ ± ±j*^X±j— j?/=h BX?_°* [j

=jjK/jW /±_K9= ['XK' ' X/ /'j X??j± t2h ~ ! /'j /_±Jj/ /~[ j± !_Kj _±j_ h v/ '_= >jj?

='~[? /' _ / /'j±j X= X//j _ /j ±_ j_9_Jj ~^ /=XWj /'j /_ ±J j / /~[j± X! /' j /±_K9 'X/= /'j

/~[j± X? /'j X??j± nrbK ~ ! /' j /~[j± !_Kj _ ±j _ DmrVh

v? =^— — _±° * [j _%% XjW /'j !~~[X?J ±j*^X±j— j?/= /~ /±_K9=e

■ ’W~’ d shc K—*

■ ’Y~ < C _ N€ Q d c K— h

■ • N 3 shn k j2 iK *

h S g 4 A l shsm kj1h

“ 6 G F ” 3ksC

■ ±j*^X±j /±_K9 /~ ' X/ K_ ~ ±X— j/j± X? j /_ ±_?Jj* ’±i’ d O hV V *

■ ±j*^X±j ?~ ~ /'j± /±_ K 9 /~ 'X/ K_ ~ ±X— j/j± X? au /~[ j±= =^ ±±~^?W X?J /_ ±J j / /~[j±*

ct


7,550.255 tracks remained. \Ve also eliminated tracks for vvhich the energy deposited

in the target electromagnetic tower plus the energy in the hadronic tower directly be

hind it was less than 10 ~le\·. This cut was meant to eliminate particles which did not

escape the magnetic field and therefore did not deposit their energy in the calorimeter.

It was also meant to cut particles which hit in the crack between calorimeter towers.

\Ve also cut tracks for which the energy in the target electromagnetic or hadronic

tower was greater than --199 Ge\".

Since we only wanted to study the Central calorimeter (not the \Va.JI or Plug

calorimeters). we required the track to hit the calorimeter within the eta range:

i ,,J :S 0.66. In order to furtl11~r em11lat0 the rest beam environmPnt. we selected tracks

which werl' isolated. i.e .. particles for which no other tracks extrapolatt1d to tlw 2--l

tnwers surrounding thP target tower. \\'hen checking for tracks extrapolatt•d to the

surrounding 2--l towers. WP did not apply the above cuts or requirenwnts. Finally. we

selected tracks which hit thP inner 36l7c_ of the target tower face area. It has ben1

shown that there is little lateral lea.kagt! outside the targPC tower if thP track hits the

tower in the inner 36¼ of the tower face area [16].

In summary. we applied the following requirements to tracks:

• /do/ :S 0.5 cm,

• l=o - .:rt.:r! :S 5 cm,

• Pt ~ 0.:3 Ge\"jc,

• £target + £target > O O l Ge\· em had · '

£ target --1gg G \" • em.had < . . e .•

• require track to hit calorimeter in eta range, 1'71 ~ 0.66.

• require no other track to hit calorimeter in 2--l towers surrounding target tower,

58

■ ±j*^ X±j /±_K9 /~ ' X/ X??j± nrR ~! /~[j± !_Kj _±j_h

6 X/' _ ~ ! /'j _>~;j K^ /= _? W ±j*^X±j— j?/=* [j [j±j j!/ [ X/' usbhrnu NJ~Wj?N

/±_K9=h 6j Wj!X?j /'j j?j±J° — j_=^±jW >° /'j K_ ~ ±X— j/j ± _=

b b

D0q] Y [ Yk]*R Y Y D>q%R " &‘$ &‘'p9> ■9>

['j±j w j±±XX X= /'j j?j±J° X? /' j X/' jjK/~— _J?j/XK K _ ~ ±X— j /j ± /~[j± _? W " '_TX X=

/'j j?j±J° X? /'j X /' '_W±~?XK K_~±X— j/j± /~[j±h 4 'j =^ — X= ~;j± /'j b /~[ j± J±XW

Kj?/j±jW ~? /' j /_ ±J j / /~[j±h B XJ^±j chb ='~[= /'j * ^ _ ? /X /° T D 5qU\ • { _= _ !^?K/X~? ~!

/'j — ~— j?/^— • !~± ~^± J~Wj? /±_K9 =_— %jh

OCV E

shu ± I

OCE ±* N

X _O I © © © © o# E # EEEEEEEEEEEEEEEEEE E# z

m a n u c r p

•S3kay'

B XJ^±j chbe 0 _/X~ ~! /'j %_±/XKj j?j±J° ±jK~?=/±^K/jW >° /'j K_~±X—j/j±h D 5qQ ■ _?W /'j %_±/XKj — ~— j?/^— —j_=^±jW [X/' /'j /±_K9X?J =°=/j—* • _= _ !^?K/X~? ~! • !~± X=~_/jW /±_K9= 'X//X?J /'j gj?/±_ K_~±X—j/j± X? /'j X??j± nrR ~! /'j /_±Jj/ /~[j± !_Kjh Zjj /j]/ !~± Wj/_X=h

cb


• require track to hit inner 36% of tO\ver face area.

\Vith all of the abow cuts and requirements, we were left with -109,63--1 ··golden··

tracks. \Ve define the energy me;u;ured by the calorimeter as

9 9

Ecal = L Er!m, + L £had, ( ,5.5) 1=! 1=!

where Eem, is the energy in the ith electomagnetic calorimeter tower and Ehad, is

the energy in the ith hadronic calorimeter tower. The sum is over the 9 tower grid

centered on the target tower. Figure :j_!) shows the quantity ( Ecut/ p) as a function of

the momentum p for our goldPn track sample.

C: \.. --... 1.4 :s " '·' -- 1.2

~

l ~

-+-r -+- -+-

0.8 ,--+--+--+---+---+--e-..... -+---+---+--+--+--+-----..... I

" ~ 0.6 ~

[

0.4 r

0.2 l,

[ 0 '-~-------'----'-_..___ _______ ~------'--~-------~-~

l 2 J 5 6 7

p(GeV/cJ

Figure 5.9: Ratio of the particle energy reconstructed by the calorimeter. Ecal, and the particle momentum measured with the tracking system. p as a function of p for it;olate<l tracks hitting the Central calorimeter in the inner 36% of the target tower face. See text for details.

59

chnh&a y _K9J±~^?W K~ ±±jK /X~ ?

DEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEmhu '

mha Z]

> F •k*k■]c■p*~ •c]■py>k’

OC0 E

XE

OCV _±>»

“Eu ±OCE =

~ #m a n u c r p

•S3ks'Ly'

BXJ^±j chmse 4'j *^_? /X/° bit ■ D*—RN"q] \ •{ %~//jW ;= /'j —~—j?/^—h D *—RN0q< X= /'j h /~/_ j?j±J° X? /'j 0 jjK/±~— _J?j/XK /~[j±= =^±±~^?WX?J /'j /_±Jj/ /~[j± !~± /±_K9= ['XK'

%j?j/±_/j /'j jjK/±~— _J?j/XK =jK/X~? [ X/'~^/ X?/j±_K/X?Jh 4'X= *^_?/X/° X= _? j=/X—_/j !~± /'j _;j±_Jj j?j±J° Wj%~=X/jW X? /'j K_~±X— j/j± >° ?j^/±_ %_±/XKj= _KK~—%_?°X?J K'_±JjW %_±/XKj= /' _ / %±~W^Kj J~Wj? /±_K9=h

y° ^=X?J /'j X=~ _ /X~? ±j*^X±j— j?/ _= Wj=K±X>jW _>~;j* ~?j '~%j= /~ K'~~=j ~?°

%_±/XKj= [ 'XK' _±j ?~ / _KK~— %_? XjW >° ~ /' j ± %_±/XKj= ' X// X? J /'j /_ ±J j / /~[j± ~±

/'j au K_ ~ ±X— j/j± /~[ j±= =^ ±±~^?W X?J /' j /_ ±J j / /~[j±h 6 X/' /'j /±_K9 X? J =°=/j— *

'~[j;j±* X/ X= ~?° % ~==X> j /~ XWj?/X!° K'_±JjW %_±/XKj=h v! _ ?j^ /±_ % _ ±/XK j [j±j /~

_KK~— %_?° /' j %_±/XKj % ±~ W ^ K X? J /'j J~Wj? /±_K9 T_= X? /' j K_=j ~ ! _ •H WjK_°X?J /~

_ K'_±JjW % X~? _?W _ ? j ^ /±_ %X~?' _?W ' X/ /' j =_— j K_ ~ ±X— j/j ± /~[j± _= /'j K'_±JjW

%_±/XKj * /' j ±j [~^W >j ? ~ =XJ? ~ ! /'j _KK~— %_?°X?J %_ ±/XK j X? /'j /±_K9 X? J =°=/j— *

> ^ / /'j j?j±J° — j_=^±jW >° /'j K_ ~ ±X— j/j± [~^W >j _±Jj± /' _? /' _ / %±~W^KjW >°

rs


5.3.2 Background correction

2:: 3' 1.-& I

* r - ~

~ 1.2 ,. r .:: = ~

penetrating particles ,_, - l

0.8 --~

0.6 t i=+-

OA '-

;

' 0.2 ..... .......... ..... ---.......... _... . . . ... ---------..... ------

0 I 2 3 5 6 7

p(GeV)/c)

Figure 5.10: The quantity <J/8 · (Eneutrat!P) is plotted vs the momentum. Eneutral is the , total energy in the 8 electromagnetic towers surrounding the target tower for tracks which

penetrate the electromagnetic section without interacting. This quantity is an estimate for the average energy deposited in the calorimeter by neutral particles accompanying charged particles that produce golden tracks.

By using the isolation requirement as described above, one hopes to choose only

particles which are not accompanied by other particles hitting the target tower or

the 2-l calorimeter towers surrounding the target tower. \\"ith the tracking system,

however, it is only possible to identify charged particles. If a neutral particle were to

accompany the particle producing the golden track (as in the case of a p= decaying to

a charged pion and a neutral pion) and hit the same calorimeter tower as the charged

particle, there would be no sign of the accompanying particle in the tracking system.

but the energy measured by the calorimeter would be larger than that produced by

60

/' j K'_±JjW % _ ±/XK j _~?jh v? ~ ±W j± /~ ±j% ±~ W ^ Kj /'j /j= /> j_ X? j?;X±~?— j?/* /' X=

? j ^ /±_ >_K9J±~^?W — ^=/ >j _KK~^?/jW !~±h

6 j j=/X— _/jW /' X= >_K9J±~^?W X? /'j !~~[ X?J [_°h Q ^ / ~! /'j /±_K9= ±j— _X? X?J

_ ! /j ± _%%° X?J _ ~! /'j K^/= _ ? W ±j*^ X±j— j? /= Wj=K±X>jW _>~;j* [j =jjK/jW /±_K9=

[ 'XK' Wj%~=X/jW j?j±J° X9j _ — X% %_±/XKj X? /' j j jK /±~— _J?j/XK =jK/X~?* Xhjhh /' j°

% j ? j /±_ /j W /'j j— =jK/X~? [ X/' ~ ^ / ^?Wj±J~X?J _ ?^Kj_± X? /j±_K/X~? h B±~— /'j=j

% _ ±/XK j = * /'j±j X= ?~ _/j±_ j_9_Jj X?/~ /' j =^ ±±~ ^ ? W X? J jjK/±~— _J?j/XK /~[ j±=h

4 ' j j?j±J° X? /' j 0 =^ ±±~^?WX?J j jK /~— _J?j/XK /~[j±= /'j? — ^=/ >j _ ±j=^ / ~!

_KK~— %_?° X?J ? j ^ /±_ %_±/XKj=h 6j ^=jW /' X= j?j±J° /~ j = /X— _ /j /'j _;j±_Jj j?j±J°

W j % ~ = X/j W X? j_K' jjK/±~— _J?j/XK K_ ~ ±X— j/j± /~[ j± !~± _ ~ ! ~^ ± J~Wj? /±_K9=h

6j =jjK/jW %_±/XK j= /'_/ Wj%~=X/jW j?j±J° X? /'j j jK/±~— _J?j/XK =jK/X~? X9j _

— X% _= !~~[= T=jj BXJ^±j chma'h 6j Wj!X?jW _ — X%EX9j /±_K9 _= ~?j X? ['XK' /'j

j?j±J° X? /'j /_ ±J j / j jK/±~— _J?j/XK /~[j± [_= >j/[ jj? sha _?W shc kj1 _?W /'j

j?j±J° X? /'j b '_W ±~? XK /~[j±= >j' X?W /'j /_ ±J j / j jK /±~— _J?j/XK /~[j± [_= J ±j _ /j ±

/' _ ? )hQ kj2h 6j K_ /'j=j %_±/XK j= N% j? j /±_ /X? J N %_±/XKj= =X?Kj /'j° % j? j /±_ /j /'j

j jK /±~— _J?j/XK =jK/X~? [ X/'~^/ = /±~ ? J ° X? /j ±_K /X? J h

B XJ ^ ±j chms ='~[ =* !~± % j ? j /±_ /X? J %_±/XK j=* /'j — j_? j?j±J° X? /'j 0 /~[ j±=

=^ ±±~ ^ ? W X? J /'j /_ ±J j / /~[j± — ^/X% XjW >° b it T=X?Kj ~ ^ ± j?j±J° Wj!X?X/X~? X?K^Wj=

_ b j jK /±~— _J?j /XK /~[j± =^—' _ ? W WX;XWjW >° /' j — ~— j?/^— ~! /'j J~Wj? /±_K9 *

_= _ !^?K/X~? ~! /' X= — ~— j?/^— h v? ~ /' j ± [ ~±W=* [j '_;j % ~ //jW /'j *^_? /X/°

[ 'j±j D —SN X= /' j j?j±J° X? /'j X/X j jK /±~ — _J ? j /XK K_ ~ ±X— j/j ± /~[j± _?W /'j =^— X=

~;j± /' j 0 j jK/±~— _J?j/XK /~[j±= =^ ±±~^?W X?J /' j /_ ±J j / /~[j±h

Z X?Kj [j [~^W X9j /~ — j_=^±j /' j j?j±J° W j% ~ =X/jW X? /' j K_~±X— j/j± >° £*]6

/' j J~ Wj? K'_±JjW /±_K9* [j = ^ > /±_ K / D *—RN0q< !±~— D 5q< ?~ / ~?° !~± % j ? j /±_ /X? J

% _ ±/XK j = >^ / !~± q]] %_±/XKj= X? ~ ^ ± J~Wj? /±_K9 =_— %j h 6j Wj!X?j /' X= * ^ _? /X/° _=

g D —S■ ' b it \ • D * — R N 0 q ] \ k e Tchr'

rm


the charged particle alone. In order to reproduce the testbeam en\"ironment, this

neutral background must be accounted for.

\\"e estimated this background in the following way. Out of the tracks remaining

after applying all of the cuts and requirements described abo\"e. we selected tracks

which deposited energy like a mip particle in the electromagnetic section. i.e .. they

penetrated the em section without undergoing a nuclear interaction. From these

particles. there is no lateral leakage into the surrounding electromagnetic cowers.

The energy in the S surrounding Plectomagnetic towers then must be a result of

acl'.ompanying neutral partides. \\·e used this energy to estimatP thP average energy

deposited in each l'!el'.tromagnetic calorimeter tower fur all of our golden tracks.

\\.t> selected partic!Ps that dPposited energy in thP Plectromagnetil'. Sl'ction likl' a

mip as follows (seP Figure 0.12). \\"p ddined a mip-likP track as one in which the

energy in the target electromagnetic tower was lwtwt'en 0.2 and 0.5 Ge\· and the

energy in the !) hadronic towt>rs behind the target eil'l'.tromagnetic tower was greater

than LO GP\·. \\"e call these particles ·'penetratini( particles since they penetrate the

electromagnetic section without strongly interacting.

figure 5.10 shows, for penetrating particles. the mean energy m the 8 tow1·rs

surrounding the target tower multiplied by 9/8 (since our energy definition includes

a 9 elec·tronrn.gnetic tower sum) and divided by the momentum of the golden track.

as a function of this momentum. In other words, we have plotted the quantity

(£.,.,..,/p) ~ ( [t £,,., • 9/8] /p) (.5.6)

where Eerr,, is the energy in the ith electromagnetic calorimeter tower and the sum is

over the 8 electromagnetic towers surrounding the target tower.

Since we would like to mea~mre the energy deposited in the calorimeter by only

the golden charged track. we subtract Eneutral from Ecal not only for penetrating

particles but for all particles in our golden track sample. \\"e define this quantity as

61

■,k y^]]ky■kJ k*k]~DC kb„;;o

D*5£00 # k*5q] D *—RN0q]*

D5£00\• X= ='~[? _= _ !^?K/X~? ~ ! • X? B XJ^±j chmmh B~± — ~— j?/_ _±Jj± /'_? F k j1 AiKh

/' X= ±_ /X~ _— ~^? /= /~ < sht _— ~=/ X?Wj%j?Wj? / ~ ! j?j±J°h P ~/j /' _ / /'X= K~±±jK /X~?

!~± j?j±J° K_±±XjW >° ?j^/±_ %_±/XK j= _KK~— %_?° X?J ~^± J~W /±_K9= '_= j X— X?_ /jW

/'j j?j±J° Wj%j?Wj?Kj ~>=j±;jW >j!~±j /' X= K~ ±±jK /X~ ? [_= _%% XjW TB XJ^±j chb'h

mhu

mha E

F E

O C0 e0*

OCV %UE

shu 00

OCE

r p

•S3ks'Ly

B XJ^ ±j chmme TD 5£00\ • ' ;= • !~± X=~_/jW /±_K9= ' X//X?J /'j gj?/±_ K_~±X— j/j± X? /'j X??j±& E O O ' $ ± Y GGGGGGG Y h GGGGGGGGG ± GGGG ±U ■ X X ±E+ * ? h ± X h E XnrR ~! /'j /_±Jj/ /~[j± !_Kjh D■5£00 X= Wj!X?jW _= D K_i # D *—RN0qUB Zjj /j]/ !~± Wj/_X=h

ra


the corrected energy. Ecorr:

Ecorr = Ecal - Eneutral· (5.'i)

Ecorr!P is shown as a function of pin Figure -5.11. For momenta larger than l Ge\'/c.

this ratio amounts to ....., 0.8 almost independent of energy. \"ote that this correction

for Pnergy carried by neutral particles accompanying our gold tracks has eliminated

the energy dependence observed before this correction wa.s applied (Figure 5.9).

-~ 1.4 ... = :..

~

---- 1.2

I

0.8

0.6

0.4

0.2

0

r r I r \.. L

I 2 3 4 5 6 7

p(GeV)/c

Figure 5.11: (Ecorr/P) vs p for isolated tracks hitting the Central calorimeter in the inner 36% of the target tower face. Ecorr is define<l as Ecal - Eneutrul· See text for details.

62

chnhn g ~— %_±X=~? ~ ! K_ X> ±_ /X~ ? — j /' ~ W =

6 j [X ?~[ WX=K^== /'j K~?=j*^j?Kj= ~ ! K_ X> ±_ /X~ ? — j/'~W= v _ ? W vvv X? /±~W^KjW

X? ZjK/X~? cha ['j? _% % XjW /~ /'j g , B g j?/±_ K_ ~ ±X— j/j ±h

chnhnhm - j/'~W v

ps ±

!6 c;

cs wE

us wE

cs ±

j?X j?j±J°* m /~[j±

'^W j?j±J°* b /~[j±=

BXJ^±j chmae 4'j j?j±J° X? /'j /_±Jj/ /~[j± ~! /'j jjK/±~— _J?j/XK =jK/X~? T/~%' _?W /'j j?j±J° X? /'j b '_W±~?XK /~[j±= >j'X?W /' j /_±Jj/ /~[j± T>~ //~— 'h Z'~[? _±j %_±/XKj= [X/' —~—j?/_ >j/[jj? c _?W mc kj1iKh L j?j/±_ /X?J %_±/XKj= _ ±j Wj!X?jW _= /'~=j !~± ['XK' /'j j?j±J° X? /'j /_±Jj/ jjK/±~— _J?j/XK /~[j± X= >j/[jj? shaEshc kj1 _?W /'j j?j±J° X? /'j b '_W±~?XK /~[j±= X= J ±j_/j± /'_? mhs kj1h P~?%j?j/±_/X?J %_±/XKj= _±j /'~=j !~± ['XK' /'j j?j±J° X? /'j /_±Jj/ jjK/±~— _J?j/XK /~[j± X= J±j_/j± /'_? shp kj1h

B XJ^ ±j chma ='~[= /' j j?j±J° X? /' j /_ ±J j / /~[ j± ~ ! /' j j jK/±~— _J?j/XK =jK/X~?

_?W /'j j?j±J° X? /' j b '_W±~? XK /~[ j±= >j' X?W /'j /_ ±J j / j jK /±~— _J?j/XK /~[j± !~±

rn


5.3.3 Comparison of calibration methods

\\'e will now discuss the consequences of calibration methods I and III introduced

in Section 5.2 when applied to the CDF Central calorimeter.

5.3.3.1 :-.Iethod I

70

60

50

-10

JO

20

10

0 0

~ """'" - ---- "-..:· --'--1 ,... .... ""-~ .... '""'J.~,

2 -I 6 ll

em energ_v, I tower

·-------- --------------- - --------·-·------l! -

-ll)

!" r ~\'S 8 - i 7

- I ~

2 -

0

6 ,..: • r - ;l r' ..;L_j.-1 .. : i

~~;-1,- -I 7

1

-,i -,"~ -,r. ~-~ ~ c; -q177- r . ;: ~ ... ,. -.ci,:-- ~

n .,

0 6 ll

had energy, 9 towers

r

I•

lO

10

Figure 5.12: The energy in the target tower of the electromagnetic section (top) and the energy in the 9 hadronic towers behind the target tower (bottom). Shown are particles with momenta between 5 and 15 GeV/c. Penetrating particles are defined as those for which the energy in the target electromagnetic tower is between 0.2-0.5 GeV and the energy in the 9 hadronic towers is greater than 1.0 GeV. ~onpenetrating particles are those for which the energy in the target electromagnetic tower is greater than O. i GeV.

Figure 5.12 shows the energy in the target tower of the electromagnetic section

and the energy in the 9 hadronic towers behind the target electromagnetic tower for

63

%_±/XK j= [ X/' c d • d mc k j1 iK h Q ? /'j >_=X= ~! /'j=j %~/=* [j WX;XWjW /'j =_— %j

~ ! %_±/XK j= X? /~ N% j? j /±_ /X? J N _?W N?~?%j?j/±_ /X?JN %_±/XKj=h

6j Wj!X?jW N% j?j /±_ /X?JN %_±/XKj= _= Wj=K±X>jW X? ZjK/X~? chnhah ?_— j° %_±/XK j=

!~± ['XK' /' j j?j±J° X? /' j /_±Jj/ j jK /±~— _J?j/XK /~[ j±* X= >j/[jj? OCE _?W

shc kj1A _? W /'j j?j±J° X? /' j b '_W±~?XK /~[j±= > j' X?W /'j /_ ±J j / jjK/±~— _J?j/XK

/~[ j±h D>q%■ X= J ±j_ /j ± /' _? mhs kj1Ah B XJ^±j chma ='~[= /'j W X= /± X> ^ /X~ ? ~! j?j±J°

X? /' j /_ ±J j / j jK /±~— _J?j/XK /~[j± _?W X? /'j b '_W ±~? XK /~[j±= >j'X?W /'j /_ ±J j /

j jK /±~ — _J ? j /XK /~[j±h 5 ~?%j?j/±_ /X?J %_±/XKj= _±j Wj!X?jW _= % _±/XK j= ['XK' W~ ?~/

% j ? j /±_ /j /'j j jK /±~— _J?j/XK =jK/X~? [ X/'~^ / X? /j ±_K /X? J h 4 'j° >jJX? ='~[j±X?J X?

/'j j jK /±~— _J?j/XK =jK/X~?h v! _ %_±/XKj Wj%~=X/jW — ~±j /'_? shp k j1 X? /'j /_ ±J j /

j jK /±~— _J?j/XK /~[j±* /' j? [j K_jW X/ _ ? ~ ? % j ? j /±_ /X? J %_±/XKj h

B XJ^±j chmn ='~[= W X=/±X> ^ /X~ ? = ~! /'j * ^ _? /X/° D 5£00\ • ;= • !~± %j?j /±_/X?J _?W

? ~ ? % j ? j /±_ /X? J %X~?= =j%_±_/j° h D5£00\ • X= < m a &4 _±Jj± !~± % j ? j /±_ /X? J %X~?= /' _ ?

!~± /'j ? ~ ? % j ? j /±_ /X? J ~?j=h 4'X= X= W^j /~ /'j !_K/ /' _ / /'j j?j±J° =K_j ~! /'j

'_W±~? XK =jK/X~? ~ ! /'j g j? /±_ K_~ ±X— j/j± [_= Wj /j ±— X?jW ^=X?J - j/'~W vh L X~?=

±jJ X=/j± _ =— _j ± =XJ?_ X? _ ?~?K~— %j?=_/X?J K_ ~ ±X— j /j ± /' _? j jK/±~?= ~! /'j =_— j

j?j±J°h ZX?Kj %X~?= [j±j ^=jW /~ K_ X> ±_ /j /'j '_W ±~? XK =jK/X~? > ^ / *£N /'j j jK/±~ E

— _J?j/XK =jK/X~? * /'j =XJ?_ /' _ / ?~? % j? j /±_ /X? J %X~?= j_;j X? /' j jjK/±~— _J?j/XK

=jK/X~? X= ?~ / =^!!XKXj?/_° >~~=/jWh 4 '^= /'j ±jK~?=/±^K /jW j?j±J° ~ ! ?~?% j? j /±_ /X? J

%X~?= X=* ~? _;j±_Jj* /~~ =— _h v/ X= X— % ~ ±/_? / /~ ? ~ /j /' _ / S £1N '_W±~?= ' X// X? J

/'j K_ ~ ±X— j /j ± ^<]] X? /j ±_K / X? /'j j jK /±~— _J?j/XK =jK/X~? h - ~=/ '_W±~?= W~ ?~/

— X±_K^ ~^=° 9?~[ /~ [ _X/ ^ ? /X /'j° ' X/ /'j '_W±~? XK =jK/X~? ~ ! /' j K_~±X— j/j± /~

>jJX? Wj% ~ =X/X? J =XJ?X!XK_?/ _— ~^?/= ~ ! /' j X± j?j±J°h

v/ ='~^W _=~ >j ?~/jW !±~— BXJ^±j chmn /' _ / /'j ;_^j ~! D \ • !~± % j? j /±_ /X? J

%X~?= X= ?~ / F h 4 'j j?j±J° =K_j ~! /'j '_W±~?XK =jK/X~? ~! /'j g j? /±_ K_~±X— j/j±

[_= W j /j ±— X? jW [ X/' cphm kj1A % j? j /±_ /X? J %X~?= DmrVh B~± /'j=j cphm kj1 %X~?=* D \ •

[_= Wj!X?jW /~ >j mh B~± ~[j± j?j±J° %X~?= [X/' — ~ — j? /_ >j/[ jj? c _?W ms kj1♦iK h

ru


particles with 5 < p < 15 Ge\"/c. On the basis of these plots. we divided the sample

of particles into .. penetrating'· and "nonpenetrating·· particles.

\Ye defined ··penetrating'' particles as described in Section 5.3.2, namely particles

for which the energy in the target electromagnetic tower. E!'::;9et is between 0.2 and

0.5 GeV and the energy in the 9 hadronic towers behind the target electromagnetic

tower. L~=i Ehad, is greater than 1.0 Ge\·. Figure 5.12 shows the distribution of energy

in the target electromagnetic tower and in the 9 hadronic towers behind the target

electromagnetic town. ~onpenetrating particles are defined as particles which do not

penetrate the electromagnetic section without interacting. They begin showering in

the electromagnetic section. If a particl,, deposited more than 0., GP\. in the target

electromagnetic tower. then we called it a nonpenetrating partic!P.

Figun• 5.13 shows distributions of thP quantity EcorrlP rs p for (Will'trating and

nonpe1wtrating pions s1~pa.rately. Ecarr/ p is -l2'X larger for penetrating piuns than

for the nonpenetrating ones. This is due to tht> fact that the enPrgy scale of tlw

hadronic section of the Central calorimetPr was determim•d using .\Iethud I. Pious

regiswr a smaller signal in a noncompensating calorimeter than elPctrons of the same

energy. Since pions were used to calibrate the ha<lronic section but not the electro

magnetic section, the signal that nonpenetrating pions leave in the electromagnetic

section is not sufficientaly boosted. Thus the reconstructed energy of nonpenetrating

pions is. on average, too small. It is important to note that most hadrons hitting

the calorimeter will interact in the electromagnetic section. 1Iost hadrons do not

miraculously know to wait until they hit the hadronic section of the calorimeter to

begin depositing significant amounts of their energy.

It should also be noted from Figure 5.13 that the value of E / p for penetrating

pions is not 1. The energy scale of the hadronic section of the Central calorimeter

was determined with 5i.l GeY penetrating pions (16]. For these 57.1 GeV pions, E/p

was defined to be 1. For lower energy pious with momenta between 5 and 10 GeV/c.

6-l

/' j ;_^j ~! D \ • X= =— _j± /' _ ? Fh 4 ' X= X?WXK_/j= _ ?~? X?j_±X/° ~ ! /' j K_~±X— j/j±A=

±j=%~?=j ['XK' X= W^j /~ /' j ?~?K~— %j?=_/X?J ? _ /^ ±j ~ ! /'j '_W ±~ ? XK =jK/X~? ~!

/' j K_ ~ ±X— j/j±h 4 'j =_— j j!!jK/ [_= ~>=j±;jW X? /'j L ^J 8 %J±_Wj g _~±X— j/j±

T=jj B XJ^±j c hp 'h4 'j — _J ? X/^ W j ~! /'j ?~? X?j_±X/° ~ ! /' j '_W ±~? XK =jK/X~? ~! /'j

g j ? /±_ K_ ~ ±X— j/j ± X= X? _J±jj— j?/ [ X/' [ '_/ [j [~^W j]%jK/ >_=jW ~? /'j — _/j±X_

K~— %~=X/X~? ~ ! /'j Wj;XKj DmpVh

ma

ms

0

V

u%j?j/±_/X?J* cd%dmc

asmphc

mcmaEc

msphc

cac

O E_?h

I b—q0 ■d-ZGGGGGGGGGGGGGkha p U j

?~?%j?j/±_/X?J* cd%d mc

w i %K ~ ±±

B XJ^ ±j chmne D5£00\• !~± %j?j/±_/X?J _?W ?~?%j^j/±_/X?J %X~?= ['j? - j/'~W v X= ^=jWh Z'~[? _±j %_±/XKj= [X/' — ~— j?/_ >j/[jj? c _?W mc kj1iKh 4'j —j_?= ~! /'j WX=/±X>^/X~?= WX!!j± >° <maR h P~/j /'_/ —~=/ /±_K9= _±j X? /'j ?~?%j?j/±_/X?J K_/jJ~±°h

rc


the value of E/p is smaller than 1. This indicates a nonlinearity of the calorimeter·s

response which is due to the noncompensating nature of the hadronic section of

the calorimeter. The same effect was observed iu the Plug Cpgrade Calorimeter

(see Figure 5.7).The magnitude of the nonlinearity of the hadronic section of the

Central calorimeter is in agreement with what we would expect based on the material

composition of the device [l i].

-I.?

-10 -II :.

-! I ,7 i

0 • ___ -~------..... -- ---L~- L_ -- .

22.5 !O -

17.5 _ 15 .

l.?.5 10 --

1.S

5 !.5

-

0

r: ,j

- '

!

i

-------------

penetrJtin11:, 5<p<l5

J 5

:;MS

nonpenetrJting, S<p< 15

L..7 ~ o· ~ ~~--....-~~~_.,..._,.............,' '-'---'---'""'"'-_.._~.:.......-..... ~~_.._-~~-

0 J s

Figure .j_ 13: Ecorr/P for penetrating and nonpenetrating pions when ;\letho<l I is used. Shown are particles with momenta between 5 and 15 GeV /c. The means of the distributions differ by ..... 12%. ~ote that most tracks arc in the nonpenetrating category.

6.j

eCGC1 nk■,^J 222

v? ~ ±W j± /~ j=/_> X=' - j/'~W vvv X? /'j g j? /±_ K_~ ±X— j/j±* [j ?jjW /~ W j /j ±— X? j

_ — ^ /X% XK_ /X;j !_K /~ ±* v /' _ / —^=/ >j _%% XjW /~ /' j =XJ?_= !±~— /'j '_W ±~ ? XK

=jK/X~? X? ~ ±Wj± j*^_X\j D 0q< \ • !~± % j ? j /±_ /X? J _? W ? ~ ? % j? j /±_ /X? J %X~?=h 6j '_;j

Wj /j ±— X?jW /' X= !_K/~±* _ ? W X/ X= ='~[? X? B XJ^±j chmu _= _ !^?K/X~? ~ ! • ~ ! /'j J~Wj?

/±_K9h k X;j? ~^± X— X/jW = /_ /X= /XK = * [j W~ ?~/ =jj _ =XJ?X!XK_?/ • Wj%j?Wj?Kj ~! /' j v

;_^jh 4 ' j ;_^j X= v f s htm„shsu h

mht E-^

mhr ±

mhu H

mEa ±

±

OC0

OCV D

shu °

OCE ]

O Ynhc u uhc c chc r rhc p

•S3ks'Ly

BXJ^±j chmue 4'j !_K/~±* °v{B /'_/ /'j '_W±~?XK =jK/X~? j?j±J° —^=/ >j —^/X%XjW >° X? ~±Wj± /~ j*^_X\j D5£00\• !~± %j?j/±_/X?J _?W ?~?%j?j/±_/X?J %X~?=h °v{ X= K~?=/_?/ ~;j± •B

6 'j? /' X= !_K/~± X= _% % XjW /~ /'j '_W±~? XK =jK/X~? j?j±J°* /'j * ^ _ ? /X/° D 5qE • ¥

D*—RN0q]\k X= j*^_ [ X/' X? /'j ^?Kj±/_X? /Xj= !~± % j ? j /±_ /X? J _?W ? ~ ? % j? j /±_ /X? J %X~?=h

4'X= X= ='~[ ? X? B XJ^±j chmch y° ^=X?J - j/'~W vvv* /' j Wj%j?Wj?Kj ~ ! /'j ±jK~?E

VV


5.3.-1 :\Iethod III

In order to establish :\[ethod III in the Central calorimeter. we need to determine

a multiplicati\·e factor. k that must be applied to the signals from the hadronic

section in order equalize Ecad p for penetrating and non penetrating pions. \Ve have

determined this factor. and it is shown in Figure 5.1-l as a function of p of the golden

track. Gin~n our limited statistics. we do not see a significant p dependence of the k

value. The value is k == 0.81±0.0-l.

2

1.8 ;:---c

1.6 ,..

IA -

17 -

1

0.8

0.6 -

OA -

0.2 :-

0 J

--- I --- , --------~---~- i T ----

3.5 4 -'-5 5 5.5 6 6.5 7

p(GeV)/c

Figure -5.1-l: The factor. (k). that the hadrouic section energy must be multiplied by in order to equalize Ecorr/ p for penetrating and uonpenetrating pions. (k) is constant over p.

\Vhen this factor is applied to the hadronic section energy, the quantity Ecail p -

Eneutrail p is equal within the uncertainties for penetrating and non penetrating pions.

This is shown in Figure 5.15. By using ;\fethod III, the dependence of the recon-

66

= /±^ K /j W '_W ±~ ? j?j±J° ~? /' j = /_ ± /X? J %~ X? / ~! /' j ' _W ±~ ? ='~[j± X= j X— X?_/jW * _=

[j =_[ j_±Xj ± !~± /'j L ^J 8 %J±_Wj g _ ~ ±X— j/j ± T=jj B XJ^ ±j chr'h

m5W m z)* I p

] '

X w?/±Xj= A © " o ’ 1j_EX ghpgbs e b 1Z gh a ♦ c Z

%j?j/±_/X?J* cd%dmc

s m a n u c

w $±iL

)G Nm

- r Y 1Z E aYc p

e E ?~?%j?j/?X/X?Jh cd%dmc

! ±7 N mh ± I

s m a n u c

B XJ ^ ±j chmce D5q00\• !~± %j?j/±_/X?J _?W ?~?%j?j/±_/XXXJ %X~?= ['j? - j/'~W vvv X= ^=jWh 4 ' j %~/ ~?° X?K^Wj= %_±/XKj= [X/' —~—j?/_ >j/[jj? c _?W mc kj1AiKh 4 'j —j_?= ~! /'j W X=/±X>^ /X~?= _±j ?~/ =XJ?X!XK_?/° WX!!j±j?/ JX;j? /'j = /_ /X= /XK_ ^?Kj±/_X?/Xj=h

chu g~?K^=X~?=

6 j '_;j %±j=j?/jW /[~ — j/'~W= ~! W j /j ±— X? X? J /' j j?j±J° =K_j ~ ! /'j '_W±~?XK

=j K /X~ ? ~ ! /' j g j?/±_ K_ ~ ±X— j/j±h 6j = /^ W XjW /'j=j /[ ~ — j/'~W= %±j;X~^=° [ X/'

L ^ J 8 %J±_Wj /j=/>j_— W _ /_ * _ ? W !~^?W /' _ / - j/'~W v X? /±~W^Kj= ^?Wj=X±j_>j j!!jK/=

=^ K' _= /'j Wj%j?Wj?Kj ~! /' j ±jK~?=/±^K /jW j?j±J° ~ ! _ '_W ±~? ~? /'j = /_ ± /X? J %~X?/

~ ! /' j '_W ±~? ='~[j±h 6j !~^?W /'j =_— j j!!jK/= X? /' j g j?/±_ K_ ~ ±X— j/j± ['j?

rp


structed hadron energy on the starting point of the hadron shower is eliminated. as

we saw earlier for the Plug C'pgrade Calorimeter (see Figure 5.6).

u -12

10

8 :-

6 =-.. =-:?. -

fi I

~ I .JL i I I ' : I

penelrJling, 5<p<l5

0 -~~-.L------~~--~~------

30 _

20

15

10

-

5 ::--

0

0

!

r J

0

2 3

Eror/P

nonpenetrJting, S<p<lS i"

... 7

2 3

Eror/P

5

s

Figure 5.1-5: Ecarr/P for penetrating and nonper:.etrating pious when Method !II is used. The plot only includes particles with momenta between 5 aud 15 GeV / c. The means of the distributions are not significantly different given the statistical uncertainties.

5.--1 Conclusions

\Ye have presented two methods of determining the energy scale of the hadronic

section of the Central calorimeter. \\"e studied these two methods previously with

Plug Cpgrade testbeam data, and found that 1Iethod I introduces un<lesireable effects

such as the dependence of the reconstructed energy of a hadron on the starting point

of the hadron shower. \Ve found the same effects in the Central calorimeter when

6T

/' X= K_ X> ±_ /X~ ? — j/'~W [_= ^=jWh v? % _ ±/XK ^ _ ±* /'j ±jK~?=/±^K /jW j?j±J° ~! '_W±~?=

[ X/' c d • d mc k j2 iK ['XK' >jJX? ='~[ j±X?J X? /'j j jK /±~— _J?j/XK =jK/X~? ~! /'j

K_ ~ ±X— j/j ± X= =°=/j— _/XK_ ° ^ ? W j ±j= /X— _ /jW h Z^K' % _ ±/XK j= K_±±° — ~=/ ~! /'j j?j±J°

~! 7j /= _ / g , B h 8=X?J K_ X> ±_ /X~ ? - j/'~W vvv _;~XW= /' X= j!!jK/h

V0


this calibration method was used. In particular, the reconstructed energy of hadrons

with 5 < p < 15 GeY/c which begin showering in the electromagnetic section of the

calorimeter is systematically underestimated. Such particles carry most of the energy

of jets at CDF. Csing calibration :\[ethod III avoids this effect.

68

g q x L 4 w 0 V

zw 4 Z

Nx 15<—*N<: <5 N0RN> %£—1 *£ N N0<RS•> 96 5£*_<*5<*4 <N1 £••£*—*N1 q*% S q v *<*4 N>—S 1—— N>— ]<4>N■ 9RN 0qN>—0 9—5qR1— <N1 £••£*—*N1 —_—*NRq]]6 %<— q *% q *—^ 4—*—0q N<£* 40£^1 R• N>qN <1 :qS <]<q 0 ^<N> <NB ZL E- _] L_?K9

VCF Z /±~ ? J K~^%X?J K~?=/_? /

4 ' j !_K/ /' _ / 3 g , X= ?~?_>jX_? _?W X? /j ±_K /X~ ? = >j/[ jj? X/= J_^Jj >~=~?= _±j

%~==X>j j_W= /~ /[~ ^^X*^j j!!jK/=h x= X? 3 w , h /' j K~^%X?J K~?=/_? / K'_?Jj= [ X/'

/'j - j T— ~— j? /^— /±_?=!j±' ~ ! /' j X? /j±_K/X~? h 4 ' j 3g, K~^%X?J K~?=/_? /h q 1-j{B

X= JX;j? /~ ~ ±Wj± V ° q <' >°

[ 'j±j - j X= /'j — ~— j?/^— /±_ ? =!j ± TXhjhh /'j j?j±J° ~! /'j %±~>j' _?W 0<: X= /'j

?^— >j± ~! *^_±9 !_;~±= T_==^— jW /~ >j =X]'h qj±j* [j =jj /'j WX!!j±j?Kj >j/[ jj? 3 w,

_?W 3 g , h v? 3 w , h _= _ >_±j j jK /±XK K'_±Jj X= % ±~ > jW _ / ' XJ'j± _? W 'XJ'j± j?j±JXj=

EK~±±j=%~?W X?J /~ =' ~ ±/j ± _?W =' ~ ±/j ± W X=/_?Kj= E /' j = /±j? J /' ~ ! /'j j jK/±~— _J?j/XK

K~^%X?J X?K±j_=j=* > ^ / X? 3g,h _ G WjK±j_=j= [ X/' X?K±j_=X?J - jB x / =^!!XKXj?/° 'XJ'

;_^j= ~ ! - j■ q 1 >jK~— j= _ ±> X/±_ ±X° =— _* Xhjh* X?=XWj /'j % ±~ /~? * *^_±9= _±j ^?>~^?W h

4 ' X= X= 9?~[? _= q16S •N£ N<5 :0——%£S ~ ! /'j = /±~ ? J X? /j±_K /X~? h

4 ' j WjK±j_=j ~ ! q 1 [ X/' X?K±j_=X?J - j T=— _ W X= /_ ? K j =K_j' X— %Xj= _? X?K±j_=j ~!

q 1 [ X/' WjK±j_=X?J - j T_±Jj W X= /_? Kj =K_j'h 4 ' X= j_W= /~ /'j K~?Kj%/ ~! 5£]£0 5£**

: <* —S —* N ■ ?_— j° /' _ / *^_±9= K_? ? ~ / j]X=/ _= !±jj %_±/XK j=h x= /[~ *^_±9= _ ±j %^jW

_ % _ ± / * /' j % ~ /j? /X_ j?j±J° >j/[ jj? /'j— >jK~— j= _±Jj j?~^J' /' _ / X/ >jK~— j=

S r C m'

[ X/'

S V CE '

rb


CH.-\PTER 6

JETS

''A scientific truth does not triumph by curwincing its opponents and making them see the light. but rather because its opponents eventually die and a new generation grows up that is familiar with it." -~lax Planck

6.1 Strong coupling constant

The fact that QCD is nonabelian and interactions betwPen its gauge bosons a.re

possible leads to two unique effects .. -\.s in QED. the coupling t:onstant changes with

the Q2 (momentum transfer) of the interaction. The QCD coupling constant. nj(Q2).

is given to orclPr O(n;) by

., 12Ti nj ( Q-) = )!

(3.3 - '2.n1) In~\: • r.JCD

( 6.1)

with

(6.2)

where Q2 is the momentum transfer (i.e .. the energy of the probe) and n 1 is the

number of quark flavors (assumed to be six). Here. we see the difference between QED

and QCD. In QED, as a bare electric charge is probed at higher and higher energies

-corresponding to shorter and shorter distances - the strength of the electromagnetic

coupling increases. but in QCD, o:, decreases with increasing Q2• At sufficiently high

values of Q2, nj becomes arbitrarily small. i.e .. inside the proton, quarks are unbound.

This is known as asymptotic freedom of the strong interaction.

The decrease of as with increasing Q2 (small distance scale) implies an increase of

Q'.5 with decreasing Q2 (large distance scale). This leads to the concept of color con

finement, namely that quarks cannot exist as free particles . .-\s two quarks are pulled

apart, the potential energy between them becomes large enough that it becomes

69

j?j±Jj/XK_ ° !_;~±_>j /~ K ±j_ /j _ *^_±9 E_? /X*^_±9 %_X± !±~— /'j ;_K^^— * /'^= K ±j_ /E

X?J /[~ =j % _ ±_ /j '_W±~?=h 4 ' X= %±~Kj== X= 9?~[ ? _= :0q4S —*Nq N<£* ~ ± >q%0£*<CqN<£*B

6 'Xj K~?!X?j— j?/ X= =/X _ ? j]%j±X— j?/_ !_K/ ±_ /'j± /' _ ? _ /' j~ ±j /XK_ %±jWXK/X~?*

X/ X= [ XWj° _KKj% /jW =X?Kj ?~ !±jj *^_±9= ~ ± J^~?= '_;j >jj? ~>=j±;jW X? ?_/^ ±j h

VCE q _W±~?X\_/X~?

B~± - j xH ; < c /'j ;_^j= ~! _ G _ ±j =— _* =~ /' _ / % j ±/^ ±> _ /X~ ? /'j~±° K_?

>j _%% XjW h B~± - j ~! ~ ±Wj± Q ± OyB q q X= _±Jj* _?W % j ±/^ ±> _ /X~ ? /' j~ ±° K_??~/ >j

_%%XjW h 4 '^=* =j— XEj— %X±XK_ —~Wj= ~! '_W ±~? X\_ /X~? '_;j >jj? Wj;j~%jWh qj±j*

[j >±Xj!° Wj=K±X>j /'j — ~Wj 9?~[? _= /'j = /± X? J — ~Wjh

6 'j? _ * ^ _±9 _?W _? /X* ^ _ ±9 _±j %^jW _% _ ±/* /'j K~~± !XjW >j/[ jj? /'j— X=

±j!j±±jW /~ _= _ NK~~± = /± X? J N ~± NK~~± /^ > j hN 4 'j % ~ /j? /X_ >j/[ jj? /'j *^_±9

_?W _ ? /X* ^ _ ±9 K~? /_X?= _ /j ±— X?j_± X? /' j W X=/_?Kj* 0B =j% _±_ /X? J /' j *^_±9 _?W

_? /X* ^ _±9 h

b m v0 B Trhn'

4 '^= _= /'j ++ _ ±j =j%_±_ /jW * /'j %~/j? /X_ j?j±J° >j/[ jj? /'j— ±X=j= X?j_±° [X/'

0B x / =~— j =j% _±_ /X~ ? T< F !— '* X/ /_9j= j== j?j±J° /~ K ±j_ /j _ ++ % _ X± !±~— /'j

;_K^^— _? W '_;j /[~ =' ~ ±/j ± =/±X?J= /'_? /~ K~?/X?^j /' j =j%_±_ /X~? h

rhn 6♦' _ / X= _ 7j /.

4 ' j !±_J — j? /_ /X~ ? %±~Kj== '_%%j?= ~? /' j /X— j =K_j ~ ! ms* BG =jK~?W=h 4'^=*

* ^ _±9 = _?W J ^~?= %±~W^KjW X? 'XJ' j?j±J° K~X=X~?= '_W ±~? X\j X— — jWX_ /j ° >j!~±j

/±_;jX?J _?° =XJ?X!XK_?/ W X=/_?Kj _[_° !±~— /' j X? /j±_K /X~? %~X? /TXhj hh >j!~±j j?K~^?E

/j ±X? J /'j W j /j K /~ ±' h 4'j° ='~[ ^% X? /'j W j /j K /~ ± _= _ N=%±_°N ~! ' _W ±~ ? = ['XK'

±~^J'° !~~[ /'j ~±XJX?_ W X±jK /X~? ~! /'j * ^ _ ±9 ~± J^~?h 4 'X= K~jK/X~? ~ ! % _ ±/XE

Kj= X= K_jW _ 7j / h 4'^=* !~± _? j]%j±X— j?/_X=/* _ 7j / K_? >j /'~^J'/ ~! _= =X— %°

ps


energetically favorable to create a quark-antiquark pair from the vacuum. thus creat

ing two separate hadrons. This process is known as fragmentation or hadroni.::ation.

\\"hile confinement is still an experimental fact rather than a theoretical prediction.

it is widely accepted since no free quarks or gluons have been observed in nature.

6.2 Hadronization

2 For Q >> .\QCD· the values of 0.1 are small. so that perturbation theory can

be applied. For Q2 of order .\ QCD. O:s is large. and perturbation theory cannot be

applied. Thus, semi-empirical models of hadronization have been dewloped. Here.

we briefly describe the model known as the string model.

\\"hen a. quark and antiquark a.re pulled apart. the color tieid between them is

referred to as a ·'color string .. or .. color tube... Tlw potential between the quark

and antiquark contains a term linear in the distance. r. sPparatin~ the quark and

antiquark.

\ · = kr. (6.:3)

Thus as the qq are separated. the potential energy between them rises linearly with

,-_ At some separation ("" 1 fm), it takes less energy to create a qq pair from the

vacuum and havP two shorter strings than to continue the separation.

6.3 What is a jet"?

The fragmentation process happens on the time sea.le of 10-23 seconds. Thus.

quarks and gluons produced in high energy collisions hadronize immediately before

travelling any significant distance away from the interaction point(i.e .. before encoun

tering the detector). They show up in the detector as a ··spray .. of hadrons which

roughly follow the original direction of the quark or gluon. This collection of parti

cles is called a jet. Thus, for an experimentalist. a jet can be thought of as simply

70

_ K~ X— _/jW K~ jK/X~? ~! K'_±JjW _? W ?j^ /±_ ' _ W ±~ ? = j— j±JX?J !±~— /'j X? /j ±_K /X~ ?

%~X?/h 3 ^ _ ±9 7j /= [j±j !X±=/ ~>=j±;jW X? j4j N K~ X= X~?= >; /' j - _±9Ev g ~ _> ~ ±_ /X~?

_ / Z)xg X? mbpc DmtVh k ^~? 7j /= [j±j !X±=/ ~ > =j ±; jW X? mbpb >° j]%j±X— j?/= _ / /'j

—H—H K~ XWj± L w 4 0 x _ / ,wZ2 DmbVh 4 ' j 8xE g ~ _> ~ ±_ /X~ ? _ / g w 0 P ~>=j±;jW /' j

!X±=/ 7j /= _ / _ •• K~ XWj± X? mbta DasVh

4'j %±~Kj== ~! * ^ _±9 = '_W±~?X\X?J X? /~ — j=~?= _ ? W >_±°~?= [ 'XK' K_? >j — j_=^ ±jW

X? _ W j /jK /~ ± X= /°% XK_ ° Wj=K±X>jW >° _ !±_J — j? /_ /X~ ? !^?K/X~? % _ ±_— j/±X\jW _= !~~[=

SF E A ' ?yC { f x A I E # ) Trhu'

['j±j y° C { X= /'j % ±~>_> XX/° /' _ / _ 7j / !±_J— j?/ [ X j?W ^% [ X/' _ !±_K/X~? K ~ ! /'j

~±XJX?_ % _ ±/~ ? j?j±J° _?W * _?W xN _ ±j K~?=/_? /=h

rhu - j_=^±X?J 7j /= X? 'XJ' j ? j ±J ° K~X=X~?=

8=^_°* _ 7j / X= Wj!X?jW _= /'j K~jK/X~? ~! % _ ±/XK j = /' _ / !_ [ X/' X? _ K~?j [ X/'

~%j?X?J _?J j I j— j±J X?J !±~— /' j X? /j±_K /X~? ; j ±/j] h 4 °%KX_ ;_^j= ~! I B ['j?

j]%±j==jW X? /j±— = ~ ! _? X?/j±;_ X? 0$B £ =%_Kj ° I m Q \} 0 $ j E/E xd.a'h ±_?Jj !±~— shnE

shph v! /'j K'~=j? I ;_^j X= _±Jj* /' j K~?j — _° >j K ~ ? /_ — X? _ /jW [ X/' %_±/XKj= /' _ /

'_;j ?~ /' X?J /~ W~ [ X/' /'j !±_J— j?/X?J ~> 7jK/h v! I X= =— _* =~— j 7j / !±_J— j?/=

— _° >j ~ K_ /jW ~ ^ /=XWj /'j K~?jh B ^ K /^ _ /X~ ? = X? /' j 7 j / j?j±J° K~? /_ X?jW [ X/' X? /'j

7j/EWj!X? X?J K~?j !~±— _? X±±jW^KX>j K~— %~?j?/ ~ ! /' j j?j±J° ±j=~ ^ /X~? ~! /' j 7j /

Wj/jK/~±h

qXJ' ±j=~ ^ /X~? ' _W ±~? K_ ~ ±X— j/±° [X >jK~— j X?K±j_=X?J° X— % ~ ±/_? / X? /'j

— j_=^±j— j?/= ~ ! 7j /= _= /'j j?j±J° !±~? /Xj± X= % ^ =' j W /~ ' XJ'j± ;_^j= ~! 6\uB ZX?Kj

'XJ' j?j±J° 7 j / = _±j — ~±j K~X— _/jW /' _ ? ~[ j?j±J° 7j /= * /'j X— X/_ /X~ ? = X— %~=jW >°

7j/EWj!X? X?J _ J ~ ±X/' — = WjK±j_=j [ X/' X?K±j_=X?J j?j±J° h

6 X/' K^ ±±j ? / K_ ~ ±X— j/j ± /jK'?~~J°* /'j ±j* ^ X±j— j? /= !~± ' XJ' ±j=~^/X~? ' _W ±~ ?

K_~±X— j/±°* '~[ j;j±* _ ±j j]_K/° ~ % % ~ =X/j ~! /' ~ =j ?jjWjW !~± ' XJ' ±j=~^/X~? jjKE

pm


a collimated collection of charged and neutral hadrons emerging from the interaction

point. Quark jets were first observed in e.,.e- collisions by the 1Iark-I Collaboration

at SL\C in 1975 [18]. Gluon jets were first observed in 1979 by experiments at the

e-e- collider PETRA at DESY [19]. The C..\2 Collaboration at CERX observed the

first jets at a pp collider in 1982 (20].

The process of quarks hadronizing into mesons and baryons which can be measured

in a detector is typically described by a fragmentation function parametrized as follows

(6.-1)

where D(.:) is the probability that a jet fragment will end up with a fraction .: of the

original parton energy and n and S arf" constants.

6.-1 ~[f',1.S11ring jets in high energy collisions

[sually. a jet is defined as the collection of particles that fall within a conP with

opening angle R emerging from the interaction vertex. Typcial \·;dues of R. when

expressed in terms of an interval in ,,. o space (R = J j.,,:! + ,j.9:!). range from 0.3-

0.7. If the chosen R \·alue is large, the cone may be contaminated with particles that

have nothing to do with the fragmenting object. If R is small. some jet fragments

may be located outside the cone. Fluctuations in the jet f'nergy contained within the

jet-defining cone form an irreducible component of the energy resolution of the jet

detector.

High resolution hadron calorimetry will become increasingly important in the

measurements of jets as the energy frontier is pushed to higher values of ~- Since

high energy jets are more collimated than low energy jets, the limitations imposed by

jet-defining algorithms decrease with increasing energy.

\\'ith current calorimeter technology, the requirements for high resolution hadron

calorimetry, however, are exactly opposite of those needed for high resolution elec-

71

/±~ — _J ? j /XK K_ ~ ±X— j/±° DVV Tj?j±J° — j_=^±j— j?/ ~ ! jjK/±~?= _ ? W %'~/~?='h 4 'j

H w8 Z g ~_>~±_ /X~? K^±±j? /° ~ % j ±_ /j = /'j ' XJ'j=/E±j=~^/X~? ' _W ±~ ? K_ ~ ±X— j/j± X?

/' j [ ~±W DEFV* > ^ / %_°= _ %±XKj !~± /' _ / [ X/' _ — _±J X?_ j jK/±~— _J?j/XK j?j±J° ±j=~Ê

j]Kjj? / j jK/±~— _J?j/XK j?j±J° ±j=~ ^ /X~? * _ / /' j j]%j?=j ~! ' _W ±~? XK ±j=~ ^ /X~? h

Q ?j =~^/X~? [ 'XK' X= >jX?J K~?=XWj±jW X? /'j K~? /j] / ~! _ %~==X> j T>^ / ^?X9j°'

!^ /^ ±j X?j_± —H—H K~XWj±* X= _ — j /' ~ W K_jW /'j D*—046 z]£^ ,—N>£% Tw B - 'h v?

/' X= — j/'~W * X? !~ ±— _/X~? !±~— /' j K_ ~ ±X— j/j± =°=/j— X= K~— >X?jW [X/' /' _ / !±~—

_? ^ % =/±j_— /±_K9j± =°=/j— h 4 ' j — ~— j?/_ ~! /' j K'_±JjW 7j / !±_J— j?/=* — j_=^±jW

[ X/' 'XJ' %±jKX=X~? >° /'j — _J ? j /XK /±_K9 X?J =°=/j— * =j±;j _= _ !X±=/E~±Wj± j = /X— _ /j

~ ! /' j 7j / j?j±J°h 4 ' j K_ ~ ±X— j/j± =XJ?_= _±j ^=jW /~ ~>/_X? =jK~?WE~±Wj± K~ ±±jK /X~?=

/~ /' _ / j?j±J°* K_^=jW >° /'j ? j ^ /±_ 7j / K~— %~?j?/ T<=h i;“= _? W ?j^/±~?='h 6 X/'

— j/' ~ W = ~ ! /'X= /°%j* =j;j±_ ) w L j]%j±X— j?/= X— %±~;jW /'j ±j=~ ^ /X~? ~! 7j /= !±~—

H EW jK_° !±~— < maR /~ j_±? W _ /_ _?W _ = X— ^ _ /X~ ? ;j±° =X— X_± /~ /' _ / Wj=K±X>jW X? ZjK/X~? chahuh

8 =X?J /'j — j/'~W Wj=K±X>jW X? ZjK/X~? chahuh [j !X±=/ >^X/ NX>±_±Xj=N ~! 7j / =XJ?_

W X= /± X> ^ /X~ ? = h c7j/ Tj*^X;_j?/ /~ D g : £* X? w *^_/X~? chu'h !~± 7j /= ~ ! _ ;_±Xj/° ~ ! j?E

j±JXj=* ±_?JX?J !±~— nsEmsss k j1 h B~± _ JX;j? 7j / ~ ! _ Kj±/_X? !X]jW j?j±J°* jhJhh mss

k j1 * /' j j]%j±X— j?/_ %X~? = XJ?_ W X= /± X> ^ /X~ ? = [j±j ^=jW T_J_X? X? /'j =_— j [_°'

/~ W j /j ±— X? j /'j N— j_=^±jW &= K _ ~ ±X— j /j ± j?j±J° !~± X?WX;XW^_ K'_±JjW 7j / !±_J— j?/=*

YK'_±JjWE 4 'j ?j^ /±_ 7j / K~— %~?j?/ ~ ! /'j FOO k j1 7j /* w ?j /±_X± !~^?W >° =^ > E

/±_ K /X? J wK'_±JjW !±“— /'j _;j±_Jj ;_^j ~! /'j W <—N W X=/±X>^ /X~? !~± mss kj1 7j /= * Xhjh*

w ?j^/±_X f Tc7j/' E HK'_±JjWE 4 'j j?j±J° !~^?W [ X/' /'j wB- !~± /' X= % _ ±/XK^ _ ± 7j /

[_= K_ K^ _ /jW _=

[ 'j±j D N< f m*a* B B BS { ±j%±j=j?/ /' j —€q5N j?j±JXj= ~! /'j K'~=j? 5>q04—% 7j / !±_JE

/X~? e RO X U I mi h \ Z \ D B g _ ~ ±X— j/j±= >jX?J >^X/ !~± /'j )qg j]%j±X— j?/= j— %'_=X\j

STrhc'

pa


tromagnetic calorimetry [6] (energy measurement of electrons and photons). The

ZECS Collaboration currently operates the highest-resolution hadron calorimeter in

the world [21J, but pays a price for that with a marginal electromagnetic energy resolu

tion: a/ E = 18%/ ft. Calorimeters being built for the LHC experiments emphasize

excellent electromagnetic energy resolution. at the expense of hadronic resolution.

One solution which is being considered in the context of a possible (but unlikely)

future linear e-e- collider. is a method called the Enagy Flow .\letlwd (EF:\I). In

this method. information from the calorimeter system is combined with that from

an upstream tracker systrm. The momenta of the charged jet fragments. mea'-iured

with high precision by the magnetic tracking system. serve as a first-order estimate

of the jet energy. The calorimeter signals are used to olitaiu st•cond-ordt•r corrections

to that energy. caused by the neutral jet component ( ~-s. I<0s and neutrons). \\"ith

methods of this type. several LEP experiments improwd the resolntion of jets from

Z-decay from--... 12Yc to "'9'X. \\"e have studied the merits of this method nsing tht>

same testbeam data. and a simulation very similar to that drscribed in Section 5.2.--l.

Csing the method described in Section 5.2.--l. we first built ··libraries"" of jet signal

, distribntions. Sjet (equivalent to EJ;~on in Equation 5.--l). for jets of a variety of en

ergies. ranging from 30-1000 Ge\·. For a given jet of a certain fixed energy, e.g., 100

Ge\·, dtP experimental pion signal distributions \Vere used (again in tht-> same way)

to determine the "measured'' ca!orimeter energy for indi\·idual charged jet fragments.

Echarged· The neutral jet component of the 100 GeV jet, Eneutral, was found by sub

tracting £charged from the average value of the Sjet distribution for 100 Ge\· jets, i.e.,

EneutraJ = (Sjet) - £charged· The energy found with the EF~I for this particular jet

was calculated as

rn

£EF~! = L £, + £neutral

i=l

(6.5)

\vhere E,(i - 1, 2, ... m) represent the exact energies of the chosen charged jet frag-

-·) , _

—j?/=h

4 'j ±j_/X;j j!!jK/ ~! /'j wB- ~? /' j 7j / j?j±J° ±j=~^/X~? [_= Wj/j±— X?jW >°

K~— %_±X?J /'j !±_K/X~?_ [ XW/'= ~! /'j c 7 j / _?W w j ! — W X=/±X>^ /X~?=h 4'j X—%±~;jE

—j?/ ~ ! /'j 7j / j?j±J° ±j=~^/X~? !~^?W /' X= [_° X= ='~[? X? BXJ^±j V h Fh , j/_X= ~!

/'X= = /^ W ° _±j Wj=K±X>jW X? _ %_%j± /' _ / [_= ±jKj?/° _KKj%/jW !~± %^>XK_/X~? X? lR*

5]—q0 [*1N0RS—*N1 q*% ,—N>£%1 <* k>61<51 I—1—q05> DaaVh x %±j%±X? / ~! /'X= %_%j± X=

K~?/_X?jW X? x%%j?WX] gh

w?j±J° Tkj1' # E-5' FOOO ~ ~ vQQ msss

■ _ f / * f m kj1iK h _ f rh k>5 f a kj1iK © _ f rh %Yh f n kj1iK

# _ iw f psdZi°Aw U W0< ’ E+ Qiw f un&Mi&im4+E n&" I# s iw f T5 + i1 w S t Y { g,B L^J I

_ f r* %>0m ' kj1iK

q£

»6B

lQ[g h

l

OCEO s hs c O OCEOshmc shms s hm c shms s hs c s

> Ls5BXJ^±j rhme 0j_/X;j X—%±~;j—j?/ ~! /'j 7j / ±j=~^/X~? >° ^=X?J /'j w?j±J° B~[ -j/'~W* _= _ !^?K/X~? ~! /'j 7j/ j?j±J°h 0j=^/= ~! -~?/j g_±~ =X—^_/X~?= [X/' WX!!j±j?/ %_±_—j/j±j K'~XKj= 4 'j >_K9 WX_—~?W= [j±j ~>/_X?jW ^=X?J /j=/>j_— W_ /_ !±~— /'j g,B L^J 8%J±_Wj K_~±X—j/j±h Zjj /j]/ !~± Wj/_X=h

rhuhm g~?K^=X~?=

4'j j]%j±X— j?/_ W _ /_ _?W /'j ±j=^ /= ~ ! =X— ^_/X~?= >~/' ='~[ /' _ / /'j wB-

~!!j±= _? X— %±~;j— j?/ X? /'j 7j / j?j±J° ±j=~^/X~? ~! <nsR h L~~± K_~±X— j/j± =°=/j— =

>j?j!X/ — ~±j /' _? J~~W K_~±X— j/j± =°=/j— =* _?W _ = /±~ ? J — _J?j/XK !XjW _=~ 'j%=h

pn


ments.

The relative effect of the EF~I on the jet energy resolution was determined by

comparing the fractional widths of the Sjet and EEFM distributions. The improve

ment of the jet energy resolution found this way is shown in Figure 6.1. Details of

this study are described in a paper that was recently accepted for publication in Nu

clear Instruments and i\lethods in Physics Research [22] . .-\ preprint of this paper is

contained in Appendix C.

...... ~ ...., C:

. 9 '5 -:;: ~ ,_ ~ .-, '-0

ti ::: u ;,. 0 ,_

.§ u

-~ ,: 1j

0:::

Energy (GeV) -

60 JO 50

. 50r- .

~ -'I)~

.1J

20

10 a)

0 0.20 0.15

JOO !COO oo

• a= f:. P1,c = I GeV/c • a=6.pbc=:!GcV/c • a= 6. Pi,,,= 3 UeV/c , a= 3. p1,.. = I Ge\'/c ·

• r. . •: !

0.10 0.05

t

0 0.2')

JO

- 11\/E

50 100 1000 oo

.... cr/E = 70%!·/E + 5"<: : l . ~ cr/E = 43'.l·t'/E + 3''c I 1

- I ..... cr/E = 100<:f/'i E + K% ! • CDFPlu!! 1

~ I

a=6.p,,,_=.:GeV/c1 .. I

' j j

b)

0.!5 0.IO 0.05 I)

Figure 6.1: Relative improvement of the jet resolution by using the Energy Flow Method, as a function of the jet energy. Results of Monte Carlo simulations with different para.metere choices The black diamonds were obtained using test beam data from the CDF Plug lipgrade calorimeter. See text for details.

6.4.1 Conclusions

The experimental data and the results of simulations both show that the EF:\f

offers an improvement in the jet energy resolution of -30'7c. Poor calorimeter systems

benefit more than good calorimeter systems, and a strong magnetic field also helps.

i3

v/ X= _=~ X— % ~ ±/_ ? / /~ ? ~ /j /' _ / /'j w B- W~j= ?~/ [~±9 _= [j _ / ' XJ' j?j±JXj= _=

_ / ~[ j?j±JXj=h x/ 'XJ' j?j±JXj=* /'j ' _W ±~ ? XK K_ ~ ±X— j/j± ±j=~^/X~? X= W ~ — X? _ /jW

>° !^K /^_/X~?= /' _ / ±j=^ / !±~— /'j WX!!j±j?/ K_~ ±X— j/j± ±j=%~?=j /~ j— _ ? W ?~?Ej—

j?j±J° W j% ~ =X/h 4'j=j ! ^ K /^ _ /X~ ? = _±j ?~ / _WW±j==jW* ?~± K^ ±jW >° /' j w B - h


It is also important to note that the EF~I does not work as well at high energies as

at low energies. At high energies. the hadronic calorimeter resolution is dominated

by fluctuations that result from the different calorimeter response to em and non-em

energy deposit. These fluctuations are not addressed. nor cured by the EF~I.

7-l

g q x L 4 w 0 p

h5ut6— .rt dar*)5d 856uw r. d—5 < ug8 f lrhrgh ud d—5

.5tn2iul d5sudtrg

phm v? /±~ W ^ K /X~ ?

4'j v4 _? W ' >~=~?= '_;j >jj? j]/j?=X;j° =/^W XjW _ / g , B /' ±~^J' /' j X± j%/~?XK

WjK_° — ~Wj=h q A ¥N —RB :$B_ _? W ' *1 —— B* \ j = XJ ? _ /^ ±j X? /'j Wj/jK /~ ±= h 4 ' j '_W±~? XK WjK_° ~! /'j 8♦ _ ? W ' B '~[j;j±*

'_= >jj? ~>=j±;jW _ / g , B X? ~?° /[~ ;j±° =%jKX!XK K_=j=h 4 ' j '_W±~?XK WjK_° ~! /'j

[b '_= >jj? XWj?/X!XjW X? /~ % *^_±9 =_— %j= DanVh _?W /'j =%jKX!XK WjK_° K'_??jh

H * 1 99B ^X= >jj? ~>=j±;jW X? 'XJ' k" — ^~? W _ /_ =_— %j= DauVh v/ [~^W >j ^=j!^ /~

j] /j?W /'j=j = /^ W Xj= _?W XWj?/X!° f $ ' ' _W ±~ ? XK WjK_°= X? _ — ~±j Jj?j±_ [_°h ?_—j°

X? _ =_— %j ~ ! W X7j / j;j?/=h 6 'Xj X/ X= ?~/ %~==X> j /~ XWj?/X!° '_W±~?XK WjK_°= ~! 8 A=

_? W H = !±~— =^K' _? j;j?/ =_— %j ~? _? j;j? /E>°Ej;j? / >_=X=* X/ ='~^W >j = /_ /X= /XK_ °

%~==X>j /~ XWj? /X!° /'j=j WjK_°= =X?Kj /'j 3 g , >_K9J±~^?W X= X? /±X?=XK_ ° _ =— ~~/'

Y !^?K/X~? ~ ! /' j W X7j / X?;_±X_? / — _==h vWj? /X!° X?J _ f $ ' — _== %j_9 _>~;j /'j 3g,

>_K9J±~^?W [~^W =j±;j =j;j±_ %^±%~=j=h

B X±=/* =^K' _ %j_9 [~^W %±~;XWj _? X— % ~ ± /_ ? / '_?W j !~± ^ ? W j±= /_? W X? J /'j 7j /

j?j±J° =K_jh 4 ' j 7j / j?j±J° =K_j '_= >jj? W j /j ±— X? jW X? /' j %_=/ T!~± /' j /~% —_==

— j_=^±j— j?/* !~± j]_— %j' >° ^=X?J =_— %j= ~ ! j;j?/= X? ['XK' _ 7j / _ % % j _ ±= [X/' _

% ±~— % / %'~ /~? ~ ± _ H _?W %j±!~ ±— X?J _ N 7j /E% ' ~ /~ ? >__?KX?JN ~± £H E7j / >__?KX?J£

%±~KjW^±j Dac* ar* apVh vWj? /X!° X?J /' j Q b \ ' % j_9 X? /'j W X7j / X?;_±X_?/ — _== =%jK/±^—

[~^W %±~;XWj _ ;j±° Kj_? — j/' ~ W ~! W X±j K /° W j /j ±— X? X?J /' j 7j / j?j±J° =K_j* =X?Kj

/'j Qb _?W H — _==j= _±j 9?~[ ? /~ J ±j_/ % ±jK X=X~? h B ^ ±/'j±— ~±j * _? _ > XX/° /~ XWj?/X!°

q ♦= _?W H= X? /' j 7j /E 7j / X?;_±X_? / — _== =% j K /±^ — [~^W /±^ ° X?W XK_/j /' j _> XX/° /~ W~

£7j / — _== =%jK/±~=K~%°£ _ / ' _W ±~ ? K~XWj±=h 4 ' X= K~^W %±~;XWj _ — j_?= !~± ~~9X?J

pc


CHAPTER 7

SEARCH FOR T\VO-JET DEC.-\Y OF THE tr .-\~D Z BOSO:\"S .-\T THE

FER.\IIL.-\8 TEY.-\TRO:\'

7.1 Introduction

The tr and Z bosons have been extensively studied at CDF through their leptonic

decay mo<les. tt · -r ev. µv an<l Z -+ ee. µµ. Such decays produce a dean and easily

recognizable signature in the detectors. The hadronic decay of the tr and Z. however.

has been observed at CDF in only two very specific cases. The hadronic decay of the

l r has lwen identified in top quark samples [23]. and the specific dPcay chauuf'l.

Z-+ bb. has been observed in high Pr muon data samples [2-l]. [t woulcl be useful to

extend thesP st u<lies and identity H '/ Z hadronic decays in a more ~t'rwral way. namely

in a sample of dijet events. \\.hile it is not possible to identify hadronir'. decays of u·s

and Zs from such an event sample on an event-by-event basis. it should be statistically

possible to identify these decays since the QCD background is intriusically a smooth

, function of the dijet im·ariant mass. Identifying a tr/Z mass peak abon• the QCD

background would serve several purposes.

First, such a peak would provide an important handle for understanding the jet

energy scale. The jet energy scale has been determined in the past (for the top mass

measurement, for example) by using samples of events in which a jet appears with a

prompt photon or a Z and performing a ··jet-photon balancing" or ··Z-jet balancing"

procedure [25, 26, 27]. Identifying the tV/Z peak in the dijet invariaut rna:;s spectrum

would provide a very clean method of directly determining the jet energy scale, since

the n· and Z masses are known to great precision. Furthermore. an ability to identify

ivs and Zs in the jet-jet invariant mass spectrum would truly indicate the ability to do

"jet mass spectroscopy"' at hadron colliders. This could provide a means for looking

75

!~± ?j[ %_±/XK j= ['XK' WjK_° '_W±~? XK_° ~ ± [ 'XK' WjK_° X?/~ q A= _?W H = TjhJhh /'j

qXJJ= >~=~?* X! 0*U l a— +E'h ZX?Kj /'j > ±_?K' X?J ±_ /X~ !~± '_W±~?XK WjK_° ~! /'j

X? /j ±— jW X_ /j ;jK/~± >~=~?= X= — ^K' _±Jj± /' _? !~± j%/~?XK WjK_°* /'j±j X= _=~ _

> j //j ± K'_?Kj ~! XWj?/X!° X?J _ ±_±j %±~Kj== X?;~;X?J /'j=j — _==X;j %_±/XKj= /' ±~^J'

'_W±~? XK WjK_° K'_??j= _= ~%%~=jW /~ j% /~?XK ~?j=h

, ^±X?J 4 j;_/±~? 0 ^? vgh _ ~[ E/'±j='~W W X7j / /±XJJj± [_= ^=jW /~ ±jK~±W mhb % > *F

~ ! W _ /_ h x %%±~] X— _/j° n — XX~? /[ ~E7j/ j;j?/= [j±j ±jK~±WjW X? ['XK' /'j UP ~!

j_K' 7j / [_= J ±j_ /j ± /' _? ma kj1Nh 4 'j=j W _ /_ [j±j %±j;X~^=° ^=jW /~ =j_±K' !~±

'_W ±~? XK f $ ' WjK_°= X? /'j 7j /E 7j / X?;_±X_? / — _== W X=/±X> ^ /X~ ? _= Wj=K±X>jW X? Datzh

qj±j* [j ±j;Xj[ ±jj;_?/ >_K9J±~^?W X? !~ ±— _/X~? _? W ±j%j_/ /'j _?_°=X= ^=X?J _ ?j[

_> =~ ^ /j 7j / j?j±J° =K_j K~±±jK/X~? h

pha )Nxa 0 j=^/

4 'j )♦xa j]%j±X— j? / ±j%~ ±/jW _ %j_9 X? /'j W X7j / X?;_±X_?/ — _== =%jK/±^— * _>~;j

/'j =— ~ ~ /' 3 g , >_K9J±~^?W DabVh 4 'j ~K_/X~? ~ ! /' j %j_9 K~±±j=%~?WjW ?XKj° [ X/'

/'j f _? W H — _==j=h

4 'j uhp „ sha % > *F =_— %j ~ ! W _ /_ ^=jW X? /'j _?_°=X= [_= K~jK/jW [ X/' _ /[~E

j;j Kj? /±_ W X7j / /±XJJj±h x/ /'j !X±=/ /±XJJj± j;j* j?j±J° [_= =^— — jW ~;j± bs“ X?

£B 4[ ~ =^K' =^— = _ / ~%%~=X/j _\ X— ^/' * j_K' [ X/' U P 1 mp k j1 T!~± /'j N~[ — _==

/±XJ J j±N' ~ ± U P l mn k j1 T!~± /'j N;j±° ~[ — _== /±XJ J j±N ' _?W X? K~X?KXWj?Kj [ X/' _

>j_— E>j_— X? /j ±_K /X~? TWj/j±— X?jW >° 4 Q B Wj /jK /~ ±=' [j±j ±j*^X±jWh x/ /'j =jK~?W

/±XJJj± j;j* 7j / U P [_= Wj /j ±— X?jW [ X/' _ ±jK /_? J ^ _ ± [X?W~[ ~ ! =X\j x 2 ] x ~ f ps“

] pc“h 4[ ~ =^K' 7j /= _ / ~%%~=X/j _\ X— ^/' T[ X/' X? ns“' _ ? W [X/' U P 1 mn kj1 T!~± /'j

N~[ — _== /±XJJj±£ ' ~± D " 3 FO k j1 T!~± /' j N;j±° ~[ — _== /±XJJj±£ ' [j±j ±j*^X±jWh

P~ /±_K9 ±jK~?=/±^K /X~? [_= %j±!~±— jW* _? W ~?° K_~±X— j/j± X?!~±— _/X~? [_=

±j_W ~ ^ / X? ~ ±Wj± /~ 9jj% /' j ±j_W~^ / /X— j _? W j;j?/ =X\j =— _h 6 X/' /'j N~[

— _== /± XJ J j ±£ _? W N;j±° ~[ — _== /±XJJj±*£ uhrr % > *F _?W shct % > *F [j±j K~jK/jW*

pr


for new particles which decay hadronically or which decay into irs and Zs (e.g .. the

Higgs boson, if mu > 2rnw ). Since the branching ratio for hadronic decay of the

intermediate vector bosons is much larger than for leptonic decay. there is also a

better chance of identifying a rare process involving these massive particles through

hadronic decay channels as opposed to leptonic ones.

During Tevatron Run IC. a low-threshold dijet trigger \Vas used to record 1.9 pb- 1

of data. .-\.pproximately 3 million two-jet events were recorded in which the Er of

rach jet was greater than 12 Ge\·. These data were pre\·iously 11st>d to search for

hadronic H"/Z decays in the jPt-jet irH"ariant mass distribution a.s described in [28].

Here. we review relPvant backgro11nd information and repeat the analysis using a new

absolutP jet energy scale correction.

7.2 C.-\.:2 Result

The C .-\.2 experiment reported a pPak in the dijf't invariant m,L-;s spectrum. abovf'

the smooth QCD background [29]. The location of the peak corresponded nicely with

the u· and Z masses.

The -L 7 ± 0.2 pb- 1 sample of data used in the analysis was collected with a two

level central dijet trigger. .-\.t the first trigger level. energy was summed over 90° in

o. Two such sums at opposite azimuth, each with Er > 17 GeV (for the ··low mass

trigger") or Er > 13 Ge\. ( for the ·'very low mass trigger") and in coincidence with a

beam-beam interaction (determined by TOF detectors) were required ... -\.t the second

trigger level. jet Er was determined with a rectangular window of size J..0 x ~o = T0°

x 15°. T \VO such jets at opposite azimuth ( within 30°) and with Er > 13 Ge\· ( for the

·'low mass trigger") or Er > 10 GeV (for the ·'very low mass trigger"') were required.

:,.;o track reconstruction was performed, and only calorimeter information \Vas

readout in order to keep the readout time and event size small. \Vith the --low

mass trigger" and "very low mass trigger," -l.66 pb- 1 and 0.58 pb- 1 were collected,

TG

±j=%jK/X;j°h x 7j / _ J~ ±X/'— ^=X?J _ K~?j =X\j ~ ! sht [_= _%% XjW /~ _ j;j?/= %_==X?J

/' j )j;j E /±XJJj±* _? W /'j 7j /= X? j_K' j;j?/ [j±j ~ ±Wj±jW _KK~±WX?J /~ WjK±j_=X?J

D N B

4 'j !~~[X?J ~!!X?j ±j*^X±j— j?/= [j±j _%% XjW /~ j;j? /= %_==X?J /'j )j;j a

/±XJJj±e

■ Eass ±? — d K d ass —— [ 'j±j C X= /'j ~?J X/^W X?_ j;j?/ ;j±/j] %~=X/X~? h 4'j

j;j?/ ;j±/j] [_= Wj/j±— X?jW >° /'j 4 Q B Wj/jK/~ ±h

■ ’K~=OXhE ’ d OCV ['j±j )]<j /'j %~_± _?Jj= ~! 7j / F _? W E h

h D3 d as k j1 ['j±j D $ X= /'j UP ~ ! /' j /' X±W 7j / h 4 ' X= ±j*^X±j— j?/ ±j7jK/=

j;j?/= [ X/' — ~±j /'_? E 7j /= h

■ :0■* = tsR ~± : ] S = tsR [ 'j±j iz ;E _ ±j /' j j jK /±~— _J?j/XK j?j±J° !±_K/X~?= ~!

/'j j_WX?J /[~ 7j /= h 4'X= ±j*^X±j— j?/ ±j 7jK/= ' ¥3 —5 j;j?/=h

■ :—S 3 EOR X? ~ ±W j± /~ ±j7jK/ j;j?/= X? [ 'XK' /'j 7j /= — XJ' / ?~/ >j K~— %j/j°

~?J X/^W X?_° K~?/_X?jW X? /'j K_~±X— j/j±h 4'j ♦xa K_ ~ ±X— j/j± '_W _ Wj% /'

~ ! < rhcx~h

■ 00<$$ l us k j 1 iK z ['j±j *<$$ X= /'j X?;_±X_? / — _== ~ ! /' j /[~ j_WX?J 7j /= h

x !/j± _ K^ /= _ ±j _%%XjW * /'j±j [j±j nhr 4QV _?W mhu 4QV j;j?/= ±j— _X? X?J !~±

/' j N~[ — _==N _? W N;j±° ~[ — _==N /±XJJj±=* ±j=%jK/X;j°h x !^?K/X~? ~! /'j !~±—

S H q » —HE S » j * = ®TE Tphm'

[ _= ^=jW /~ !X/ /' j W X7j / X?;_±X_?/ —_== =% j K /±^ — X? /'j ±_?Jj ut d S * d nss

k j 1 iK ah 4 'j !X/ * ^ _ X/° [_= Q j m mrn !~± mau WjJ±jj= ~ ! !±jjW~— h 4'j !X/ *^_X/°

[_= X— %±~;jW =XJ?X!XK_?/° * b E f bphc !~± msb WjJ±jj= ~! !±jjW~— TWh~h!h'* [ 'j? /'j

±_? J j ps d S $ $ = mss k j 2 iK E [_= j]K^WjW !±~— /'j !X/ T=jj B XJ^ ±j phm_'h 6 'j? /'j

pp


respecti\·ely .. .\. jet algorithm using a cone size of 0.8 was applied to all events passing

the Level 2 trigger. and the jets in each event were ordered according to decreasing

Er.

The following offiine requirements were applied to events passing the Level 2

trigger:

• -200 mm< :: <200 mm \vhere :: is the longitudinal event vertex position. The

event vertex wa:; determined by the TOF detector.

• /co.s01j < 0.6 where 01,'2 an-' the polar angles of jet l and 2.

• E{ < 20 Ge\· where E:J. is the Er of the third jet. This requirement rejects

events with rnon• than 2 jets.

• f}m < 807c or felm < 803/t. where fe\J are thP electromagnetic f'IH~rgy fractions of

the leading two jets. This requirement rejects Z -+ ec e\·cnts.

• J,,1,~; > 20'fr in order to reject events in which the jets might not be rnmµletely

longitudinally contained in the calorimeter. The C ...\2 calorimeter had a depth

of"' 6.-5,\0 .

• m 11 > -10 Ge\"/ c'2 where m JJ is the invariant mass of the two leading jets.

After all cuts are applied, there were 3.6 -106 and 1.4 -106 events remaining for

the ·'low mass·· and ·'very low mass" triggers. respectively . ...\ function of the form

-a -3-m --y-m1 m ·e ·e (7.1)

was used to fit the dijet invariant mass spectrum m the range -18 < mJJ < 300

GeV/c2. The fit quality was x2 = 163 for 124 degrees of freedom. The fit quality

\Vas improved significantly, x2 = 97.5 for 109 degrees of freedom (d.o.f.), ,vhen the

range 70 < mjj < 100 GeV/c2 was excluded from the fit (see Figure 7.la.). \Vhen the

77

=%jK/±^— [_= !X/ [X/' /'j >_K9J±~^?W !^?K/X~? Tphm' _?W _ =XJ?_ !^?K/X~? K~?=X=/X?J

~! /[~ k _^==X_? W X=/±X>^ /X~?= [X/' /' j f —_==* /'j — _== ±j=~^/X~? _?W /'j =XJ?_

=X\j l _= !±jj %_±_— j/j±=* /'j? Q j ¥ X W !~± mam Wh~h!h 4 'j =XJ?_ K~?=X=/jW ~! crmt 7

mnnu j;j?/= [ X/' _ = /_ /X= /XK_ =XJ?X!XK_?Kj ~ ! uha qB 4'j >_K9J±~^?WE=^>/±_K/jW =XJ?_

X= ='~[? X? BXJ^±j phm> _~?J [X/' /' j ~;j±_ =XJ?_ !X/ _? W /'j K~?/±X>^/X~?= !±~—

/'j f _?W ' =j%_±_/j°h

nQ£ FOOOEOO

E_ nrss\

C GEOO

~ E0OO0£_

FEO ( smss?X77 Tkj1'

mssZQmas VO

BXJ^±j =CF- d,k ’p~*c> fB ' ¥3 $— N1 ’kk* (D muEC d,k =XJ?_ ’,^W* y^*’p’■’ ^" eVF0KFGG1

j;j?/=h

phn g , B , _/_

4'j W X7j / K±~== =jK/X~? X= ;j±° _±Jj _ / ~[ W X7j / —_==j=h x / /'j j?W ~! 0^? vg*

'_ ! ~! /'j g 4 g [_= /^ ±?jW ~!! W^j /~ _ >±~9j? [X±jh ZX?Kj /±_K9X?J ±j_W~^/ /j?W=

/~ >j /'j %±~'X>X/X;j° =~[ !_K/~± X? /_ 9 X? J W _ /_ _ / 'XJ' ±_/j=* _?W =X?Kj K_~±X— j/j±

X?!~±— _/X~?* ?~ / /±_K9X?J* X= /'j K±^KX_ X? !~ ±— _/X~? !~± /' X= _?_°=X=* _ ~[ /'±j='~W

^?%±j=K_jW W X7j / /±XJJj± [_= XWj_ !~± /' X= ±^ ?? X?J %j±X~Wh

4'j ~[ /'±j='~W W X7j / /±XJJj± ^=jW X? /' X= _?_°=X= K~?=X=/jW ~! /'j !~~[X?Jh

x / /'j !X±=/ /±XJJj± j;j* _ / j_=/ ~?j g w - /~[ j± _?W _/ j_=/ ~?j gqx /~[j± TX?WjE

%j?Wj?/°' [ X/' U P 1 u k j1 [j±j ±j*^ X±jW h x / /'j =jK~?W /±XJJj± j;j* _ %±X— X/X;j

pt


spectrum was fit with the background function (7.1) and a signal function consisting

of two Gaussian distributions with the iv mass, the mass resolution and the signal

size N as free parameters, then x2 = 114 for 121 d.o.f. The signal consisted of 5618 ±

1334 events with a statistical significance of 4.2 a. The background-subtracted signal

is shown in Figure i. lb along with the overall signal fit and the contributions from

the iv and Z separately.

> ~ 4800

al N

~ 4400

I>

l .~ .... 600 ~ bl

' .... .... , > GI

~ t.000

.f 3600

' z ~ 3200

'"!... ~ 2800

'

\ ~ 1.00

j, ! zoo I ~ I I .a ' 0 Q I --

r ~ ~ -200 rL) • ~ ,. I

+1 f ~ i I _______________ ___._ __ ......_ _ ___. 0 '--'-------------..._-~

e .... 60 80 100 120 60 BO 100 120 140 mjj (GeVI mii (GeVI

Figure i. l: The signal W, Z ~ jet8 seen by C' ..\2. The signal shown consists of 5618±1334

events.

i.3 CDF Data

The dijet cross section is very large at 10\v dijet masses. At the end of Run IC,

half of the CTC was turned off due to a broken wire. Since tracking readout tends

to be the prohibitively slow factor in taking data at high rates, and since calorimeter

information, not tracking, is the crucial information for this analysis, a low threshold

unprescaled dijet trigger was ideal for this running period.

The low threshold dijet trigger used in this analysis consisted of the following.

At the first trigger level, at least one CEM tower and at least one CHA tower (inde

pendently) with Er > 4 GeV were required. At the second trigger level, a primitive

78

K ^ =/j ±X?J _ J~ ±X/'— [_= _%% XjW h x K ^ = /j ± ±j*^X±jW _ =jjW /~[ j± [ X/' U P 1 n kj1h

x _W 7_Kj? / /~[j±= [X/' "1 l m kj1 [ j±j X?K^WjW X? /'j K ^=/j±h 4[~ K j ? /±_ 7j /=

[ X/' U P 1 ma k j1 [j±j ±j*^ X±jW h x/ /' j /' X±W _?W !X?_ /±XJJj± j;j* _ — ~±j j]E

/j?=X;j K ^=/j±X?J _J~±X/'— [_= ^=jW _?W /' j )j;j a ±j*^ X±j— j? /= [j±j ±jE±j*^X±jW h

x /~ /_ ~ ! mhb % > *F [_= /_9j? [ X/' /' X= /±XJ J j±h 4'X= X= _ — ^K' _±Jj± W _ /_ =_— %j

/' _? /' j j? /X±j 0 ^? v zw4Gas =_— %j T" i% ±j = K _ j f Tm b hm ic s s '% > Em !~± 0 ^? vx _?W

Tt u hm im s s s '% > G !~± 0^? vy'h

phu ZXJ?_ w ]%jK /_ /X~?=

g , B '_= — j_=^±jW /'j % ±~W^K/X~? K±~== =jK/X~? ~ ! vB _?W ' >~=~?= /X— j= /'j

j% /~?XK > ±_?K' X?J ±_/X~=h x KK~±WX?J /~ DnsVh

X/ ■ o f #l —_{ m ahub 7 OCFE ?> Tpha'

q » o ° ' * 3 0 0 { m shanm 7 OCOFE ?>

_ / PO- É mtss kj1h 4'j j% /~? XK > ±_?K' X?J ±_/X~= ~ ! /'j ;jK/~± >~=~?= _ ±j [j

Wj /j ±— X?jW e

o Q b ES N _ { f mshrt „ shmaR Tphn'

o ° ' ES iU iN ' f nhnrct 7 shssanb.

4 '^=* /' j % ±~W^K/X~? K±~== =jK/X~?= !~± vB _ ? W ' >~=~?= _ / 6\1 fmtss k j1 _ ±j anhm

?> _?W VC0V ?>h ±j=%jK/X;j°h k X;j? /'j [ jE— j_=^±jW '_W ±~? XK >±_?K'X?J ±_ /X~ =

o ° Q b El■ $ — N 1 { m rphbr 7 shncbK Tphu'

o ' $ — N 1 { m rbhbm 7 shsrR*

/'j K±~== =jK/X~? /X— j= '_W±~?XK >±_?K' X?J ±_ /X~ = _±j

q » o ° Q b #l $ — N 1 { f mchtu „ mhmc?> Tphc'

q » o ° ' ¥6 $ — N 1 { f uht „ shnr?>h

pb


clustering algorithm was applied . .-\ cluster required a seed tower with ET > 3 Ge\· .

. -\ll adjacent towers with Er > 1 Ge\· were included in the cluster. Two central jets

with ET > 12 Ge\" were required. At the third and final trigger level, a more ex

tensive clustering algorithm was used and the Level 2 requirements were re-required .

. .\ total of 1.9 pb- 1 was taken with this trigger. This is a much larger data sample

than the entire Run I JET .20 sample (.C/prescale= (19.l/.500)pb- 1 for Run I.-\ and

(8-1.1/lOOO)pb- 1 for Run IB).

7.--l Signal Expectations

CDF has measured the production cross section of tr and Z bosons times the

leptonic branching ratios. According to [:30].

er· B(tl" ~ ev) = 2.--19 ± 0.12 nb (- ·>) '·-

at J; = 1800 Ge\·. The leptonic branching ratios of the vector bosons are well

determined:

B(H. ~ ev) = 10.68 ± 0.127c

B(Z--+ r--r) = 3.3658 ± o.0021St

(7.3)

Thus. the production cross sections for n· and Z bosons at ./s =1800 Ge\' are 23.1

nb and 6.86 nb. respectively. Given the well-measured hadronic branching ratios

B(H" -+ jets) = 67.96 ± 0.3.:io/c

B(Z--+ jets) = 69.91 ± 0.06%,

the cross section times hadronic branching ratios are

(J • B(tV--+ jets)= 15.8-1 ± l.l5nb

a· B(Z-+ jets) = -l.8 ± 0.36nb.

79

(7.-l)

(7.5)

6 X/' ?~ 9 X?jX?_/XK_ K^ /= _?W mhb % > Em h [j j]%jK/ nssbr„amtc vB j;j?/= _? W bmas„rtu

' j;j?/=h

4 ' j /±XJJj± ±j*^X±j= /' _ / /'j /[~ ' XJ'j=/ D " 7j /= >j Kj?/±_ 7j /= * Xhjh* ’/=vXa’ d mhmh

x=~* =X?Kj — _?° vB = _?W ' 1 %±~W^KjW X? •• K~X=X~?= _ / 6\1 f mtss k j1 _ ±j %±~W^KjW

_ / ±j= / ~ ± ?j_±° _ / ±j= /* [j ±j*^X±jW T~!!X?j' /' _ / K ~ = TM d Es hu T A' l mmn“' ['j±j X=

/'j _?J j >j/[jj? /' j /[~ j_WX?J 7j /= X? D $ » v? ~ ±W j± /~ — j_=^±j /'j j!!jK/= ~! /'j=j

/[~ 9 X?j— _/XK_ K^ /= * [j Jj?j±_/jW ms*sss vB _?W mshsss ' j;j? /= ^=X?J L2 4q vx h

6j !~±KjW /'j >~=~?= /~ WjK_° /~ /[~ *^_±9= _?W X— %~=jW /'j ±j*^ X±j— j? /=

■ XAiXhE♦ d B v

■ K~=dIl d Es hu

~? /' j Jj?j±_/jW ;_^j= ~! 0$]j _?W d!l T?~ Wj /jK /~ ± =X— ^_/X~? [_= ^=jW'h 6j !~^?W

/'j j!!XKXj?K° /~ >j mphmR !~± vB j;j?/= _?W vZ huR !~± ' j;j?/=h

Z X?Kj [j _±j X? /j ±j=/jW X? j;j?/= [ X/' ~?° /[~ 7j /= * [j _=~ ±j*^ X±j T~!!X?j' D $ =

)s k j1 h ['j±j D$* X= /' j /±_?=;j±=j j?j±J° ~! /' j 7j / [ X/' /'j /' X±W ' XJ'j=/ ±_[ T?~

7j / K~ ±±jK /X~?=' D€* 6j _==^— j /'X= ±j*^ X±j— j?/ X= X?Wj%j?Wj?/ ~ ! /'j ±j*^X±j— j?/=

~? d mEm _?W K~=d' d #shuh x KK~±WX?J /~ g , B A= — j_=^±j— j?/ DnmV* /'j K±~==

=jK/X~? !~± vBEL l m 7j /= ['j±j /'j 7j / '_= j?j±J° J ±j _ /j ± /'_? mc k j1 K~±±jK/jW UP

T < ms k j1 ^?K~±±jK/jW ~± ±_[ U P j X= a hr„ s hr ?>h 4 ' j j!!XKXj?K° ~ ! /'j K ^ / ~? DJ0

/'j? X= tu„ uR !~± vB = h xKK~±WX?J /~ DnaV* /'j K±~== =jK/X~? !~± ' EvE m 7j / X= mhab„sham

?>h 4 ' j j!!XKXj?K° !~± ' 1 ~ ! /'j K^/ ~? D$* /'j? X= rt7xhB

x ==^— X?J /'j ±j*^ X±j— j? /= ~? d mEm _? W K ~ = Tvl d #shu _±j X?Wj%j?Wj?/

~! /'j ±j*^ X±j— j?/ ~? D $ E* /'j? /'j j;j?/ =jjK/X~? j!!XKXj?KXj= !~± vB = _?W ' 1 _±j

muhu„shpR _?W mnhu„shbR * ±j=%jK/X;j°h x =^ — — _±° ~ ! j;j?/ =jjK/X~? j!!XKXj?KXj=

TXhjh* _KKj% /_?Kj=' X= JX;j? X? 4_>j phmh

8 =X?J /' j K~— >X?jW j!!XKXj?K° *^~ /jW X? /'j _=/ K~^— ? ~! 4 _> j phm* [j j]%jK/

_ /~ /_ ~ ! unnn„npt vB j;j?/= _?W maaa„man ' j;j?/= ['j? _ /' ±jj ±j*^X±j— j?/=

ts


\Vith no kinematical cuts and 1.9 pb-t. we expect 30096±2185 n· events and 9120±684

Z events.

The trigger requires that the two highest Er jets be central jets, i.e., i11t,21 < 1. 1.

Also, since many n·s and Zs produced in pp collisions at Js =1800 GeV are produced

at rest or nearly at rest. we required (offiine) that cos < -0.-1(\P > 113°) where is

the angle between the two leading jets in Er. In order to measure the effects of these

two kinematical cuts, wr generated 10.000 ir and 10.000 Z e\·ents using PYTHL.\.

\\"e forced the bosons to decay to two quarks and imposed the requirements

• ''lt.2! < 1.1

• cos < -0.-1

on the generated values of '/t.2 and (no detector simulation was us('(l). \\"e found

the efficiency to be 17'. l Yc for i r e\·ents and 1S.-1 <X. for Z events.

Since we a.re interested in events with only two jets. we also require (offline) E:} <

10 Ge\ .. where £} is the transverse energy of the jet with the third highest raw ( no

jet corrections) Er. \\·e assume this requirement is independent of the requirements

, on !TJt.21 < 1.1 and cos < -OA. According to CDF's measurement [31]. the cross

section for ir + ? 1 jets where the jet hce; energy greater than 15 GeV corrected Er

( "-' 10 Ge\. •mcorrecte<l or raw Er) is 2.6±0.6 nb. The efficiency of thP cue on EJ..

then is 8-l±-1% for trs . According to [32], the cross section for Z + 1 jet is 1.29±0.21

nb. The efficiency for Zs of the cut on E":J. then is ,3±5%.

Assuming the requirements on l'li,21 < 1.1 and cos < -0.-1 are independent

of the requirement on E:J., then the event selection efficiencies for irs and Zs are

l-!.-1...:....0. T7c and 13.-l±0.9%, respectively. .--\ summary of event selection efficiencies

(i.e., acceptances) is given in Table 7.1.

C'sing the combined efficiency quoted in the last column of Table 7.1, we expect

a total of 4333±378 n· events and 1222± 123 Z events when all three requirements

80

4_>j phme Z^— —_±° ~! j!!XKXj?KXj=h

9'ha’ ” X E X DJ0 e FO 3 ks g ~— >X?jW

K~=dB ” * O C1

^ F=CFey 01K1‘y F1C1KOC=I

C F0C1‘y =GKe‘y FGC1KOC‘‘y

T’ F=FhEm d m m h K~= »/l d #shuh D$* d ms k j1 ' _±j _%% XjW h 6j ~~9 !~± /'j /[~ =XJ?_=

_= _? j]Kj== ~! j;j?/=* X?K^WX?J >~ /' v4 _?W H j;j?/= T~cck„nbt j;j?/='* _>~;j /'j

=— ~~/' 3 g , WX7j/ >_K9J±~^?W h

phc g j?/±_ g _~ ±X— j/j± hzj/ g ~±±jK/X~?=

v? 0 ^? vh g , B j= /_> X=' jW _ ±~^ /X?j* 9?~[? _= z4gbk h /' _ / %j±!~±— jW N= /_? W _ ±W N

7j / K~ ±±jK/X~?=h 4 'j K~ ±±jK /X~?= X?K^WjW Tm' _ ±j_ /X;j K~±±jK/X~?h : 0—]■ ['XK' K~ ±±jK /jW

* !~± /'j + ±j=%~?=j ~ ! /' j K_~±X— j/j± ±j _ /X;j /~ /' j Kj? /±_ ±jJX~? Ta' _? _> =~ ^ /j

j?j±J° =K_j K~ ±±jK /X~? h : q9tB Tn' _? ^?Wj±° X?J j;j?/ K~±±jK/X~? < Z D ■ _?W Tu' _? ~^ /E

~!EK~?j K~±±jK /X~? h c O B 4 'j=j K~±±jK/X~?= [j±j _%% XjW _= !~~[=e

LP PNj m k $ qÎ{ » E0—]°I{ » :q91°I{ P < Z D ° I { * c O ° I { Tphr'

['j±j I X= /' j 7j / K~?j =X\jh x =^— — _±° ~ ! /'j=j K~ ±±jK /X~?= X= JX;j? X? DapV* 4 ' j % _ ±E

/XK^ _± K~ ±±jK /X~ ? [j _ ±j K~?Kj±?jW [ X/' X= i _Uu* /'j _> =~ ^ /j j?j±J° =K_j K~±±jK/X~? h

4 'j — j/' ~ W ^=jW /~ j = /_> X=' /'X= K~ ±±jK /X~? X? 0 ^? v X= Wj=K±X>jW X? DnnVh v? =' ~ ±/*

/'j 3 B) K_ ~ ±X— j /j ± = X— ^ _ /X~ ? [_= N /^?jWN /~ ±j% ±~W^Kj Kj±/_X? K_ ~ ±X— j/j± =XJ?_

W X=/± X> ^ /X~ ? = !±~— /j = /> j _ — _?W <* 1 <NR W _ /_ DnuV* z j /= [j±j Jj?j±_ /jW [ X/' Z w 4 L 0 4

tm


Table 7.1: Summary of efficiencies.

1,11.21 < 1.1 Ef < 10 Ge\' I Combined

cos < -0.-1 I I

iv 17.lo/c 8-1±-1% 1-1.4±0. 7%

z 18.-19c -·3..i...:-9;: I• ~;J C I 13.4±0.93/c '

(1'71.21 < 1.1. cos 1I> < -0.-1. Ef < 10 Ge\") are applied. \\"e look for the two signals

as an excess of en•nts. including both n· and Z events (5.5.SG±398 events). abo\·e the

smooth QCD tlijPt background.

, .:J Central Calorimeter .Jet Corrections

In Run I. CDF established a routine, known as .JTC9G. that performed ··standard ..

jet corrections. The corrections included (1) a relative correction. fre1- which corrected

, for the '7 response of the calorimeter relative to the central region (2) an absolute

energy scale correction. labs· (3) an underlying event correction CE, and (-1) an out

of-cone correction. OC. These corrections were appli"cl as follows:

P,(R) = Pfau.·(R) · lre1(R) · labs(R) + CE(R) - OC(R) (i.6)

where R is the jet cone size . .-\. summary of these corrections is given in (2,]. The par

ticular correction we are concerned with is labs, the absolute energy scale correction.

The method used to establish this correction in Run I is described in [33]. In short,

the QFL calorimeter simulation was "tuned'' to reproduce certain calorimeter signal

distributions from testbeam and in situ. data [3-1] . .Jets were generated with SETPRT

81

T^=X?J vZ x zw 4 ±~^ /X?j=' _? W =j?/ /' ±~ ^ J ' 3 B ) h 4 ' j _> =~ ^ /j 7j / K~±±jK/X~? [_=

[ 'j±j % L Y sN X= /' j /±^ j Jj?j±_ /jW % _ ±/~ ? j?j±J° _? W k • ] X= /'j j= /X— _ /j T!±~—

3 B) ' ~! [ '_/ /'j — j_=^±jW j?j±J° [~^W '_;j >jj? '_W /' j 7j / _K /^_ ° Wj%~=X/jW

X/= j?j±J° X? /' j K_ ~ ±X— j/j±h 4 'j _>=~ ^ /j K~ ±±jK /X~? X= JX;j? _= _ !^?K/X~? ~! /'j

K~?j =X\j I >jK_^=j L Y _±/sI [_= Wj!X?jW _= /'j =^— ~ ! _ W _^ J ' /j ± %_±/XKj= T!±~— /'j

~±XJ X?_ % _ ±/~ ? ' /' _ / !j X?/~ _ 7j / ~ ! K~?j =X\j IB 4 ' X= %±~Kj== [_= ±j%j_/jW !~± rs

>X?= !±~— sErss k j 1 iK k • ] B B~± j_K' >X?h /' j — j_? ~! /' j L % X±6? W X=/± X> ^ /X~ ? [_=

% ~ //jW _= _ !^?K/X~? ~ ! /'j — j_? ~! /'j L % W X= /± X> ^ /X~ ? h 4 'j ±j=^/X?J K^±;j [_=

%_±_— j/±X\jW * _? W /'j %_ ±_— j/j ±X\_ /X~ ? [_= ^=jW X? hz4gbkh

v? /'j=j =X— ^ _ /X~ ? = * /'j '_W±~?XK j?j±J° =K_j [_= =j / _KK~±WX?J /~ [ '_/ X= ±jE

!j±±jW /~ _= N- j/'~W vN X? DnrVh q~[j;j±* X? DncV _?W DnrVh _? ~ /' j ± — j/'~W ~! =j //X?J

/'j j?j±J° =K_j ~! /'j '_W±~?XK =jK/X~? ~ ! /'j K_ ~ ±X— j/j ±= TN- j/'~W vvvN' [_= %±jE

=j?/jW h 6j '_;j ^=jW /' X= ?j[ j?j±J° =K_j /~ j= /_> X=' _ ?j[ _>=~ ^ /j 7j / j?j±J°

=K_j K~±±jK /X~? h qj±j* [j Wj=K±X>j /'j % ±~KjW^±j [j ^=jW /~ j=/_>X=' /' X= ?j[ K~±E

h ±jK/X~? h Q ^ ± — j/' ~ W X= >_=jW ~? /'j K_ ~ ±X— j/j ± =XJ?_= ±jK~±WjW !~± %_±/XKj= [X/'

[j Wj /j ±— X? jW !~^± ;jK/~±= T!±~— 0 ^? vy — X? X— ^— > X_= W _ /_ ' h 6j ^=jW /'j=j =XJE

?_= /~ ±jK~ ? =/±^ K / /' j =XJ?_= ~ ! = X— ^_/jW 7j /= h g _ X> ±_ /X~ ? K~?=/_? /= _±j K'~=j? =~

_= /~ _;~XW > X_=j= >_=jW ~? = /_ ± /X? J %~ X? /= ~ ! ='~[ j±=* /' j ^?Wj±° X?J %'X~=~%'° ~!

_ 7j / X= /±j _ /j W _= _ K~jK/X~? ~! %_±/XKj=* j_K' [ X/' ;_±° X?J j?j±J° _?W K'_±Jjh B~±

_ 7j / ~ ! j?j±J° D <—N [j ^=jW /'j !±_J— j? /_ /X~? !^?K/X~?

['j±j y ° C { X= /' j % ±~ > _> XX/° /' _ / _ 7j / !±_J— j? / [X ±jKjX;j _ !±_K/X~? C ~! /'j

• % _ ± /~ ?

:q91°I{ Tphp'

- j/'~W vvvh

z j /= [j±j J j? j ±_ /jW _KK~±W X?J /~ /' j — j/' ~ W Wj=K±X>jW X? DnrVh 6 X/' /' X= — j/'~Wh

8 S C ' 9 S c * . > ' S > * ; ' } L ; Tpht'

ta


( using IS.-\JET routines) and sent through QFL. The absolute jet correction was

(7.,)

where P,¥artan is the true generated parton energy and Pft is the estimate (from

QFL) of what the measured energy would have been had the jet actually deposited

its energy in the calorimeter. The absolute correction is given as a function of the

cone size R because Plarton was defined as the sum of all daughter particles (from the

original parton) that fell into a jet of cone size R. This procc·ss was repeated for 60

bins from 0-600 Ge\"fc Pt. For each bin. the mean of the Pf;irtun distribution was

plotted as a function of the mean of the Pt distribution. The resulting curw was

parametrized. and the parameterization was used in .JTC!JG.

In these simulations. the hadronic energy scale was set according to what IS re

ferred to as ··~Iethod I" in [.36]. However, in [3.5] and [36]. another mt>thod of setting

the energy scale of thl' hadronic section of the calorimeters ( ·'~fethod III") was pre

Sf!nted. \\'e have used this new energy scale to establish a new absolute jet energy

scale correction. Here. we describe the procedure we used to establish this new cor-

, rection. Our method is based on the calorimeter signals recorded for particles \Vith

well determined four vPctors (from Run IB minimum bias data). \\'e used these sig

nab tu reconstruct the signals of simulated jets. Calibration constams are chosen so

as to avoid biases based on starting points of showers, the underlying philosophy of

~fethod III.

Jets were generated according to the method described in [36]. \Vith this method,

a jet is treated as a collection of particles, each with varying energy and charge. For

a jet of energy £jet we used the fragmentation function

D(z) = (n + 1)(1 - =t / z (,.8)

\Vhere D(z) IS the probability that a jet fragment will receive a fraction .. of the

82

% _ ±/~ X±= — ~ — j? /^ — _?W _ X= _ %_±_— j/j± T[j ^=jW q m r' /~ ±_?W~— ° =jjK/ * 7j /

!±_J— j?/= [ X/' j?j±J° D N m D<—N » C =^K' /' _ / w 7j/ f TBZ<'Z< 4'j K'_±Jj ~! j_K'

!±_J— j?/ [ _= K'~=j? ±_?W~— ° =~ /' _ / nnbK ~ ! /' j /X— j X/ X= _ ?j^ /±_ %X~? _? W rpR

~! /' j /X— j _ K'_±JjW %X~?h

] ms°G ] ms

asss B mv Z-!Aj_X

gbbbrAshaaUp rsss ±E I ♦abbbrp®V

v 8jKU shmsrc ’mpcs -

I n6Z ghU4nZcsss

n; A m b ; = ahacpu ■

mcssmacs

w X X Xv v v % f sEm usss

\ e

”~h

msss m N nsss- i

pcs asss

?mq *

css 5 emacs 'r msss t n R

s c p r f 9 s U© 1

s ahc c phc ms s ahc c phc ms

cssss

■ussss

k¥ k*k]~D

mssss

s

± T /hAq±h-- 4 m -j~E nhcU_Kp u s ns B?):5

) 7T % f Ea=u :]* u u

V �

-5XE/ Yt

— r r s r r 9 r :

phc ms

] ms

mssss E74

tsss p(

rsss ?

4666 T tq mI

EOOO — s

ss

,cJ k*k]~D

nnUpac -j~£ shEcrnhA♦ oU1Z a nzrs o

• 9 F*E

phc ms

k¥ k*k]~D ,cJ k*k]~D

B XJ^±j phae g j? /±_ K_~±X—j/j± =XJ?_ WX=/±X>^/X~?= ~>/_X?jW ^=X?J X=~_/jW /±_K9= !±~— 0^? vy —X?X—^— >X_= W_ /_ h ZXJ?_ WX=/±X>^/X~?= _±j ='~[? =j%_±_/j° !~± /'j jjK/±~—_J?j/XK _?W '_W±~?XK =jK/X~?= !~± /±_K9= [X/' —~—j?/_ X? /'j sEm k j1 iK ±_?Jj _?W mEa kj1iK ±_?Jjh Zjj /j]/ !~± Wj/_X=h

B XJ^±j= pha* phn* _ ? W phu ='~[ K_~±X— j/j± =XJ?_ W X= /± X> ^ /X~ ? = ~> /_ X?jW !±~— X=~E

_ /jW '_W ±~?= X? 0 ^? vy — X?X— ^— >X_= W _ /_ h ZXJ?_ W X= /± X> ^ /X~ ? = !±~— /'j jjK/±~E

tn


parton's momentum and o is a parameter (we used a = 6) to randomly select n jet

fragments with energy £ 1 = £jet · : such that Ejet = L::~ £,. The charge of each

fragment was chosen randomly so that 33% of the time it is a neutral pion and 67%

of the time a charged pion.

1500

1250 1000 750 500 250

0

0

., -_..,

., -_..,

i:'.:r,tr,~

; Ue-:.,

i ~"s

p = 0-1

5

em energy

1 [.,tr . ..,

I \Ice ..

~M5

7.5

p = 1-2

5 7.5

em energy

T :999€7 C.22.c.7 C.-4T::i~

IO

.5J4,"2~

11)

6000

5000

-1000

3000

2000

1000

~ ·1 r: : I :-1 C :1 i- I

E:~ ,-1 I ,1 I

~ I

~ ! ...; , ~ I ;

: I'.._ 0

X 10

10000

!1000

6000

2000

0

0

0

, ---~

' £.,t,,e-, I I Uec.-, I ~\IS

p =0-1

5 7.5

had energy

€.'.'!tn•~ Vee ..

! ~vs

p = 1-2

., -_.::, 5

had energy

7.5

f:)999677 o. ,ces

1 ::;;.25?4 ·

10

B• 725 ~._jti.:Jl ; :: :,.!02 ;

10

Figure i.2: Central calorimeter signal distributions obtained using isolated tracks from Run IB minimum bias data. Signal distributions are shown separately for the electromagnetic and hadronic sections for tracks with momenta in the 0-1 GeV/c range and 1-2 GeV/c range. See text for details.

Figures 7.2, 7.3, and iA show calorimeter signal distributions obtained from iso

lated hadrons in Run IB minimum bias data. Signal distributions from the electro-

83

— _J?j/XK _?W '_W ±~ ? XK =jK/X~?= _ ±j ='~[? =j% _±_ /j ° !~± '_W ±~ ? = [ X/' ;_±° X?J —~E

— j? /_ T— j_=^±jW >° /'j /±_K9 X?J =°=/j— 'h 4 'j !~~[X?J ±j*^X±j— j?/= [j±j _%%XjW

/~ /±_K9= X? ~ ±W j± /~ — _9j /'j % ~ /= h

■ ’W~X d shc K— h ’g* < C_ N€ Q = c K— h • N 3 shn k j1 iK h 4 'j=j ±j*^ X±j— j?/= [j±j

_%%XjW X? ~ ±W j± /~ K'~~=j ' XJ'E*^_X/° /±_K9=h 6 X/' /'j=j ±j*^X±j— j?/=* [j

K_? >j ±j_=~?_> ° =^±j /' _ / /' j ±jK~?=/±^K/jW /±_K9 K~±±j=%~?W= /~ _ K'_±JjW

%_±/XKjh

■ Yj—I'_W d Yss kj1 h 4 ' X= ±j*^X±j— j?/ j X— X?_ /jW /±_K9= !~± ['XK' /' j j?j±J°

X? /'j /_ ±J j / T /' j K_ ~ ±X— j/j± /~[j± /'j /±_K9 j ] /±_% ~ _ /jW /~' j— ~± '_W±~?XK

/~[j± [_= J ±j_ /j ± /'_? ubb kj1h

■ 4±_K9= [j±j ±j*^X±jW /~ ' X/ /' j K_~±X— j/j± X? /'j j /_ ±_?Jjh P,qP d shgr =X?Kj [j

_±j ~?° X? /j ±j= /jW X? /±_K9= ['XK' 'X/ /'j g j? /±_ K_~±X— j/j±h

■ 6j ±j*^X±jW /' _ / ?~ ~ /'j± /±_K9 ' X/ /'j K_ ~ ±X— j/j± X? /'j au /~[j±= =^ ±±~^?W X?J

/'j /_±Jj / /~[ j± X? ~±Wj± /~ =jjK/ X=~_/jW /±_K9=h

B~± j_K' K'_±JjW 7j / !±_J— j?/* _ ? j jK/±~— _J?j/XK —NS _?W '_W±~? XK —>q% =XJ?_ [_=

±_?W~— ° %^jW !±~— /'j=j W X= /± X> ^ /X~ ? = _KK~±WX?J /~ /'j 7j / !±_J— j? /A= j?j±J°h B~±

j]_— %j* !~± _ mht k j1 K'_±JjW 7 j / !±_J— j?/* _? j jK /±~— _J?j/XK _? W '_W±~?XK =XJ?_

[_= ±_?W~— ° %^ jW !±~— /'j W X= /± X> ^ /X~ ? = [ X/' — j_=^±jW ' _W ±~? — ~ — j ? /_ • f m E a

w 5 Q Z \ 5 B 4'j 7j / !±_J— j? / [_= /' j? _ //± X> ^ /j W _? jjK /±~— _J?j/XK _? W '_W±~?XK =XJ?_

~ ! D'S f Tm ht im hc 'jj— _?W D g q% f Tm ht im hc 'jx_/d* ±j=%jK/X;j°h g ~— %_±jW /~ K'_±JjW

7j / !±_J— j?/=* /'j K_~ ±X— j/j± j?j±J° — j_=^±j— j?/ ~! ?j^ /±_ !±_J— j?/= °HFZ1 _?W

= ♦=' X= *^ X/j %±jKX=jh 6j /'j±j!~±j ^=j /'j j?j±J° ~ ! ? j^ /±_ !±_J— j? /= j]_K/° _= /'j°

K~— j !±~— /'j !±_J— j? /_ /X~? !^?K/X~? h

4 ' X= %±~Kj== [ _= ±j%j_/jW !~± j_K' ~ ! /'j * 7j / !±_J— j?/= /' _ / — _Wj ^% /' j 7j / ~!

j?j±J° "47j/h 4 'j j?j±J° /'j K_ ~ ±X— j /j ± [~^W '_;j ±jK~?=/±^K /jW !~± /'X= 7j / * D 0—5£q

tu


magnetic and hadronic sections are shO\vn separately for hadrons with varying mo

menta (measured by the tracking system). The following requirements were applied

to tracks in order to make the plots.

• Idol $ 0.5 cm, J.:0 - zz:txl ~ 5 cm. Pt 2: 0.3 Ge\"/c. These requirements were

applied in order to choose high-quality tracks. \Vith these requirements. we

can be reasonably sure that the reconstructed track corresponds to a charged

particle.

• £;:1:<l < -199 Ge\·. This requirement eliminated tracks for which the energy

in the target ( the calorimeter tower the track extrapolated to) em or hadronic

tower was greater than -199 Ge\".

• Tracks were required to hit the calorimeter in the eta rnngP. irJ/ $ O.GG since we

are only interested in tracks which hit the Central calorimeter.

• \\"e required that no other track hit the calorimeter in tlw 2-1 towers surrounding

the target tower in order to select isolated tracks.

For each charged jet fragment, an electromagnetic eem and hadronic ehad signal was

randomly pulled from these distributions according to the jet fragment ·s energy. For

example. for a 1.8 Ge\" charged jet fragment, an electromagnetic and hadronic signal

was randomly pulled from the distributions with measured hadron momenta p = 1-2

Ge\'/c. The jet fragment was then attributed an electromagnetic and hadronic signal

of E:'n = (l.8/l.5)eem and £fad = (1.8/l.5)ehaa. respectively. Compared to charged

jet fragments, the calorimeter energy measurement of neutral fragments (11°·s and

,·'s) is quite precise. \Ve therefore use the energy of neutral fragments exactly as they

come from the fragmentation function.

This process \Vas repeated for each of the n jet fragments that made up the jet of

energy £jet· The energy the calorimeter would have reconstructed for this jet, Erecon

84

■,k* p’ ’p¥•>D

w - s? f ° T ■ S D J q % ■ T < E b '

[ 'j±j xe X= /'j !_K/~± ^=jW /~ ±jK_X>±_/j /'j ' _W ±~ ? XK j?j±J° =K_j _KK~±WX?J /~

N- j/' ~ W v vv h£ 4 'j 7j/ = XJ ? _ W X=/±X>^ /X~?= /' _ / ±j=^ / !±~— /'j=j =X— ^ _ /X~ ? = _±j

='~[ ? X? B XJ^±j phch x % ~ / ~ ! /'j 7j / ±j=%~?=j T$ — N f ° D E g £q{ \ D$—N{ ■&C’ w7j/ !~±

- j /' ~ W vh $— NU B _?W - j/'~W vvvh X= ='~[ ? X? B XJ^ ±j phrh

4 ' j ?j[ _>=~ ^ /j 7j / j? j±J° K~±±jK/X~? X= /'j?

D ? m D Z? ■ ] \ $ 5 N S Tphms'

[ 'j±j D*? m D —0* S v » D >q% o^^ v f shtmh

phr v?X/X_ =j_±K' % ±~KjW^±j

B XJ^ ±j php ='~[= /'j 7j / E 7j / X?;_±X_?/ — _== =% j K /±^ — X? /'j j?j±J° ±_?Jj !±~—

nsEmss k j C i K N h B~± — _==j= J ±j_ /j± /' _? cs k j 1 iK ah /' j W X= /± X> ^ /X~ ? X=h X? !X±=/

_% % ±~ ] X— _/X~ ? * ±j_=~?_>° j]%~?j?/X_h 6j =/^W XjW '~[ [j /'j W X= /± X> ^ /X~ ? X= WjE

Y =K±X>jW >° _? j]%~?j?/X_ !^?K/X~? >° Wj/j ±— X? X?J /' j * ^ _ X/° ~! _? j]% ~ ? j? /X_ !X/

X?;~;X?J !~^± %~ X? /= _ / ~[ — _== Txi$h x i Y h xi?S_E _? W am %~X?/= ±_?J X?J !±~—

xi$ S an k j1 iKa /~ xi$ S ua w — T \ 0 jB 4 'j C a ;_^j= ~ ! /'j=j !X/= T!~± an WjJ±jj= ~!

!±jjW~— ' _±j % ~ //jW _= _ !^ ? K /X~ ? ~! , * X? B XJ^±j phth

4 ' j ~?=j/ ~! /'j /±XJJj± X?j!!XKXj?K° — _?X!j=/= X/=j ! _= _ =^WWj? X?K±j_=j X? /'j

* Ca ;_^j !~± , * d cc k j 1 iK ah 4 ' j X?K±j_=j X? Q j ;_^j= X? /'j ±_?Jj rs d xi$ d ts

k j C i Ka K~±±j_ /j= [ X/' _? j]Kj== ~! j;j?/= /' _ / X= ~>=j±;jW X? /'X= — _== ±_?Jj ['j?

!X/= [ X/' xi$ f cr *cp *ct T[ 'XK' '_;j _ ;j±° J~~W C a' _ ±j K~?=XWj±jWh 4 ' j j]Kj==

_>~;j /' j j]%~?j? /X_ >_K9J±~^?W X= ='~[? X? B XJ^±j p hb_ !~± /'j !X/ [ X/' xi? f cp

k j C i K ah 4 ' j±j =jj— = /~ >j _ %j_9 /' _ / K~? /_ X?= _ /~ /_ ~! < t *sss j;j?/=* Kj?/j±jW

_ ±~ ^ ? W S $ $ f rp k j1 iKah

tc


then is simply

£recun =(~£em-+- £had. k) Jet L , · , i=l

(7.9)

where k is the factor used to recalibrate the harlronic energy scale according to

'·.\[ethod III.'' The jet signal distributions that result from these simulations are

shown in Figure 7.5. _..\ plot of the jet response (jet = ( Efee;00) /£jet) us £jet for

.\Iethod L jeti. and '.\[ethod IIL jetm is shown in Figure 7.6.

The new absolute jet energy correction is then

£corr = £raw . l /J. Ct Jet Jet Ill (i.10)

when~ Ef~~w = Ew1 + k · Ehad and k = 0.81.

,.6 Initial search procedure

Figun' 7. 7 shows the jet-jet invariant mass spectrum m the energy range from

30-100 Ge\"fc'2. For masses greater than 50 Ge\"/c?. the distribution is. in first

approximation. reasonably exponential. \\"e studied how well the distribution is de-

, scribed by an exponential function by determining the quality of an exponential fit

involving four points at low mass (.\/11 • .\!11 ..-L • .\ln+·i . . \/11 ~3) and 21 points ranging from

JI n + 23 Ge\·/ r to .\/11 + -l 2 Ge\·/ r2 . The \ '2 values of these fits ( for 2:3 degrees of

freedom) are plotted as a function of Aln in Figure 7.8.

The onset of the trigger inefficiency manifests itself as a sudden increase in the

x2 value for .\In < 5-5 Ge\"/c'2. The increase in x2 values in the range 60 < J/11 < 80

Ge\"/c:1- correlates with an excess of events that is observed in this mass range when

fits with .\In = 56, 57, -58 ( which have a very good x2 ) are considered. The excess

above the exponential background is shown in Figure ,.9a for the fit with J/11 = 57

Ge\"/ c2. There seems to be a peak that contains a total of "" 8, 000 events, centered

around mJ1 = 67 Ge\'/ c'!..

85

6 'j? /'j 7j / K~ ±±jK /X~?= W j=K ±X> jW X? ZjK/X~? phc [j±j _% % XjW _ ? W /' j _>~;j

_?_ ° =X= [_= ±j%j_ /jW * /' j j]Kj== ~ ! j; j? /= _>~;j /' j j]%~?j?/X_ >_K9J±~^?W ='X!/jW

/~ ' XJ'j± — _== ;_^j= _? W X?K±j_=jW /~ < ma*sss j;j?/=h 4'j ±j=^ /= _ ±j ='~[ ? X?

B XJ ^ ±j phb>h 4 'j j]Kj== [_= !X/ [ X/' /' j =^— ~ ! /[ ~ k _^==X_? W X= /± X> ^ /X~ ? = * [ X/'

j]Kjj? / ±j=^/=h 4 'j WX!!j±j?Kj >j /[ jj? /'j /[~ — j_?= _?W /'j ±_ /X~ ~ ! /' j [ XW/'=

~ ! /' j /[~ J_^==X_?= [j±j !X]jW X? /' j !X/ /~ msht w — T \ 5 j _?W mh ±j=%jK/X;j°h x

~ /' j ± % _ ±_— j/j±= X? /' j !X/ [j±j j!/ !±jj h 4'j W ~ //j W K^±;j= X? B XJ ^ ±j p hb> ±j%±j=j?/

/' j /[~ k _^==X_?=h _? W /'j =~XW K ^ ±; j X= /'j =^— ~ ! /' j /[~h 4 ' j Q j ;_^j ~! /'X=

!X/ X= mbha !~± aa WjJ±jj= ~ ! !±jjW~—h 4 ' j /[~ k _^ ==X_? = _±j Kj? /j ±jW _ ±~ ^ ? W pths

_ ? W ttht k j2 iKah ±j=%jK/X;j°h x KK~ ±W X?J /~ /'j !X/* /' j %j_9 K~?=X=/= ~ ! bsss „ mcss

' _W ±~ ? XK_ ° WjK_°X?J 6 = _?W ncss „ mcss ' Z =h 4 ' X= %^/= /' j % ±~ W ^ K/X~ ? ±_/X~

q ° • • #l ' ' ■ y ' *Y $ 5 N 1 { \ q • • #► v4 ' ■ o ° Q T #l $ — N 1 { /~ _ ;_^j =~— j[ 'j±j >j/[jj?

sha _ ? W shch 4 'X= ±_ /X~ X=h X? !X±=/ _% % ±~ ] X— _/X~ ? * X?Wj%j?Wj? / ~! X? = /±^ — j ? /_ j!!jK/=

=^K' _= /±XJJj± j!!XKXj?KXj=* Wj /jK /~ ± _KKj% /_?Kj * —N5BB v/ X=h [ X/'X? j] % j ±X— j? /_ j±±~±=*

X? _J ±jj— j? / [ X/' /'j j]%jK/jW ;_^j ~ ! shnsp Tw * ^ _ /X~ ? phr'h

php g ~±±jK /X?J !~ ± /±XJJj± X?j!!XKXj?KXj=

v? g , B ?~/j umbm* /'j _^ /'~ ±= — j_=^ ±jW /'j /± XJ J j ± j!!XKXj?K° ~ ! /' j , vzw 4 hm a

/± XJ J j ± ^=X?J =X?Jj 7j / /±XJJj± j!!XKXj?KXj=h 4 'jX± ±j=^ /= =^JJj=/jW /' _ / /' j /±XJJj±

[_= ? ~ / !^° j!!XKXj?/ >j~[ _ WX7j/ — _ == ;_^j ~! < mns k j2 iKah 6j '_;j ^=jW _?

_ /j ±? _ /X; j — j/'~W /~ — j_=^±j /'j /± XJ J j ± j!!XKXj?K°h 4 ' j =/j%= X?;~;jW X? j] /±_K /X? J

_ /± XJ J j ± j!!XKXj?K° K^±;j _? W _ =XJ?_ !±~— /'j ±_[ W _ /_ _±j _= !~~[=e

■ v? /' j ±jJX~? ~ ! /'j W X7j / — _== = % j K /±^ — [ 'j±j ~? ° >_K9J±~^?W j;j?/= TW X7j/=

!±~— 3 g , %±~Kj==j=' _±j j ] % jK /jW /~ >j !~^?W* [j !X/ /'j W X7j / — _== =%jK/±^—

[ X/' /'j !^?K/X~?_ !~±— ^=jW >° 8x a* ?_— j°

— 3j E n— j E p—& h Tphmm'

0V


\Vhen the jet corrections described in Section 7.5 were applied and the above

analysis was repeated, the excess of events above the exponential background shifted

to higher mass values and increased to "' 12,000 events. The results are shown in

Figure 7.9b. The excess was fit 1,vith the sum of two Gaussian distributions. with

excellent results. The difference between the two means and the ratio of the widths

of the two gaussians were fixed in the fit to 10.8 Ge\"jc2 and 1. respectively .. .\II

other parameters in the fit were left free. The dotted curves in Figure 7.9b represent

the two Gaussians. and the solid curve is the sum of the two. The '(:! value of this

fit is 19.2 for 22 degrees of freedom. The two Gaussians are centered around ,8.0

and 88.8 Ge\"jc2 • respecti\·ely .. \ccording to the fit. the peak consists of 9000 ± 1500

hadronically decaying U "'s and 3-SOO ± 1500 z·s. This puts the production ratio

CJ(pp -t Z) · B(Z ~ jct~)/a(pp ~ti·)· B(tr ~ jet:i) to a value somewhere between

0.2 and 0.5. This ratio is. in first approximation. independrnt of instrumental effects

such as trigger efficiencies. detector acceptance. etc .. It is. within experimental errors.

in agreement with the expected valuf' of 0.30, (Equation 7.6).

i. 7 Correcting for trigger inefficiencies

In CDF note -!191, the authors measured the trigger efficiency of the DI.JET _12

trigger using single jet trigger efficiencies. Their results suggested that the trigger

was not fully efficient below a dijet mass value of"' 130 Ge\"jc2. \re have used an

alternative method to measure the trigger efficiency. The steps involved in extracting

a trigger efficiency curve and a signal from the raw data are as follows:

• In the region of the dijet mass spectrum where only background events ( dijets

from QCD processes) are expected to be found, we fit the dijet mass spectrum

with the functional form used by L" • ..\2, namely

o -3-m -"'{·rnZ m e e . (7.11)

86

['j±j S ° m *<$${ X= /'j W X7j / X?;_±X_?/ — _== _?W _ * tB _? W = _±j !±jj %_±_— j/j±= h

4'X= !X/ [ _= %j±!~±— jW X? /' j ±jJX~? S * f mac E nss k j 2 iK E _?W X= ='~[? X?

BXJ^±j phms !~± /'j ±_[ W X7j / — _== =% j K /±^ — TXhjh* ?~ 7j / K~±±jK/X~?='h

■ 4 'j !X/ /~ /' j >_K9J±~^?W ±jJX~? [_= j ] /±_% ~ _ /jW /~ W X7j / —_== ;_^j= >j~[

/'j = /_ ± /X? J %~X?/ ~! /' j >_K9J±~^?W !X/h Xhjhh >j~[ 00<$$ f mac k j 2 iK ah v? /'j

±jJX~? _>~;j _?W >j~[ /' j j]%jK/jW = XJ?_ ±jJX~? S ®E f rs E ts k j 2 iK E !~±

/'j ±_[ W X7j / — _== =%jK/±^— ' /'j ~ ±XJ X?_ W _ /_ [_= W X; XWjW >° /'j j] /±_% ~ _ /X~ ?

~! /'j >_K9J±~^?W !X/ X? ~ ±W j± /~ !X?W _ /±XJ J j ± j!!XKXj?K° K^±;jh Z^K' _ K^±;j X=

='~[? X? B XJ^±j phmmh

■ 4'j /±XJJj± j!!XKXj?K° K^±;j [_= !X/ ~? /' j j!/ _?W ±XJ' / =XWj ~! /' j j]%jK/jW

=XJ?_ ±jJX~? [ X/' /[~ WX!!j±j?/ !^?K/X~?=h

w!!—77 m •< *0 T•3 /_? ' il •T] E % *' ' T < mE'

w!!—o7 f °•< S _ ± K / _ ? •3°€ * •t{{•B< Tphmn'

['j±j •~;j _?W >j~[ /'j j]%jK/jW = XJ?_ ±jJX~? [j±j ^=jW /~ !X?W /'j /±XJJj±

j!!XKXj?K° X? /'j j]%jK/jW =XJ?_ ±jJX~?h

■ 6j WX;XWjW /' j ~±XJX?_ W _ /_ X? /'j =XJ?_ ±jJX~? >° _ !X/ /~ /'j /±XJJj± j!!XKXj?K°

K^±;j /~ !X?W /'j WX7j/ — _== =%jK/±^— * K~ ±±jK /jW !~± /±XJJj± X?j!!XKXj?KXj=h 4'X=

±j=^/= X? _ N/±XJJj± K~±±jK/jWN W X7j / — _== =%jK/±^— h

■ BX?_°* [j =^ > /±_K /jW /'j ~±XJ X?_ >_K9J ±~^?W !X/ Tj] /±_% ~ _ /jW /~ ;_^j= ~!

W X7j / — _== X? /'j j]%jK/jW =XJ?_ ±jJX~?' !±~— /'j /±XJJj± K~±±jK/jW W X7j / —_==

=%jK/±^— h B XJ^ ±j phma ='~[= _ /°%XK_ ±j=^ / ~ ! /'X= % ±~KjW^±j !~± /' j ±_[ W _ /_

T?~ 7j / j?j±J° K~±±jK/X~?='h 6 j K~^?/jW /' j ?^— >j± ~! j;j?/= X? /' j j]%jK/jW

=XJ?_ ±jJX~?h

tp


where m( = m1i) is the dijet invariant mass an<l a. 3. and ~· are free parameters.

This fit was performed in the region m 11 = 125 - 300 GeV/2- and is shown in

Figure 7.10 for the raw dijet mass spectrum (i.e., no jet corrections).

• The fit to the background region was extrapolated to dijet mass values below

the starting point of the background fit. i.e .. below rn11 = 125 Ge\)r?. In the

region above and below the expected signal region ( m JJ = 60 - 80 Ge\"/ r? for

the raw <lijet mass spectrum) the original data was di\·ided by the extrapolation

of the background tit in order to find a triggN efficiency curw. Such a curw is

shown in Figure 7.11.

• The trigger f'fficiency curve was fit on the left and right sid1• of the expected

signal region with two different functions.

(7.1~)

( 7. I:3)

where Pt· fJ.:! .• P:1, p.1 are free parameters in the fit. These fits to the trigger etfi.

ciency above and below the expected signal region were used to find the trigger

effiriency in the expected signal region.

• \\"e divided the original data in the signal region by a fit to the trigger efficiency

curve to find the dijet mass spectrum. corrected for trigger inefficiencies. This

results in a ·'trigger corrected'' dijec mass spectrum.

• Finally, we subtracted the original background fit ( extrapolated to values of

dijet mass in the expected signal region) from the trigger corrected dijet mass

spectrum. Figure 7.12 shows a typical result of this procedure for the raw data

(no jet energy corrections). \Ve counted the number of events in the expected

signal region.

87

4 'j? [j ±j% j_ /jW /' X= j?/X±j %±~KjW^±j !~± /' j W X7j / — _== =% jK /±^ — X? ['XK' 7j /

j?j±JXj= [j±j ~> /_ X? jW _= Wj=K±X>jW X? ZjK/X~? phc TN- j/' ~ W vvv =% jK /±^ — N'h x /°% XK_

±j=^ / ~! /' X= % ±~KjW^±j X= ='~[? X? B XJ^±j phmnh

pht 0 j=^/=

phthm ZXJ?_ L ±~ % j±/Xj =

4_>j= phah phnh phuh phch phr X=/ /' j ±j=^/= ~ ! — _?° WX!!j±j?/ !X/=h v? /'j=j !X/=h

■ WX!!j±j?/ !X/ — j/'~W= T C ah )X9jX'~~W' [j±j ^=jW /~ !X/ /' j >_K9J±~^?W ±jJX~?

■ W X!!j±j?/ ?^— >j±= ~! %~X?/= ~? /'j j!/ _? W ±XJ' / =XWj= ~! /'j j]%jK/jW =XJ?_

±jJX~? [j±j ^=jW /~ !X/ /'j /±XJJj± j!!XKXj?K° K^±;j=

■ W X!!j±j?/ !^?K/X~?_ !~±—= T_ ±j /_ ? _?W /_?' ' [j±j ^=jW /~ !X/ /' j /±XJJj± j!!XKXj?K°

K^±;j

0 j=^ /= _±j ='~[ ? !~± /'j ±_[ W X7j / — _== =% j K /±^ — T4_>j pha' _?W /'j WX7j/ — _==

=% jK /±^ — X? ['XK' 7j / j?j±JXj= [j±j K~±±jK/jW [ X/' /'j % ±~KjW^±j Wj=K±X>jW X? ZjKE

/X~? phc T4 _>j= phn* phuh phch phr'h w ?/±Xj= X=/jW X? /' j /_> j= K~±±j=%~?W /~ !X/= ~ !

/'j /±XJJj± j!!XKXj?K° K^±;j X? ['XK' /'j ±jW^KjW Q j ;_^j= [j±j j== /' _? mhmh

B~± /'j ±_[ W X7j / — _== =%jK/±^— h un !X/= '_W ±jW^KjW € j ;_^j= j== /'_? mhmh 4 ' j

— j_? ;_^j ~ ! /'j ?^— >j± ~! j;j?/= X? /'j =XJ?_ ±jJ X~? !~± /'j=j un !X/= X= nrrt j;j?/=

_? W q 0S1 f mabp j;j?/=h B~± /'j N- j/'~W vvv = % j K /±^ — i♦ mma !X/= ±j=^ /jW X? ±jW^KjW

Mj ;_^j= j== /' _ ? mhmh 4 'j — j_? ;_^j ~! /'j ? ^ — > j± ~ ! =XJ?_ j;j?/= !~± /'j=j mma

!X/= X= btpn j;j?/=h 4 ' X= K~±±j=%~?W= /~ _ =XJ?_ /~ >_K9J±~^?W ±_ /X~ ~ ! < mirb [ 'j?

X? /j J ±_ /X? J /' j j] /±_% ~ _ /X~ ? ~! /'j >_K9J±~^?W !X/ /~ /'j W X7j / — _== =%jK/±^— !±~—

00<$$ f pa # bt w — T \ 5 jB B~± /'j mma !X/= /~ /'j N- j/' ~ W vvv =% jK/±^ — *N d±±—= f nbcs

j;j?/=h 6j X? /j ±% ±j / /'j q 0S1 _= /' j =°=/j— _/XK j ±±~ ± ~? /'j ?^— >j± ~! v4 _?W '

j;j?/= ~>=j±;jW W^j /~ /' j ^?Kj±/_ X? /° ~ ! /'j /± XJ J j ± j!!XKXj?K°h

00


Then we repeated this entire procedure for the dijet mass spectrum in which jet

energies were obtained as described in Section T.5 ( ··'.\Iethod III spectrum"') .. -\ typical

result of this procedure is shown in Figure 7.13.

T.8 Results

7.8.1 Signal Properties

Tables 7.2. T.3. T.-1. T.-5. i.6 list the results of many different fits. In these fits.

• different fit methods ( x·!. Likelihood) were usecl to fit thr background region

• different numbers of points on the left and right sides of the expected signal

region were used to fit the trigger efficiency curves

• different functional forms (arctan and tanh) were usPd to fit the trigger efficiency

curve

Results are shown for the ra.w <lijet mass spectrum (Table T.2) and the dijet mass

spectrum in which jet energies were corrected with the procedure described in Sec

tion T.5 (Tables 7.3, i.-L 7.5. 7.6). Entries listed in the tables correspond to fits of

the trigger efficiency curve in which the reduced x2 values were less than 1.1.

For the raw dijet mass spectrum, -13 fits had reduced x2 values less than 1.1. The

mean value of the number of events in the signal region for these -13 fits is 3668 events

and r7r111:; = 1297 events. For the ··.\Iethod III spectrum," 112 fits resulted in reduced

x2 values less than 1.1. The mean value of the number of signal events for these 112

fits is 987:3 events. This corresponds to a signal to background ratio of,..__ 1/60 when

integrating the extrapolation of the background fit to the dijet mass spectrum from

m1j = 72 - 98 GeV/c?. For the 112 fits to the ''J.fethod III spectrum," arms= 3950

events. \Ve interpret the O"rms as the systematic error on the number of ir and Z

events observed due to the uncertainty of the trigger efficiency.

88

4_>j phae B X/= /~ /'j /±XJJj± j!!XKXj?K° K^±;j Wj±X;jW !±~— _ Q j _?W X9jX'~~W !X/ /~ /'j >_K9J±~^?W ±jJX~? 00<$$ f mac # nss k j1 iKa' ~! /'j ±_[ WX7j/ —_== =%jK/±^— T?~ 7j / j?j±J° K~±±jK/X~?='h B^?K/X~?= X?;~;X?J _±K/_? _?W /_?' T=jj w*^_/X~?= phmnh phma' _±j ^=jW /~ !X/ /'j /±XJJj± j!!XKXj?K° K^±;j* _?W WX!!j±j?/ ?^—>j±= ~! %~X?/= ~? /'j j!/ _?W ±XJ'/ =XWj= ~! /'j =XJ?_ ±jJX~? _±j X?K^WjW X? /'j !X/ T/~ /'j /±XJJj± j!!XKXj?K° K^±;j'h x j?/±Xj= X? /'j /_>j K~±±j=%~?W /~ !X/= T/~ /'j /±XJJj± j!!XKXj?K° K^±;j' ['XK' '_W ±jW^KjW € j ;_^j= j== /'_? h h

y _ K 9 J ±~ ^ ? W > X / X ± X? J j ± ' / !^ ? K /X~ ? =K % / hm X j X / =K % / = ± XJ ' / = XJ ? _ m w ± ±~ ± ~ ? = XJ ? _ X9 j X' ~ ~ W _ /_ ? s E b c u c m hu c m N X9 j X' ~ ~ W _ /_ ? t t r c a m hn u rnn hbcm X9 j X' ~ ~ W _ /_ ? ms b utmu hrm rnm srm/ X9 j X' ~ ~ W _ /_ ? ms u utbm br rnm mpbX9 j X' ~ ~ W _ /_ ? ms p uppu c r n s hb b cX9 j X' ~ ~ W _ /_ ? ms !/ ubnm au m rnm aur X9 j X' ~ ~ W /_ ? ' b b z c p t un X9 j X' ~ ~ W /_ ? ' mc as mpumhbt r a c ht t b X9 j X' ~ ~ W /_ ? ' ms as a u m p htb r a p satX9 j X' ~ ~ W /_ ? ' ■n as hmnsc aa r a t cmc X9 j X' ~ ~ W /_ ? ' t as n m b u pp r a t hnnm X9 j X' ~ ~ W /_ ? ' p as aarc c r a r hp b bX9 j X' ~ ~ W /_ ? ' r as a u p n cn r a p mncX9 j X' ~ ~ W /_ ? ' c as aabr sa r a r bmuX9 j X' ~ ~ W /_ ? ' u as auum sa r ap mpbX 9 j ' ' ~ ~ W /_ ? ' b u s p p ra r a b na b ’/X9 j X' ~ ~ W /_ ? ' mc t mraa su ra c hr b t 7X 9 j X' ~ ~ W /_ ? ' mc !/ v t ss rc r a c hb U b m X9 j X' ~ ~ W /_ ? ' e~ u a b a c u c ra p bsb X

1U _ /_ ? b b r c s t ! /7 puU u v v5U _ /_ ? t rr b m hs n pun rbm]| _ /_ ? mc as nbnm bb pun brc

_ /_ ? ms as n s z r ap pua unb;U _ /_ ? p as mpbs 1' pus unc

m_ /_ ? as mrbu pn pu s hpcp

m _ /_ ? u as a a m n sa p u m n u pX _ /_ ? mc c n t p b pt pun baa

]| _ /_ ? mhc b nnsa pun ssn] U _ /_ ? mc t nhcash X!/ pu n nur5| _ /_ ? mhc p n n n p c!/ pmn scp5| _ /_ ? mc r n r n a um pun car] o _ /_ ? ms b mumn br puu ttr

_ /_ ? ms u u a u n rm pu m cp5| _ /_ ? ms p u n n a su puu pu c] o /_ ? ' ©m b u s c s tn puu nac5| /_ ? ' ms as n s n n mp pua rmt5N /_ ? ' b as n r at hpm pun crp5| /_ ? ' t as n r u a ht pun cbu5| /_ ? ' p as n r n c hp r punErub5U /_ ? ' r as nuum pn pu n acm5| /_ ? ' c as u u n t hn c puc srt5| /_ ? ' u as ur p c uc p u c hm t c5| /_ ? ' b c uunu an puu ♦lst

x= _ K'jK9 ~ ! ~^± — j /' ~ W * [j ±j% j_ /jW /'j % ±~KjW^ ±j Wj=K±X>jW _>~;j [ X/' /'j

±_[ WX7j/ — _== =% jK /±^ — > ^ / ^=jW _ W X!!j±j? / j]%jK/jW =XJ?_ ±jJX~?h S * f b s E m m s

w — T \ 5 jB [ 'j? !X//X?J /' j /±XJJj± j!!XKXj?K° K^±;j* Xhjh* [j ~~9jW !~± _ =XJ?_ X? _

W X7j / — _== ±jJ X~? ['j±j [j [~^W ?~/ j] % jK / /~ !X?W ~?jh 4 'j ±j=^ /= _±j ='~[? X?

4_>j= php _ ? W phth B X!/°E=j;j? !X/= /~ /' j /±XJJj± j!!XKXj?K° K^±;j ±j=^ /jW X? ±jW^KjW

M j ;_^j= j== /' _ ? mhmh 4 ' j — j_? ;_^j ~ ! /' j ?^— >j± ~ ! =XJ?_ j;j?/= X= un j;j?/= _? W

Y±—X f E pu j;j? /=h 4 '^=* X? _ ±jJX~? [ 'j±j ?~ =XJ?_ X= j]%jK/jW * _ ±j=^/ K~?=X=/j? /

[ X/' \j±~ = XJ ? _ j;j?/= X= !~^?Wh

tb


Table 7.2: Fits to the trigger efficiency curve derived from a x2 and likelihood fit to the background region (m11 = 125-300 GeV / 2) of the raw dijet ma.ss spectrum (no jet energy corrections). Functions involving arcta.n and tanh (see Equations i.13. i.12) are used to fit the trigger efficiency curve. and different numbers of points on the left and right sides of the signal region are included in the fit ( to the trigger efficiency curve). All entries in the table correspond to fits (to the trigger efficiency curve) which had reduced x2 values less than 1.1.

D4t:Xirrounc1 t-1t iril(Ker ht .unction :.: ot., tett # Pl.i n1e:nt ::-,,~na.1 r.rror on s1,cn~u 1u.eHhood £tan ,, ,, .,,~ 1.4~ t).).,.~tjt}

likelihood at.u, s ~ 65:?l.34 633.951 likelihood a.tan 10 'l 4~ 1-1.61 631.061 likelihood atan 10 ~ 459191! 631 l 79 likelihood ua.n 10 4774.5 630.995 hkrhhood a.tan 10 6 .i~:11.2-1 631 .H6 l1k.rhhooo t.Anh

I ,,

'J J.>', •. , ~,., u,. likelihood tanh t5 20 l 741.9~ 6:?5.~SIJ likelihood tanh 10 20 2-ll 7 .~1J ri:!'7 O:.?.~ ~t ke l t h.uu<l t~nh •} '.!O .\)05.:!".! ,;-~~ 515 !iic.ehhood tanh ~ 20 .lt 94 77 6:?.1.JJt likel1hood ta.nh 20 2:?65, 626. 799 hkelihooJ ta.nh 6 20 '.!-1-:"l ".3 IP" . ' l.l~ lik•lihoud ta.uh 5 10 .?:!9-'! O'.! 6:!6.~.n., !ikPlihooi.l ~anh t !O :.?•l-&1.0:! 6:.?7 179 likPhhooJ

I tanh 9 5 4077 ti:! 6:!9 3:!!J

I likrlihoud ta.nh 15 <\ 16:?:.?.tH i ti:.?.5.ti9,"4 likPllhood ta.nh 1, .; l.<\O1) 65 I O:.Z."i.cJ-"49 ltkrlihooJ ~4rth I !ll " :!9:.?~ .I,') ri:!7 'JQlj I

\: : a.tan 9 ~ 6.50-" tiJ

I 7-1.• Ht

\: a.ta.n ,; ; tiri'Jl.0J 74~ 691 .... a.t•n l~ ~D J9.ll <J<J I 7U.%,; l

a.t.:ln 10 :!O JOJri.:!7 74:!.43'} \,

\; atan 7 w 17'JtJ 'i') 7~0 H.5

l, 4lclll 5 -.!O ts•H 7:1 7-tG.7'.';7

\: .1tan ~

I 20 :.?:.?lJ O:! 74!.JH

\" 4t.ln l; 5 .l.~7'.) 7.~ 7-tJ. '.J".!:.?

\ : ~ta.n 1:; I ') UO:! 7~J.0ll.l

\.: a.~J.n 15 1 I J.";:.!0.1'"1 "7-IJ .l-lfi I i \: AtJ.0 !.5 7 I J:U7 .)ti 71.1017

I ... - ,1.tar, 15 6 JfiJ:! -ll

I ;-.,J 5".!6

< ,U..in :o ~ l~IJ % 7H ->-"Ii \: 4ld0 10 • i:!-Util 7-11 '}';" .- a.t ... n tu 7 ~J.1:!.04 7H 7~5

-..: ta.nh 'l 1 40!".10.~J 7~-1.J.!5

\: ta.nh 10 !0 3U3J 17 7'4:! 61~

\: tanh <J :.?0 J6:.?-"L71 743.567

\: t4nh ; :.?O 364:!.; 743 S<J~

< tanh 7 :!O 3635.76 743.64'.l

< tanh 6 :!O JHI 73 7-IJ.:.?o;l

< tAnh 5 !U HJ,1 . .!5 745 Oh."

-..: td.nh 4 w --107).-15 :-4.'j_ ,~.5 ,· tanh 'l I H:H.2.1 7H•>tl-"

.-\s a check of our method. we repeated the procedure described above with the

raw dijet mass spectrum but used a different expected signal region. m11 = 90 - 110

GeV/c2 • when fitting the trigger efficiency curve, i.e., we looked for a signal in a

dijet mass region where we would not expect to find one. The results are shmvn in

Tables 7. 7 and 7.8. Fifty-seven fits to the trigger efficiency curve resulted in reduced

y 2 values less than I. I. The mean value of the number of signal events is 43 events and

arms = 27 4 events. Thus. in a region where no signal is expected. a result consistent

with zero signal events is found.

89

4 _>j phne B X/= /~ /'j /±XJJj± j!!XKXj?K° K^±;j Wj±X;jW !±~— _ X9jX'~~W !X/ /~ /'j >_K9J±~^?W ±jJX~? °00<$$ ¥ mac E nss k j1 iKa' ~! /'j WX7j/ —_== =%jK/±^— X? ['XK' 7j/ j?j±JXj= [j±j K~±±jK/jW ^=X?J /'j —j/'~W Wj=K±X>jW X? ZjK/X~? phch x !^?K/X~? X?;~;X?J _±K /_? T=jj w*^_/X~? phmn' X= ^=jW /~ !X/ /'j /±XJJj± j!!XKXj?K° K^±;j* _?W WX!!j±j?/ ?^—>j±= ~! %~X?/= ~? /'j j!/ _?W ±XJ'/ =XWj= ~! /'j =XJ?_ ±jJX~? _±j X?K^WjW X? /'j !X/ T/~ /'j /±XJJj± j!!XKXj?K° K^±;j'h x j?/±Xj= X? /'j /_>j K~±±j=%~?W /~ !X/= T/~ /'j /±XJJj± j!!XKXj?K° K^±;j' ['XK' '_W ±jW^KjW € j ;_^j= j== /'_? mhmh

y _ K 9 J ±~ ^ ? W ' X / v ± ^ j j ± ' / T ^ ? K / X~ ? F % /b Xj / / U" Q /= ± XJ ' / v = X J ? _ v!U s ~ n n 8

X9 j X' ~ ~ W _ /_ ? , & A4 a4 4 n p mshnnh X ± X9 j X' ~ ~ W _ /_ ? t u mac-th m mstn t X9 j X' ~ ~ W _ /_ ? c m r c s su mspa bX9 j X' ~ ~ W _ /_ ? zQ a c s b um mspnhsu X9 j X' ~ ~ W _ /_ ? U zQ a s m s s+ mspahun X9 j X' ~ ~ W _ /_ ? as m b - bnr mspa c X9 j X' ~ ~ W _ /_ ? as a u p m h mm mspn uu X9 j X' ~ ~ W _ / _ ? as c r r m c r mspb uc X9 j X' ~ ~ W _ /_ ? as trz- su msUu mn X9 j X' ~ ~ W _ /_ ? ■X mc r r c p ar mspb -X9 j X' ~ ~ W _ /_ ? mc r a s p sr mspthb X9 j X' ~ ~ W _ /_ ? [ L r m a p aa mspn = m X9 j X' ~ ~ W _ /_ ? mc r a c s ca mspb mc X9 j X' ~ ~ W _ /_ ? mc x- mc r n ms-n un X9 j X' ~ ~ W _ / _ ? v mc 8 s- p m mstp paX9 j X' ~ ~ W _ /_ ? b Q m m b r a hr msup pp X9 j X' ~ ~ W _ /_ ? u ms m m c p p v mstp aX9 j X' ~ ~ W _ /_ ? ms m m b m p hu 0641 ! . X9 j X' ~ ~ W _ /_ ? r ms v mpum n mstp cu X9 j X' ~ ~ W _ /_ ? c ms m a c r a mstb uu X9 j X' ~ ~ W _ /_ ? u ms m u m c s p msba ar X9 j X' ~ ~ W _ /_ ? ©+ ©+ m a u r r b ms nt cn X9 j X' ~ ~ W _ /_ ? b p manuu v mstn u X9 j X' ~ ~ W _ /_ ? b r m a n b b c mstt mcX9 j X' ~ ~ W _ /_ ? l h b m a m c b a msnhu u m X9 j X' ~ ~ W _ /_ ? c v u m n b s s n msbm ur X9 j X' ~ ~ W _ / _ ? Y T p m a s U u ms t u pc X9 j X' ~ ~ W _ /_ ? I U h u s p r r p msua rr

phtha g±~== =jK/X~? _?W K~— %_±X=~? [X/' Z /_ ? W _ ±W - ~Wj

4 ' j ?^— >j± ~! j;j?/= !~^?W [ X/' /'j N- j/'~W vvv =% j K /±^ — N '_= >jj? K~?;j±/jW

/~ _ K±~== =jK/X~? >° K~±±jK/X?J !~± j;j?/ =jjK/X~? j!!XKXj?KXj= TXhjhh _KKj%/_?Kj='h v?

ZjK/X~? phu* /'j j!!XKXj?KXj= ~ ! 9 X?j— _/XK K^ /= _ ±j W X=K^==jW X? W j /_ Xh 4'j _=/ K~^— ?

~ ! 4 _> j phm X=/= /'j K~— >X?jW j!!XKXj?KXj= ~ ! _ 9 X? j— _/XK K ^ /= * muhuR _?W mnhuR

!~± v4 _? W H j;j?/= ±j=%jK/X;j°h 8=X?J /'j j]jK/jW K±~== =jKX~? ±_/X~ ~! - = _?W

'1 ■ Td ±T- A'iK±TX±* ' { _?W K±TH 'iK±T- A H ''* _ K~— >X?jW - AH j!!XKXj?K° ~! muha„mhaR h

4 ' j K~ ±±jK /jW K±~== =jK/X~? X= q » o ° Q b ■ ' El $ — N 1 { f nrhr „ muhrT=°=' „ u ha T= /_ /' ?>*

_%% ±~ ] X— _/j ° mhm =hW h _±Jj± /' _ ? /'j Z /_ ? W _ ±W - ~Wj % ±jW XK /X~ ? ~! K± ■ o ° f B ' #l©

$ — N 1 { f as ?> Tw * ^ _ /X~ ? phr'h

8xa _=~ *^ ~ /jW _ K±~== =jK/X~? _±Jj± /' _ ? /'j Z /_ ? W _ ±W - ~Wj %±jWXK/X~? DabV*

bs


Table 7.3: Fits to the trigger efficiency curve derived from a likelihood fit to the background region (m11 = 125 - 300 GeV/c2) of the dijet mass spectrum in which jet energies were corrected using the method described in Section i.5. A function involving arctan (see Equation i.13) is used to fit the trigger efficiency curve. and different numbers of points on the left and right sides of the signal region are included in the fit ( to the trigger efficiency curve). All entries in the table correspond to fits (to the trigger efficiency curve) which had reduced x2 values less than 1.1.

n ~· t unCtlOO I C1h00 a.tan -- ' ~i, ... '

likelihood •ta.n ,; ,; l!5:,~. i 10.-;~ ~ likelihood a.tAn \ 5 16,5~.114 !07:!.9 likelihood .. ta.n ~ :?U 2509.41 l07J.04 tLkelihood a.ta.n -I ·.?o 2010 Q,; 107"1.U likelihood ata.n :?O 19t<9.~6 lOn I likelihood a.ta.n ,; 20 ~471.-ll l07J H likelihood a.ta.n I ~a 5tHH-~6 l079 ·" likehhood •ta.n ~ 10 ~6JI! 04 l0~4 ::i hliu!lihood a.tan ., l5 6~57 ~~ 107'1J ~ hlc.elihood ata.n l5 ri:!07.0~ l07R.~ likelihood .1.t,1.n . ' 'il!7.J:.! 107~ -,1 hkelihood .1.ta.n ti l.5 t>'..?50.5:.! l079 15 like It hood •t&.n I l5 -~ 15 63 lOdJ 'iJ likelihood ata.n I l5 ll0,<7' l lOS7 :·! lik!i!:hhood At An <j lO t t-Jti:?.6 10~7 77 likrlihood ata.n ; w l l5-:'7' I l0~7 2 hke-lihood a.ta.n lO l l9l -:'.4 ltl~7' t)~ likelihood 4ta.n ~ lO l l 7<l ~ l0e!7 H itkrlihood ,ltd.ti ~ lO 1:.!56:? l01i9H likelihood a.t4n ~ lll l-U10.7' 109:!.:.!ti hk~iihood a.td.n ., - I:.!-ltiti '.) 10~, ... 'i.~ !1ltt!lihooJ a.ta.n ') 7 l:!34-1 l lU;,, -I !1k1!l1hood 4ta.n ., 6 l:.!J~9 '; lOMI.~ likl!lihoud at.i.n 9 L!l'>~-~ lU.'i.< < I likrl1hooJ 4td.U '\ lJ~M}0 . .1 llJ'.ll .iti !dc.rl1hoo<l .1.ta.n l".!0""'-( lllt'll'\ :"'i l1kf"lihood ,1,t,u, ,; '1()7t-i ri7' lil"''! ~iti

7.8.2 Cross section and comparison with Stanrlard .\Iodel

The number of events found with the ··.\Iethod III spectrum .. has been converted

to a cross section by correcting for event selection efficiencies (i.e .. acceptances). In

Section 7.4, the efficiencies of kinematic cuts are discussed in detail. The last column

of Table ,.1 lists the combined efficiencies of all kinematic cuts, 1-l.-!% and 13.4%

for Ir and Z events respectively. C'sing the exected cross secion ratio of IVs and

Zs, (a(H.)/a(Ir, Z) and a(Z)/a(lV, Z)), a combined Ir, Z efficiency of l-l.2±1.2%.

The corrected cross section is a· B(n·, Z---+ jets) = 36.6 ± l-l.6(sys) ±-l.2(stat) nb,

approximately 1.1 s.d. larger than the Standard :\lodel prediction of a· B(H', Z ---+

jets) = 20 nb (Equation ,.6).

CA.2 also quoted a cross section larger than the Standard .\Iodel prediction (29].

90

4_>j phue B X/= /~ /'j /±XJJj± j!!XKXj?K° K^±;j Wj±X;jW !±~— _ X9jX'~~W !X/ /~ /'j >_K9EJ±~^?W ±jJX~? TS * f mac # nss kj1iKa' ~ ! /'j WX7j/ —_== =%jK/±^— X? ['XK' 7j/ j?j±JXj= [j±j K~±±jK/jW ^=X?J /'j — j/'~W Wj=K±X>jW X? ZjK/X~? phch x !^?K/X~? X?;~;X?J /_?' T=jj w*^_/X~? phma' X= ^=jW /~ !X/ /'j /±XJJj± j!!XKXj?K° K^±;j* _?W WX!!j±j?/ ?^—>j±= ~! %~X?/= ~? /'j j!/ _?W ±XJ'/ =XWj= ~! /'j =XJ?_ ±jJX~? _±j X?K^WjW X? /'j !X/ T/~ /'j /±XJJj± j!!XKXj?K° K^±;j'h x j?/±Xj= X? /'j /_>j K~±±j=%~?W /~ !X/= T/~ /'j /±XJJj± j!!XKXj?K° K^±;j' ['XK' '_W ±jW^KjW Q j ;_^j= j== /'_? mhmh

m > _ K 9 J ±~ ^ ? W ' X/ / ± X J J j ± ' / !^ ? K /X~ ? F % / = j ! / =K ±l/= ± XJ ' / m = XJ ? _ !K ±±~ ± ~ ? = XJ ? _ X9 j X' ~ ~ W / _ ? ? b v X ! ub n ( - phcz X9 j X' ~ ~ W / _ ? ' n n mactr mstthnnX9 j X' ~ ~ W / _ ? ' asus bn mspnhpuX9 j X' ~ ~ W / _ ? ' ° as u pcp su msprhpbX9 j X' ~ ~ W / _ ? ' n as u t br hau mspphmaX9 j X' ~ ~ W / _ ? ' as u u uu hsc msprhcrX9 j X' ~ ~ W / _ ? ' as c r bc han mspthcaX9 j X' ~ ~ W / _ ? ' c as s b n s hp u mstc rbX9 j X' ~ ~ W / _ ? ' u as mapsb c msbs nmX9 j X' ~ ~ W / _ ? ' b mc pccb c mstm spX9 j X' ~ ~ W / _ ? ' mc p u c u hs c msns bbX9 j X' ~ ~ W / _ ? ' mc purc am msnm sm X9 j X' ~ ~ W / _ ? ' r mc pnrn ru mstmhpnX9 j X' ~ ~ W /_ ? ' mc mmurs r mstp ba X9 j X' ~ ~ W / _ ? ' u mc mnnru z e~ ~ X bc X9 j X' ~ ~ W / _ ? ' b ms mmrup n msnp nrX9 j X' ~ ~ W / _ ? ' &< /~ mmnbm p mstr bbX9 j X' ~ ~ W / _ ? ' ms mmcauha mstp mu 7 X9 j X' ~ ~ W / _ ? ' r ms v mrnn n mstp ntX9 j X' ~ ~ W / _ ? ' c ms mntbphp msbmhcnX9 j X' ~ ~ W / _ ? ' u ms mcpbshn msbuhppX9 j X' ~ ~ W / _ ? ' b t mactn mstmhtnX9 j X' ~ ~ W / _ ? ' b p mauap b mstt cp X9 j X' ~ ~ W / _ ? ' Z $ r v mbbp u mstp tnX9 j X' ~ ~ W / _ ? ' c b mnucn v msbs nnX9 j X' ~ ~ W / _ ? ' c m munsc msba n XX9 j X' ~ ~ W / _ ? ' c p mntnp a msbmhucX9 j X' ~ ~ W / _ ? ' c r bmrr an msnu u c

4 'j ±_ /X~

~ G GGGGGGGGGGGGGGGG =r* o ° Q b B ' #l ++ 'GGGGGGGGGGGGGGGGG

U ■ o ° ]b El ■ O " c « ——{ ■ Q J J

X= j]%jK/jW /~ >j ^?X/° X? /' j Z /_? W _±W - ~Wjh 4'j ;_^j= ~! /'j ±_/X~= ~ ! /'j %_±/X_

WjK_° [ XW /'= X? /~ *^_±9= _? W j%/~?= _ ±j

± ° f g + + {± [ Y 4 r Aas T * A s'± ' El ++{ G am m

± T H #ljj'

8xa *^~ /jW _ ;_^j I f mhpm „ shuch 6 j !X?W I m mhpu 7 shpah

bm


Table 7.-l: Fits to the trigger efficiency curve derived from a likelihood fit to the background region (mn = 125 - 300 GeV /c-) of the dijet mass spectrum in which jet energies were corrected using the method described in Section 7.5. A function involving tanh (see Equation 7.12) is used to fit the trigger efficiency curve. and different numbers of points on the left and right sides of the signal region are included in the fit (to the trigger efficiency curve). All entries in the table correspond to fits (to the trigger efficiency curve) which had reduced x2 values less than 1.1.

n er t .ur.ct1on # ts •. t I ... Ou tann

likelihood ta.nh ,1 3 likelihood :anh 5 5 likelihood tMth 'I ~o likelihood ta.nh ,. w !ik~lihood tanh :!O likelihood ta.nh ti !O Sti~5 . .!~ lakelihood tanh 5 !0 9930. 7-1 1,k~lihood t.i.nh • w l 2709 5 l1ltel1hood ta.nh '.J 15 7559 ) likelihood t.-nh 8 15 7-154.0~ likelihood t4llh 15 7'-105.:!I likehhood ta.oh ,; 15 7.'!r!J 6~ liic.rlihood ta.nh 5 1.5 IH60 6 likelihood ta.r.h • l.5 lJ,l6. l likelihood ta.nh 9 :0 : 16-17 !l t1kelihood ta.nh ~ 10 l lJ!ll 7 likelihood tanh Ill 111:.?·L! likellhuud ta.nh .; lO l ltiJJ .-I lakelihuod tanh .5 10 l3d9i. 7 likehhood tanh -I 10 15790.J likelihood tanh ') ; l:!.'it"l" likelihuorl ta.nh '.I l:.!-127 '.) likehholld tanh 'J 6 I t')q7 -I !t.C.elihnod t.1.nh 5 ,, [.j..,1$,ol l iik~!ihood tanh 5 ; !-1~05 likelihood tanh '; tJaJ7 2 l1kel1hu,ht t.,nh ,; 9166 :!~

The ratio

R = a· B(tr, Z-+ q,j)

B( rr· ) r(W-.qijJ B(Z ) a. •• -+ ev . qn·-.ev) +a. -+ ee .

rror on ,1 , . .J ...

1081!.~J 1073.7-1 lll76.7'l 1077.l! 1076.Sri 107~.5'! 10115 M !090 Jl IU~l.07 10,lQ 9'1 10111 01 !OS l. 73 lll.~7' 9:! :091 95 1087 Jn 10.i'4t) 99 1087 l-1 10~7' Jti 109\ 53 1094.1'7 lO<°i"' .. °'J 10".-i.17 10"7 "~ lll'.•l "" tu~:.? ~.~

10'.ll.45 I(),•q -l"i

r( z-.,,,,i f'(Z-.ee)

na

(7.U)

is expected to be unity in the Standard ~lode!. The values of the ratios of the partial

decay widths into quarks and leptons are

f(H"-+ qq) = 6.25 ror -+ ev)

[(Z-+ qq) = 21.1. [(Z-+ee)

UA2 quoted a value R = I. 71 ± 0.-15. \Ve find R = 1. 7-1 ± 0. 72.

91

(7.15)

4_>j phce BX/= /~ /'j /±XJJj± j!!XKXj?K° K^±;j Wj±X;jW !±~— _ Q j !X/ /~ /'j >_K9J±~^?W ±jJX~? 00<$$ f mac E nss k j1 iKa' ~! /'j WX7j/ —_== =%jK/;±^— X? ['XK' 7j / j?j±JXj= [j±j K~±±jK/jW ^=X?J /'j —j/'~W Wj=K±X>jW X? ZjK/X~? phch x !^?K/X~? X?;~;X?J _±K/_? T=jj w*^_/X~? phmn' X= ^=jW /~ !X/ /'j /±XJJj± j!!XKXj?K° K^±;j* _?W WX!!j±j?/ ?^—>j±= ~! %~X?/= ~? /'j j!/ _?W ±XJ'/ =XWj= ~! /'j =XJ?_ ±jJX~? _±j X?K^WjW X? /'j !X/ T/~ /'j /±XJJj± j!!XKXj?K° K^±;j'h x j?/±Xj= X? /'j /_>j K~±±j=%~?W /~ !X/= T/~ /'j /±XJJj± j!!XKXj?K° K^±;j' ['XK' '_W ±jW^KjW Q j ;_^j= j== /'_? mhmh

y _ K 9 J ±~ ^ ? W > X / / ± X J J j ± ' / ! ^ ? K / X~ ? » % /= j !/ v » % / = ? K ? / = XJ ? _ w ± ±~ ± ~? = XJ ? _ ]o _ / _ ? b m b macpa c mman mb5hN _ / _ ? u u mnmpu r mmauhmpU e _ / _ ? c c mcab um mmsp na5 A _ / _ ? b as a u m s hb m mmsp nb]o _ / _ ? as assr z mmsr bc]o _ / _ ? ■ as ascc v qQ4 mn]o _ /_ ? u as acpu bp mmsr mc5U _ /_ ? c as ra c r hc u mmmuhua]o _ / _ ? as b m a n hm c mmmbhmb5U _ /_ ? b mc rrpb un mmmuhna]& _ /_ ? 7 mc rarm su mmmn ca5U _ /_ ? mc r aas bc mmmnhmr€ H _ / _ ? u mc rnbr r mmmnhb 7

_ / _ ? c m c bmbc bc m m m r b r ’]& _ / _ ? mc mmcpn n mman sr]o _ /_ ? b ms mamus r mmaa cu5U _ /_ ? ms mmumr p m maa sc5 A _ /_ ? p ms mamap l m mna uu5U _ /_ ? u ms v mbrp u m maa nm]o _ / _ ? l ms mabbb m mmau uu]e _ / _ ? u ms v mrrbhc m map rn]ho _ / _ ? b u mnnnm b mmamhnb5U _ /_ ? b p mnusm r mmau ca5U _ / _ ? b r mabrc u mmanhu5U _ / _ ? c b macpa mmamhsa5N _ /_ ? c ©X m mnns c mmarhrr]o _ / _ ? c p marpb n mmauha

_ / _ ? c s uapc bb mmmp cu

phb g ~?K^=X~?=

x =XJ?_ q » o Q T B ' #l $ — N 1 { X= ~>=j±;jW X? /' j W X7j / — _== =%jK/±^— !±~— _ 0 ^?

vg W _ /_ =_— %j /_9j? [ X/' _ ~[ E/'±j='~W W X7j / /±XJJj±h 4 ' j =XJ?_ X= ~>=j±;jW _ /

_? X?;_±X_?/ — _== K~?=X=/j? / [ X/' /' j vB _?W ' — _==j=h 4 'j — j_=^±jW K±~== =jK/X~? h

q * o Q b B ' El $ — N 1 { f nc hr„ mu ha T=° =' „ u hm T= /_ /' ?> X= K~?=X=/j? /* [ X/' X? j]% j±X— j? /_

j±±~ ±= [ X/' /'j Z /_ ? W _ ±W - ~Wj %±jW XK/X~? h 4 ' j =° =/j— _/XK j ±±~ ± X= W~— X?_ /jW >° /'j

^?Kj±/_ X? /° ~ ! /'j /±XJJj± j!!XKXj?K°h q X?/= ~! _ W~^>jE%j_9 = /±^ K /^ ±j _±j ~>=j±;jWh

4 ' j %j_9= _±j =j% _±_ /jW >° < ms k j1 * /'j — _== WX!!j±j?Kj >j/[ jj? /'j vB _? W H * _?W

/' j ±_ /X~ ~! j;j?/= X? /'j %j_9= X= K~?=X=/j?/ [ X/' /' j Z /_? W _±W - ~Wj % ±jW XK /X~? ~!

q * o ° ' E+ $ — N 1 { \ q » o QT #l■ $ — N 1 { B 4 'j=j ±j=^/= _ ±j ~> /_X?jW ~?° _ !/j ± 7j / K~ ±±jK /X~?=

ba


Table i.5: Fits to the trigger efficiency curve derived from a x2 fit to the background region (mJJ = 125 - 300 Ge\' /c2) of the dijet mass spectvrum in which jet energies were corrected using the method described in Section 7.5. :\ function involving a.rctan (see Equation 7.13) is used to fit the trigger efficiency curvP, and different numbers of points on the left and right sides of the signal region are included in the fit (to the trigger efficiency curve). All entries in the table correspond to fits ( to the trigger efficiency curve) which had reduced x2

values less than 1. 1.

.. ,. ,. ts te t # u r11int ,, na rror on Sl n.1

\: a.tan 9 'l l:!57:!.5 l :!3 l,l \" Atan ,I " !Jl 74 c 11!4.l 7 l.: atan 5 15!9 41 1107.J'..?

\: ata.n ') w :!-110.~t 1107 JG \" d.tclO !O 2006 JI l 100 1'; \: olt.in :.?O !055 l 1107 lJ

\: a.td.11 6 !O 257,-4.17 110~.l.'i

< a.tan .5 !O ti:?56.5S l l 14.~!

\: ,1,ta.n !O ~H:!J. 15 111!1.I!!

l.: a.ta.n !) l .5 61!7!) .'!3 1114.J!

\: a.t.a.n l.5 6!Sl O~ 1113 )-.?

\" a.tan l 5 f.i:?:!0.~5 l l lJ.16 \" Atd.O 6 l5 riJ'.)~ ti ll lJ.!) ," .t.tan l; 11'-15 '.15 ll!,!.'.!,• ,: ,1,ta.n l 5 1157:1 J l l:!3 Gti

\: &ta.n .. 10 l:!l~O 6 112:.?-~,'4 \" •tan LU 1 t.'1lt> 7 lt:.?:.?.O.'l

\~ .. ,..., 10 l:! t:.?':9 .) lL?:!.-l~

\ ,lta.n ~ l•l 1: ~-t;7 ~ ll'.!:!.Jl \, at.1.n 10 1:.!f:..)~lj I 11.!4 ritJ

\~ ,uan lO lltiti<J.5 l l!7 ijJ

\: cltd.O ') lJ.lJl ') l!!I.J'.!

\~ atA.U ')

I 13-IOl ,. l ~:.?·I. "i:!

\: o1,tan 9 6 l:.?96.'i ~ l 1!3.1l

l.: d.tn.n s 9 l:.?5~:! l l:.?•1.0:.? ,· ata.n ,; l lJ3U.5 11:!6.titi

\~ 4t,UJ 7 1267') J u:n . .? '. .a.ta.n .I Ii -127':J_')IJ l l l ~ 14

i.9 Conclusions

.-\ signal a · B(lt", Z --, jet:;) is observed in the dijet: m!1~s spectrum from a Run

IC data sample taken with a low-threshold dijet trigger. The signal is observed at

an invariant mass consistent with the Ir and Z masses. The measured cross section.

a· B(ir. Z -;. jets) = 35.6± l-1.2(sys) ±-Ll(sta.t) nb is consistent, within experimental

errors with the Standard .\lodel prediction. The systematic error is dominated by the

uncertainty of the trigger efficiency. Hints of a double-peak structure are observed.

The peaks are separated by"' 10 GeV, the mass difference between the IV and Z, and

the ratio of events in the peaks is consistent \Vith the Standard .\-lodel prediction of

a·B(Z--, jets)/a·B(H.--, jets). These results are obtained only after jet corrections

92

4_>j phre B X/= /~ /'j /±XJJj± j!!XKXj?K° K^±;j Wj±X;jW !±~— _ € j !X/ /~ /'j >_K9J±~^?W ±jJX~? °S $$ m mac # nss kj1iKa' ~! /'j WX7j/ —_== =%jK/±^— X? ['XK' 7j/ j?j±JXj= [j±j K~±±jK/jW ^=X?J /'j — j/'~W Wj=K±X>jW X? ZjK/X~? phch x !^?K/X~? X?;~;X?J /_?' T=jj w*^_/X~? phma' X= ^=jW /~ !X/ /' j /±XJJj± j!!XKXj?K° K^±;j* _?W WX!!j±j?/ ?^—>j±= ~ ! %~X?/= ~? /'j j!/ _?W ±XJ'/ =XWj= ~! /'j =XJ?_ ±jJX~? _±j X?K^WjW X? /'j !X/ T/~ /'j /±XJJj± j!!XKXj?K° K^±;j'h x j?/±Xj= X? /'j /_>j K~±±j=%~?W /~ !X/= T/~ /'j /±XJJj± j!!XKXj?K° K^±;j' ['XK' '_W ±jW^KjW ;_^j= j== /'_? mhmh

- _ K 9 J ±~ ^ ? ^ ' X / ± X » » j ± ? / !^ ? K / X~ ? » %j? j ! / v =j ?K_ ± X_ ? / — _ ? _ X ' ± ±~ ± ~? — _ ? _ X5< / _ ? ' b b mamcn mmaa hrn5U / _ ? ' r t m n c p b a m mau tn] e / _ ? ' c c a m u p hm c mmsthca5U / _ ? ' b as u bbm ZQ mmmm rr5N / _ ? ' t Es c m r a aUh 8 mahsu] o / _ ? ' p as c a r a hc p mmmahar5U / _ ? ' r as c b p n vZ mmmnhupQ ] / _ ? ' c as m s n b n c mmashbp5U / _ ? ' as m n a u r r mmac pn5U / _ ? ' ° mc p t u m hc r mmmr sm] o / _ ? ' t mc p p u p up mmmc bc5N / _ ? ' p mc p p c a am mmmc br5U / _ ? ' r ml t m p u b mmmr pa

/ _ ? ' c mc masmm c mmanhmp5U /_ ? ' u mc muumr mmaphnt 75U / _ ? ' b ms mm b b b c mmaa nb] ® /_ ? ' t ms mmtcm mmaaha ’5N / _ ? ' p ms v m b n b r mmaahat ’5 UU / _ ? ' r ms v a s s s c mmaa un 7] X / _ ? ' c ms v Untb p mmar ta m] ® / _ ? ' u )s mrncu c mmnsha ’5U / _ ? ' b t m n p c t hp mmahc ma m5 A / _ ? ' b p m npru hm mmac mm5N /_ ? ' ~ r ma u p u hr mman mm5N /_ ? ' c b mn b u u hc mmarhmp5U / _ ? ' c r m c n s n a mmathmt] o / _ ? ' c m u p s c ha mmap n5® / _ ? ' c r b c u s ar m mmb hcb

>_=jW ~? _ ?j[ K_ ~ ±X— j/j± K_ X> ±_ /X~? % ±~ KjW ^ ±j _±j _% % XjW /~ 7j / j?j±JXj= X? /'j

W X7j / =_— %jh

4 'X= = XJ?_ K~^W >j _? X— % ~ ±/_ ? / ±j!j±j?Kj =XJ?_ /~ K _ X> ±_ /j /'j 7j / j?j±J° =K_j

=X?Kj /'j Q b _ ? W ' —_==j= _ ±j 9?~[? /~ J ±j _ / %±jKX=X~?h 8 ?Kj±/_ X? /Xj= ~? /'j 7j /

j?j±J° =K_j K ^ ±±j ? /° X— X/ /' j /~% —_== — j_=^ ±j— j? /h

bn


Table i.6: Fits to the trigger efficiency curve derived from a x2 fit to the background region (m11 = 125 - 300 GeV /c2) of the dijet mass spectrum in which jet energies were corrected using the method described in Section 7.5. A function involving tanh (see Equation 7.12) is used to fit the trigger efficiency curve. and different numbers of points on the left and right sides of the signal region are included in the fit ( to the trigger efficiency curve). All entries in the table correspond to fits (to the trigger efficiency curve) which had reduced x2 values less than 1.1.

t1,u:kicro11no t-·,t rutll~I"' 'lt tunc:,on ,. '" ~tt # nt!i rtitnt :,11,cna c.rror on :1111:na

x: tanh 9 9 l:!l 53 ll :?:.?.63. ! ,._ - tAnh ~ i L3j7g .! 11:u:i ,: ta.nh 5 > :!l.&7.15 llll~-~:.!

:1.: tanh 9 :.!O ·1991 5o Ill! 66 ,- t•nh '! I ·.:o ~16:! '.!: 111·.!.lH ,: tanh 7 !O 5:.?!i!.S~ 1l 1:.?.'.:ti ,- ta.oh ,;

I :.?O 5973. l~ lllJ.17 \: ta.nh 5 :.?O !0393 5 llW ~7 ,: ta.nh

I ~ -.?O 13:.?.itL~ l l~5 73

\: tanh ~ 15 7>!-11.56 t11ti Ol ,: tanh '! I 5 77•17 ~7 l l l5 ~5 ,: tanh 7 I> 7~5:.! :.?l ltl.5 ~6 \" I tc1,nh ,; I; ~17-1 ~ l l lti 7:? \:

I tanh 5 15 t:!011.5 l l:!3.!7

.\ - tanh -I 15 1-1-116 ll:!7 . .1,'\

I \~ t4nh ') 10 t 1999 5 t t·.r.! ~\lj

\: tanh

I • LU lt~,:i l l'!'!.:!

I \ - t.~nh 7 to l l'U!J 6 l L!'..?.~~ \, ta.nh I ,; LO l.!000 5

I ll:!:!.-iJ

I \: t.!.nh

I 5 lU l IJ,"" 1

) 7 ll:!ti !lo:.?

,: t"'nh ·I LO lti:15-1.J :uo.:.? \.: ta.oh ') '

I

t.175~. 7 11:.?., l:.? I \: t.inh ') 7 !37fi-l.t l l!.5 ti \" ta.oh ,, ,; 1~-1,.u l lZJ 11 \: ta.nh 5 1 lJ~·l-&.5 ll:.?fi.17

\: ta.nh ,. ., t5JOJ ! l l!S. l ~

< t.a.nh 5 7 L-t7U~.l 1 t:.?7.3 ,- t,nh 5 ,; 9.'i-10 :!ti 111 1) 59

based on a new calorimeter calibration procedure are applied to jet energies m the

dijet sample.

This signal could be an important reference signal to calibrate the jet energy scale

since the H · and Z masses are known to great precision. C ncertainties on the jet

energy scale currently limit the top mass meru;urement.

93

4_>j phpe BX/= /~ /'j /±XJJj± j!!XKXj?K° K^±;j Wj±X;jW !±~— _ X9jX'~~W !X/ /~ /'j >_K9J±~^?W ±jJX~? °0**$$ f mac # nss kj1iK<' ~! /'j ±_[ WX7j/ — _== =%jK/±^— T?~ 7j / j?j±J° K~±±jK/X~?='h B^?K/X~?= X?;~;X?J _±K/_? _?W /_?' T=jj w*^_/X~?= phmnh phma' _±j ^=jW /~ !X/ /'j /±XJJj± j!!XKXj?K° K^±;j X? _ ±jJX~? [ ' j ±j ?~ =XJ?_ X= j ] % j K /j W * *<$$ m b s E m m s kj1iKah ,X!!j±j?/ ?^—>j±= ~! %~X?/= ~? /'j j!/ _?W ±XJ'/ =XWj= ~! /'j =XJ?_ ±jJX~? _±j X?K^WjW X? /'j !X/ T/~ /'j /±XJJj± j!!XKXj?K° K^±;j'h x j?/±Xj= X? /'j /_>j K~±±j=%~?W /~ !X/= T/~ /'j /±XJJj± j!!XKXj?K° K^±;j' ['XK' '_W ±jW^KjW °a ;_^j= j== /'_? mhmh 4'j —j_? ;_^j ~! /'j ?^— >j± ~! j;j?/= !~± _ !X/= X= K~?=X=/j?/ [X/' \j±~h

' X / v ± XJ J j ± ' / ! ^ ? K / X~ ? U % ? j // » % / = ± Xd ? / © Z XJ ? _ ' ± ± ~ ± ~ ? UXd?_ X9 j X' ~ ~ W x /_? c v ■c'm a 6 v acm h♦z X9 j X' ~ ~ W _ /_ ? t c ■ucb v vZ acg nnc X9 j X' ~ ~ W _ /_ ? p c ■cs hsnuu acm htrr X9 j X' ~ ~ W _ /_ ? r c ■tt hsnua acmhpua X9 j X' ~ ~ W _ /_ ? c u Eant mnc acshbtu X9 j X' ~ ~ W /_ ? ' zsu ac n an X9 j X' ~ ~ W /_ ? ' c c ■b n hpnrr acm pamX9 j X' ~ ~ W / _ ? ' p mc nbc mpb acn hcpu X9 j X' ~ ~ W /_ ? ' r mc nunhum acn nptX9 j X' ~ ~ W /_ ? ' c mc asm mbr aca hnua X9 j X' ~ ~ W /_ ? ' u mc mpb ra a c a hpcb X9 j X' ~ ~ W /_ ? ' ms anp rrr a c a hbppX9 j X' ~ ~ W /_ ? ' r ms ©nphmauc acm hbncX9 j X' ~ ~ W /_ ? ' c ms nt npba acah mma X9 j X' ~ ~ W /_ ? ' ms c ■a mc hcmr ac m hacb X9 j X' ~ ~ W / _ ? ' b c Emrs rcp acm hnbm X9 j X' ~ ~ W /_ ? ' ■c p u zb aca scuX9 j X' ~ ~ W /_ ? ' ms u Eabs hmpn a c s hb p p X9 j X' ~ ~ W /_ ? ' c s n n n hp a p acn hnum X9 j X' ~ ~ W ■ _ ? ' c dabhrsc a ca rsr X9 j X' ~ ~ W /_ ? ' c p mcchptb a c a hr r t X9 j X' ~ ~ W /_ ? ' c U hEn r ntam a c m hncc

bu


Table i. i: Fits to the trigger efficiency curve derived from a likelihood fit to the background region (m11 = 125-:J00 GeV /c2 ) of the raw dijet mass spectrum (no jet energy corrections). Functions involving arctan and tanh (see Equations 7.13. 7.12) are used to fit the trigger efficiency curve in a region where no signal is expected. m 11 = 90 - 110 Ge V / r?. Different numbers of points on the left and right sides of the signal regiou arc included in the fit (to the trigger efficiency curve). All entries in the table corrcspoud to fits (to the trigger efficiency curve) which had reduced ,y2 values less than 1.1. The mean value of the number of events for all fits is consistent with zero.

.. , ,,. n.t.tt"r ht tunct1011 ,,. Jt'I • t # pts r1..:t1t ::"'111(041 r.rrr>r •ln 11.rn.t.1 l111!.et1t1uut.1 ata.n ,

' ·'Jl . .;'J~i .. .lL ,.\ likelihood at.i.n ~ 5 -·1.5'1 -11~ !5G 335 likelihood at3.n 1 5 -50.0J·H 151.:!~t) likehhood ata.n ij 5 -~8.03-1! :!51. 7-l:.! likelihood &tan 5 ~ -2~-'4 135 150.~N-I ilkehhood t.anh .>u• -Id~ >>J OJ hkeJihood tanh 'i .5 .!)J.~:.?firi :.?.1H.7:.?l likelihuod to1.nh 15 39.5.1,!l :?5J . .'i'7.& lakelihood tanh 6 15 3·13.11 253.J7., likelihood tanh 5 15 201 l!iti 25:.?.~4:.? likelihood tanh 4 15 l 79 6:? 25:?. ;'.54.) liKehhood tanh 10 :?:17 666 :?5::L'J77 hkelihooc..i tanh 6 10 -.17.t:HS !51.~35 likelihood ta.nh 5 10 -'8 .1792 25.?. ll:.! likelihood ta.nh 10 5 -!15.5111 :!51..!.~'J tlkellhood ta.nh 9 5 -180 S57 ~51.391 likelihood l.1.!lh 6 < -5 HJ'l :.?5:? O~.\ likehhood tanh 10 4 -290.173 250.977 likelihood tanh 5 9 l3J. 727 !5J.JH likelzhoorl •anh 5 • ':!9.605 2s·.? 60ti lakohhood tanh 5 7 I ISS.789 252.titi-1 l&kPlihood t4nh ~ ~ --5~ JR2 l ~51.S5.~

94

eOOO ]%

1OOO 5*R

GOOO Y*p

EOOO

msss

s

7 w—?j= X 6jj? p Tah

uaUUps npaa nhngbt A

• 9 E*G

s ahn rt ms

=OOO

VOOO

eOOO

1OOO

GOOO

EOOOmsss

s

■ 7 u a U u p ’

]CpB C+ j K ? s h n - u Ap T|’ n hn p u p o

pp_ FF

p7 • f E*GE)^

^X

F

5>;

5 F *= AE m R R C I R

rt ms

k¥ k*k]~D

0OO ± =OO 9* VOO ]css ± *_uss S

-66 ZZ R QEOO ">mss ’7

s8

p• 6jjUv

• 9 G*1

p t m u

m a 4 zI nru

rt ms

0OO=OOVOOeOO1OOGOOEOOmss

s

wEwzX

;

,cJ k*k]~D

© w?/±Xj= v -jK? v U1Z

• 9 G*1

gEvjc*\

1

ahn rt

ltmu v mEarn ’ »j rr

ms


B XJ^±j phne ZXJ?_ WX=/±X>^/X~?= !~± /'j Kj?/±_ jjK/±~—_J?j/XK K_~±X— j/j± _?W /'j Kj?/±_ '_W±~?XK K_~±X— j/j±h ,X=/±X>^/X~?= [j±j ~>/_X?jW !±~— X=~_/jW /±_K9= X? 0^? vy —X?X—^— >X_= W_ /_ _?W _±j ='~[? !~± '_W±~?= [ X/' % f a E n k j1 iK _?W % f n E u kj1iKh Zjj /j]/ !~± Wj/_X=h

bc


5000 r.. ! £r,tries ,2.,1 ~ ' £ .. tr,e3 .,447 l

r I 1 \lccn a a122 7000 c- 1 V~c., O.d~ l .& I

: ~\IS J.dC9e - ~ i ~vs :.;u.7;

4000 r . 6000 ~] ..... " ' -, t > 5000 ,....,

:Ji 3000 1--i: p =2-3 4000 - 'I p = 2-3 t ! l1 _, ~-;

2000 ; ! : 3000 .:-.' r• -., ~, I C ( ~; : i' ~, 2000 \.. E7 ;,,

1000 ..... ~)

--.,, 8 -..,, 1000 --

'- El 0

'r-: 0 -.

0 ., --~ 5 7-5 10 0 ., -.. :, 5 7-5 10

em energy had energy

800 ; f:o,t~,., 7814

800 fr1

; E:ntr,n I~" I

: 1 l Vt!C" , iu I \leC"'I 1.ldS I

700 I Wl.t$ 1 J6,C I ~\IS ·.2,0 I c: 700 ..... , 600 ~t 600

~ 1 I c:-' I

ff 500 ,

ti1 500 I

~: I 400 ~ll p =3-' 400 - . I p=3-'

~1 JOO ~ ttl.1 JOO E..; l

e:; 1i 200 E1 200 ~ "'"---U tJ ,.., 100 1..., 100 2 . -,

~ .._. t: '--i.,.._

0 0 F 'I I I -"=--0 , --.!' 5 7.5 10 0 ., -. .;:, 5 7.5 10

em energy bad energy

Figure 7.3: Signal distributions for the central electromagnetic calorimeter and the central hadronic calorimeter. Distributions were obtained from isolated tracks in Run IB minimum bias data and are shown for hadrons with p = 2 - 3 Ge V / c and p = 3 - -! Ge V / c. See text for details.

95

F0O /G

d 00

"?/ 0*—q 6jj N

■bzp m csb F1O Y m

w?/±jU-jK!

mb z r ’e h_ K ~ m

FVO _ ^ = ■ / X _[= I rj j m]p> FEO ,Bp IF1O / ± X v ± 7

FEO _ FOO ± vF

FOO0O lpp

• 9 1*e 0O

VO

X Em

B E

• 9 1*e p

7

VO % ] ; h!A1O ’ ’ g s

5©?EI vm 1 AE©d[

1O Y©u Am5> £ / G FF

mmEO

m hEO

& 7 1 B I

O ±Y vUhUh #m h O [ * l l B B B . h

O ECe e =Ce FO O ECe e =Ce FO


‘O . 0O .® =O VO eO 1O GO as ms s

w '± !! X

p >%7ZX*

"±/X?j=^ j K E■u-Z

nacm nmp e p.3

U Ezm ? X± 7 X z ?4XI

=Ce

k¥ k*k]~D

ms

1O BGe 2 2GO mEeEO

: q

xX > ]_ m mFe w X ® N [FO qe d Z

d ;E

O " ■

O

"U- ±»1jKUA±/;Z

bac ahizi ’ j ham Y ’

q v

us e =^

,cJ k*k]~D

ms

B XJ^±j phue g j?/±_ jjK/±~—_J?j/XK _?W '_W±~?XK K_~±X— j/j± =XJ?_ WX=/±X>^/X~?= ~>/_X?jW !±~— X=~_/jW /±_K9= X? 0^? vy —X?X—^— >X_= W _ /_ [X/' % f u E c kK1 _?W % l c kj1iKh Zjj /j]/ !~± Wj/_X=h

br


180 E

160 ~l 140 S 120 :i

100 ~ P = -'-S 80 E-7! 60 E-11. -40 8 11:iJ'': r-:J'l... 7 ~· I , ' f.i; 20 ~ J11~ .. 0 ~. ·:.,.l_,,

0 2.5 5

em energy

90

= ~ 50 UI t;Ji

..ffl E!~ JO ~:

fil 1..,, , ~ 20 c, • • ~ ·"' :'I r I ... " ll..-i.ll

. \leCl"I

I ~MS

p>S

IO~ -:/u"U'l 0 ~ r"T:'4-",..,

7.5

-9~7 I 5C9 • J67

12~ ' 31 / T 718

10

0 2.5 5 7.5 10

em energy

140

120

100

0

40 _

0

j Entr-es , U•c:, I 'll.lS

p = -'·S

., -__ :, 5

had energy

. :_.,,,,., , \lee.., I ~vs

p>S

had energy

7.5

19.J,l T.dCO I '521 :

10

9.25 UJl: 2.2 T ' I

Figure i.-1: Central electromagnetic and hadronic calorimeter signal distributions obtained from isolated tracks in Run IB minimum bias data with p = --1 - 5 GeV and p > 5 GeV /c. See text for details.

96

EOOO

msss

s

e Em’ w?/XEh- mkgsg

FeOOE ■~K~~7 -jK? p abu U# 8±KEU !U bu

± X A v 1rpg X v a cprB z X FOOO K h 7U± U *

n° U heOO # X )* mm

O 5 ■ h ± ; vO EO 1O VO O EO 1O VO

(. . . ]

eOO .*±

ss

w7j/fms kj1

±mV Ai m

* . ~ K K Kv -gv aahnrI q-gGGGGGGGGGGGG z nUr

as 1O VO

msss=eOeOOEeO

s

w7j fas kj1

* g E E j X AagsgE o -»gEX 4z hY Az-.GGGGGGG uhcrc

v

EO 1O VO

0OOVOO1OOVOO wE

!

EOO ]B

s

w7j/fns kj1

c 8/!K?Z-Z

v

beO

± Q g Q g nbhan A chdbr

=e mss

VOO

1OO

EOO

s

■)G

[

w7j!fus kj1

* —w?/±EjU-jKEU©;c

± h h p h _eO =e

■kgQg ’ dp ra or U s A 7

mss

w7j/fcs kj1 w7j/frs kj1

BXJ^±j < hce zj / =XJ?_ W X=/±X>^/X~?= ['XK' ±j=^/ !±~— =X— ^_/X~?= Wj=K±X>jW X? /j]/h qj±jh - j/'~W vvv [_= ^=jW /~ =j/ /'j j?j±J° =K_j ~! /'j Kj?/±_ '_W±~?XK K_~±X— j/j±h ,X=/±X>Ê/X~?= _±j ='~[? !~± 7j/ j?j±JXj= ±_?JX?J !±~— msErs kj1h

bp


.1 2000 ;:- ,~

~ - I 1000 t:.. · i.

I £~1,,e5

i l,le,,e <IMS

IGCOC 729• , .67C

: ? l 0 ._, __ .._._ __________ ~__.___

0

1000

500 r ..

0 0

. 800 E-.. 600 c..

.fflO E.. ~

200 ~ 0

0

20

,l J

20

40 60

I ~:~~~ !2~~~~ ;_RM~-~-- j j4€ •

40 60

,..~ I ~:~n,n !CCOC ••• J9.2~ '

1 , _R--'u~s ____ 5=-•~9"-6

/ ll ' \ J

25 50 75 100

1500 -. .. 1000 ;-

500

0 0

1000

750 500 -

20

250 I t

I £"t,1~ , U.C"

i s\lS

40

1 £:'\tr·e,

' ' , VdC.,

l

60

·ocoo I ~4 ~" l_ 576 t

·:xoc i j' 'j

•.S6J

0 ·:__ __ .,;:__r ___ ~----...-i 0 20

25

40

50

E. =60GeV Jet

60

':;~ I ,;..:i,'

75 100

Figure , .. 5: Jet signal distributions which result from simulations described in text. Here. Method III was used to set the energy scale of the central hadronic calorimeter. Distributions are shown for jet energies ranging from 10-60 GeV.

97

q F mEecC»»0B OC‘e

im

M E

W<#c OC‘ I®

OC0e 0

OC0 0OC=e p

OC= Z0*

OCVe ,

OCV 'v

OCee p*I

OCe F

-j/'~W m

-j/'~W X

ms ms

)k> 5*k]~D S3ks'

B XJ^±j phre zj / ±j=%~?=j K^±;j= !~± g, BA= /±_WX/X~?_ — j/'~W ~! Wj/j±—X?X?J /'j j?j±J° =K_j ~! /'j '_W±~?XK K_~±X—j/j± =jK/X~? T- j/'~W v' _?W _ ?j[ —j/'~W ~! =j//X?J /'j '_W±~^XK =jK/X~? j?j±J° =K_j T- j/'~W vvv'h 4 'j ±j=%~?=j X= ?~±—_X\jW /~ /' _ / ~! jjK/±~?=h 4 'j X?;j±=j ~! /'j ±j=%~?=j ±j%±j=j?/= /'j K~±±jK/X~? !_K/~± !~± /'j _>=~^/j 7j / j?j±J° =K_j T=jj w*^_/X~? phms'h

bt


;.I 1 I

~ I

= '-I

Q. 0.95 -;,i ' ;.I

==: - 0.9 ;.I -..,

0.85 I

,..

0.8 I-

0.75 i ~

0.7 r

0.65 r ~ • Method I I

0.6 r I

1,1 "- • Metricc '" 0.55 ~

I ~

0.5 10

Jet Energy (GeV)

Figure ,.6: Jet response curves for CDF's traditional method of determining the energy scale of the hadronic calorimeter section (Method I) and a new method of setting the hadronic section energy scale (1[ethod III). The response is normalized to that of electrons. The inverse of the response represents the correction factor for the absolute jet energy scale (sec Equation i.10).

98

ms

GO 1O cs VO =O 0O ‘O mss

8p_k■ 2*|c]pc*■ nc’’S3kw=y-'

BXJ^±j phpe 0_[ WX7j/ X?;_±X_?/ —_== =%jK/±^— h P~ j?j±J° K~±±jK/X~?= '_;j >jj? _%%XjWh 4'j /[~ 7j/= [j±j ±j*^X±jW /~ >j >_K9E/~E>_K9 TK~= d!l d Es hu ' _?W j;j?/= X? ['XK' _ /' X±W 7j / [ X/' UP l mc kj1 [_= %±j=j?/ [j±j ±j7jK/jWh 4'j =/jj% !_~!! >j~[ cs kj1iKz X= _ ±j=^/ ~! /±XJJj± X?j!!XKXj?KXj=h

bb


L -- --' ----r --i r

10 .. ·_ - --I - --:... -- -- ---:... --i.. --I --:...

r I I ! i

10 3 f-r-

30 40 50 60 70 80 90 100

Dijet Invariant Mass(GeV/c2)

Figure 7.7: Raw dijet invariant mass spectrum. ~o energy corrections have been applied. The two jets were required to be back-to-back (cos < -0.4) and events in which a third jet with Er > 15 Ge V wa:; present were rejected. The steep falloff below 50 Ge V / c2 is a result of trigger inefficiencies.

99

ik"■¥^’■ •^p*■ ^" "p■■kJ ¥c’’ ]k~p^* S3ksLyE'

BXJ^±j phte 3^_X/° ~ ! j]%~?j?/X_ !X/= /~ /'j WX7j/ X?;_±X_?/ —_== =%jK/±^— ~;j± _ X— X/jW —_== ±_?Jjh Z'~[? X= /'j T!~± an WjJ±jj= ~! !±jjW~—' _= _ !^?K/X~? ~! /'j ~[j=/ —_== %~X?/ ~ ! /'j uc kj1iKa [XWj WX7j/ —_== ±jJX~?h Zjj /j]/ !~± Wj/_X=h

mss


- ! i= r-

'= I • 'C

10" ~ ~ r.. • ; r--l • :a ~ ~ •

rn3 L • -c-! r r ' . ;

10 • ;::--

E r r r-

I !, I

40

•

• • •

50

. -~--. - . ·-·· ----.

60 70

•

•

80

... • ••••••. I •• • • • e• eeel •• •

I ,

90 100 110 120 130 • Leftmost point of fitted mass region (GeV/c·)

Figure 7.8: Quality of exponential fits to the dijet invariant mass spectrum over a limited mass range. Shown is the x2 (for 23 degrees of freedom) as a function of the lowest ma.-;s point of the 45 GeV/c? wide <lijet mass region. See text for details.

100

msssE ) E E0OO

VOO

1OO

EOO

s

EOO

*1OOeO VO =O 0O ‘O FOO

8p_k■ 2*|c]pc*■ nc’’ S3ks'

F1OO %

FEOO 5 FOOO w0OO %

VOO w1OO s ; EOO 5

s %

*EOO w

*1OO ceO VO =O 0O ‘O FOO FFO

8p_k■ 2*|c]pc*■ nc’’ S3ks'B XJ ^ ±j phbe 0j=XW^_= [ 'j? _? j]%~?j?/X_ >_K9J±~^?W X= =^>/±_K/jW !±~— /'j ±_[ WX7j/ —_== =%jK/±^— T_' _?W !±~— /'j WX7j/ —_== =%jK/±^— X? ['XK' 7j/= _±j K~±±jK/jW ^=X?J - j/'~W vvv T>'h 4'j !X/ ='~[? X= /'j =^— ~! /[~ k _^==X_? WX=/±X>^/X~?= X? ['XK' /'j WX!!j±j?Kj >j/[jj? /'j /[~ —j_?= _?W /'j ±_/X~ ~! /'j [ XW/'= ~! /'j /[~ J_^==X_?= [j±j !X]jW* >^ / _ ~/'j± %_±_— j/j±= [j±j j!/ !±jjh Zjj /j]/ !~± Wj/_X=h

msm


t: 1000

t tt t r--

800 ~ a) ~ 600 c I-

-'00 L--I r-C

200 ...... ' t 1 :-

0 i

'-

i T I I C

I I -200 '--- J,: I

,.....

I I t I C I I I I I I I I I -400

50 60 70 80 90 100

Dijet ln,·ariant Mass (GeV)

'-

uoo ~ b) 1200 ,..... - i

1000 E-!-

800 :---600 r-r-r-

r-

400 -!-

200 I-I"-

0 E i-

-200 ;::.... C I 400 - I

50 60 70 80 90 100 110

Dijet Invariant Mass (GeV) Figure 7.9: Residuals when an exponential background is subtracted from the raw dijet mass spectrum (a) and from the <lijet mass spectrum in which jets are corrected using Method III (b). The fit shown is the sum of two Gaussian distributions in which the difference between the two means and the ratio of the widths of the two gaussians were fixed, but all other parameters were left free. See text for details.

101

' ±

Cums

ms a

ms

m

cs mss EOO nssmcs ncs ussacs

8p_k■ 2*|c]pc*■ nc’’S3ksLy-'

B XJ^ ±j phmse 0_[ WX7j/ —_== =%jK/±^—h Z'~[? X= _ !X/ /~ /'j =%jK/±^— X? /'j ±_?Jj macEnss w — b \5ah 4'j !X/ X= j]/±_%~_/jW /~ ~[j± ;_^j= ~! WX7j/ —_== X? ~±Wj± /~ j]/±_K/ _ /±XJJj± j!!XKXj?K° ;= WX7j/ —_== K^±;jh Zjj /j]/ !~± Wj/_X=h

FOE


;-

10 3 ~

[

., .

10 - =-~

' I

10 § r-

F r-

1 b-50

\ \

\ \

100 150 200 250 300 350 .&00

., Dijet Invariant Mass(GeV/c-)

Figure 7.10: Raw dijet mass spectrum. Shown is a fit to the spectrum in the range 125-300 Ge V / c2. The fit is extrapolated to lower values of dijet mass in order to extract a trigger efficiency vs dijet mass curve. See text for details.

102

m

OC0

OCV

shu

OCE "

cs rs ps ts bs mss

8p_k■ 2*|c]pc*■ nc’’S3ksLy-'

B XJ^±j phmme 4±XJJj± j!!XKXj?K° K^±;j ±j=^/X?J !±~— WX;XWX?J /'j ~±XJX?_ WX7j/ W _ /_ T±_[' >° /'j j]/±_%~_/jW X/ /~ /'j >_K9J±~^?W ±jJX~? macEnss k j1 iK±h Z'~[? X= _ !X/ /~ /'j W_ /_ [X/' /'j !^?K/X~? _±K/_?h Zjj /j]/ !~± Wj/_X=h

FOG


r -' ;....

! ;....

r 0.8 r-

r-

I r

0.6 r-;....

0.4 I r f-I r-

0.2 '--I r L

0 I ' I

50 60 70 80 90 100


Figure 7.11: Trigger efficiency curve resulting from dividing the original dijet data (raw) by the extrapolated fit to the background region 125-300 GeV/d-. Shown is a fit to the data with the function arctan. See text for details.

103

mcss EEE

Lmacs

Omsss ±

?

pcs #± o

css LLeI

acs

±s

%XEacs #

Ecss©+

cs rs ps ts bs mss

8p_k■ 2*|c]pc*■ b2c’’S3 ksLyE'

BXJ^±j phmae 0j=^/X?J =XJ?_ ['j? /'j ~±XJX?_ W _ /_ T±_[' X= WX;XWjW >° _ !X/ /~ /'j /±XJJj± j!!XKXj?K° K^±;j ='~[? X? BXJ^±j phmmh

msu


;_

1500 ....

r= -1250 :7 I

ti 1000 ri

8 ,_ I L:

750 ~ r: I .-~

500 ~ :- i C1

250 ~! ~ i =1

0 :I T' r1-_, -- '

-250 f-~· r I

~ i I

-500 r:_ -' I C:I I I I . , , '

50 60 70 80 90 100


Figure 7.12: Resulting signal when the original data (raw) is divided by a fit to the trigger efficiency curve shown in Figure 7 .11.

10-1

8p_k■ 2*|c]pc*■ nc’’ S3ksLyE'

BXJ^±j phmne 0j=^/X?J =XJ?_ ['j? /'j ®- j/'~W vvv WX7j/ —_== =%jK/±^—N X= WX;XWjW >° !X/ /~ /'j /±XJJj± j!!XKXj?K° K^±;jh

msc


1500

1000

500

0

-500

,..

i--l ~

' I I I '

i i :T r I I I ' I , I I I I

I i

': _,,

.... I : J.-1 .... I ..... 11 __ : '-11....J.-1 .... I : ___ , ..... i , ___ ..._1 .... I ... , _.I ........ ' -'---'---'----'----'--.:......,..---'------'---'---'--'-'----' ~1 --'-' ---'-'' _l, _L ,_._1 .... I _..___.

65 70 75 80 85 90 95 100 105

Dijet Invariant Mass (GeV/c2}

Figure i.13: Resulting signal when the "'.Method III dijet mass spectrum'· is divided by a fit to the trigger efficiency curve.

105

4 _> j phte BX/= /~ /'j /±XJJj± j!!XKXj?K° K^±;j Wj±X;jW !±~— _ !X/ /~ /'j >_K9J±~^?W ±jJX~? TPPZOO I mac E nss k j1 iK±' ~! /'j ±_[ WX7j/ —_== =%jK/±^— T?~ 7j / j?j±J° K~±±jK/X~?='h B^?K/X~?= X?;~;X?J _±K /_? _?W /_?' T=jj w*^_/X~?= phmnh phma' _±j ^=jW /~ !X/ /'j /±XJJj± j!!XKXj?K° K^±;j X? _ ±jJX~? [ ' j ±j ?~ =XJ?_ X= j ] % j K /j W * 00<$$ f b s E m m s kj1iK<h ,X!!j±j?/ ?^—>j±= ~! %~X?/= ~? /'j j!/ _?W ±XJ'/ =XWj= ~! /'j =XJ?_ ±jJX~? _±j X?K^WjW X? /'j !X/ T/~ /'j /±XJJj± j!!XKXj?K° K^±;j'h x j?/±Xj= X? /'j /_>j K~±±j=%~?W /~ !X/= T/~ /'j /±XJJj± j!!XKXj?K° K^±;j' ['XK' '_W ±jW^KjW Q j ;_^j= j== /'_? mhmh 4'j —j_? ;_^j ~! /'j ?^— >j± ~! j;j?/= !~± _ !X/= X= K~?=X=/j?/ [X/' \j±~h

B X/ » ?dJ»U± !X/ ! ^ ? K / X~ ? » % / = l / / N N ~ / = ? J X X / m - J ? _ X I ( ±±~ ± ~ ?_ /_ ? z u n ■m r r hn s a ars n u b a

5U x /_? p p nb habpm arm r a c b€ N x /_? c c mnm asU arm b n s n5hN x /_? s mc mbs bmm ar a assm5 N x/_? q v c n sa a u r arm uUcu

m H> _ /_ ? mc m a m hssr arm bn u5U x /_? r mc ar ncpu arm cpc5v _ /_ ? c mc as b ncm ara a rb5v _ /_ ? u mc ast asm ara aru5 v x /_? ms Enu masn arm n u b5v _ /_ ? ms ■m m s hb s u arm s c p5v _ /_ ? c ms asn mUn ara ac5v _ /_ ? n c ■nUr uUp ars s m n m5v _ /_ ? c Ea n u hm a r a r s cb c5v _ /_ ? c Ea U p acr ar s n b n5U _ /_ ? m c mcm crc ar a s c p5v _ /_ ? c s acs rbc ara un5v _ /_ ? c n amb usr a r a hn s b5U _ /_ ? c u a s brum arm c rr] X /_ ? ' c ar m hp U n ar a upn5U /_ ? ' ms mc En r s usc a rs mm5U /_ ? ' x mc ■a pn hmun a rs ma5v /_ ? ' c mc pmu nru ar u hm n m5U /_ ? ' u mc r c a hm n b a r n hb u c5E /_ ? ' ms Eu c a hm r p a c b hp r n

a / _ ? ' p ms ■ mrp hnpn a r s ht u c5U /_ ? ' r ms Eamc acn a r s hr r n5v /_ ? ' c ms mushura ara smm5U /_ ? ' 0 c ■r nu hunm a c b hs p cv2 / _ ? ' c u s t hr c u a r n hs n r5v /_ ? ' r c n r n hr a u a r a hn t n5v /_ ? ' u c anp nn a r a hn t u5v /_ ? ' c b uc p nu n r n ha m u5v /_ ? ' c t muu harr a r a hs a c5U /_ ? ' c u msb mmc h■rm Ez

FOV


Table 7.8: Fits to the trigger efficiency curve derived from a x2 fit to the background region (mn = 125 - 300 GeV/c-) of the raw <lijet mass spectrum (no jet energy corrections). Functions involving arctan and tanh (see Equations 7.13, i.12) are used to fit the trigger efficiency curve in a region where no signal is expected. m11 = 90 - 110 GeV /c2 .

Different numbers of points on the left and right sides of the signal region are included in the fit (to the trigger efficiency curve). All entries in the table correspond to fits (to the trigger efficiency curve) which had reduced x:.? values less than 1.1. The mean value of the number of events for all fits is consistent with zero.

ht # lrhtl( .. r ht run«:t1,•n # ~t.,; .t"ft # pt'i rll(ht :-iuc:11,, r.rrur on ,jJl(fMl I

\: o1.tan ' o\ ; -166 . .JO:.? !t,I,) -"'-I')".! I \" 4tAn i i J~. :.!971 :.!til.6:.!59 \: 4tAn 5 5 131 ;.?I)~ ltil ,i;o:i

I \: d.tAn ') 15 !90 ,J!I :!'>:.! .!001 \" ,u,,n o\ l" J.O:?:.?-lti .!tH l"'-'°>-1

' \~ I .\.t41\ i l '."> L:.?t.0')6 ·~,;l '.U-1 I

I \: .ttAn ,; l 5 :!fi J.~7'-1 ~61 57'5

I \: atan I l lo; :.!O'J.351 :!ti:? .!t>~•

\: o1t.-1n ~ l 5 :?Od :!Ol ·.rn:.? :.?ti-I

\: 4tcUl i IO -J~ 1~0; :!fil .1-1!)

I < &t.an 0 Ill -110.90,'i ~61.0H

\: atac > 10 :!OJ. ll4.1 :.?ti:?.:.!~

\: a.t.Ln o\

I 5 -3~6 ~:;i '.!'50 OlJ

< t1.t.1.n i 5 •:.!J-1.1:.?6 :?60 .S95

I t: 4ta.n ,; 5 ·:?~7 :.?.'\6 :160 39J

t: a.t,n I 5 1.51565 :!ti:! 05i

t: 4ta.n 5 •j 250.69.S !6!.-IJ

I t: Atan 5 " :.?19 .io6 -.!ti:.?.30-..+ ,· Atolin 5 4 20 9641 :?61 506

x: tanh 5 5 ".:!6l.7~J ".?62. ,175

:i:: tanh 10 !5 -360.405 26011

\: t.:.nh • I~ -!7,.1-t~ :.?60.,1:!

:i:: ta.uh 5 15 714 364 26-1.l"l

t: t&nh ~ 15 652.139 263.!HS i· t-nh ~ 10 -452. !67 25~- j63

x~ tanb 7 10 -167.37,,1 260.8-15

\: tanh 6 10 •:.?15.:!53 ~60.663

i: tanh 5 ltl 140.462 262.0II t· ta.nh ; 5 -634.431 :?59.075

le~ tanh 7 5 -tO/l.65-t 263.0lti

t: ta.nh ,; 5 J6'!.6H 2ti2.al!3

\~ tanh 4 5 237,lJ 26:.?.JS-I

x: tanh 5 9 -t.57 .~ :!6J.:.?l-1

.\~ tanh 5 I! !H.266 20:!.025 ,· ta.nh 5 4 10'1 115 :.?tit ')

106

g q x L 4 w 0 t

Z8 - - x 02 xP, gQ P g )8 ZvQ P Z

v? /' X= /'j=X=* =j;j±_ = /^ W Xj = X?;~;X?J /' j j?j±J° — j_=^ ±j— j? / ~ ! % _ ±/XK j= ^=E

X?J K_~±X— j/j±= _±j %±j=j?/jW h v? ZjK/X~? uhph _ =/^W° ~ ! /' j j!!jK/= ~ ! ±_W X_ /X~?

W_— _Jj ~? /'j ±j=%~?=j ~! _ % ±~ /~ /° % j !~± /'j g ~— %_K/ - ^~? Z~j?~XW Tg- Z' ;j±°

!~±[ _±W K_~±X— j/j± X= Wj=K±X>jW h 6j !~^?W /' _ / /'j j!!jK/= ~ ! ±_W X_ /X~ ? W_— _Jj ~?

/'j K_~ ±X— j/j±A= ±j=%~?=j _ ±j W~=j Wj%j?Wj?/ _?W /' _ / — ~=/ ~ ! /'j W_— _Jj [X ~KE

K^± X? /'j !X±=/ °j_± ~ ! ±^?? X? J _ / /'j )_±Jj q _W±~? g ~XWj± T)q g'h y _=jW ~? ~^±

=X— ^_/X~?=* _ !/j± ms °j_±= ~ ! ±^?? X?J * /'j j?j±J° ±j=~^/X~? !~± cs kj1 % ' ~ /~?= [X

>j WjJ±_WjW >° msR X? /'j ±jJ X~? ~! /'j W j /j K /~ ± /' _ / ±jKjX;j= /' j — ~=/ ±_W X_ /X~ ? h

v? ZjK/X~? khuh _? j;_^_/X~? ~! /'j %j±!~±— _?Kj ~! _? _ J ~ ±X/' — K_jW /' j w?j±J°

B~[ - j/'~W Tw B- ' X= Wj=K±X>jW h v? /'X= — j/' ~ W * /'j X? !~ ±— _/X~? !±~— /' j K_~±X— jE

/j ± =°=/j— X= K~— >X?jW [X/' /' _ / !±~— _ ' XJ'E±j=~^/X~? K'_±JjWE%_±/XK j /±_K9 j± X? _?

_ //j — % / /~ X—%±~;j /'j j?j±J° ±j=~^/X~? !~± 7j / — j_=^±j— j?/=h 6j !~^?W /' _ / /'j

w ?j±J° B~[ - j/'~W %±~;XWj= _ / >j=/ _ nsR X— %±~;j— j?/ X? j?j±J° ±j=~ ^ /X~? !~± /'j

j?j±J° — j_=^±j— j?/ ~ ! 7j /= h 4 ' j X— %±~;j— j?/ WjK±j_=j= _ / ' XJ' j?j±JXj= [ 'j±j /'j

' _W ±~? XK K_~±X— j/j± ±j=~^/X~? W~— X?_/j= /'j * ^ _ X/° ~! /'j 7 j / j?j±J° — j_=^±j— j?/=

y ~/' =/^WXj= Wj=K±X>jW _>~;j '_;j >jj? %^>X='jW T~± _KKj% /jW !~± %^> XK_ /X~? '

/'j /'j =KXj?/X!XK X/j ±_ /^ ±j h 0 j% ±X? /= ~ ! /'j=j %_% j±= K_? >j !~^?W X? x %%j?WXKj= x

_ ? W gh v %_°jW _ K±^KX_ ±~j X? > ~ /' =/^WXj=h

4 ' j — _X? j— %'_=X= ~! /' X= /'j=X= X= ~? _ = /^ W ° Wj=K±X>jW X? g ' _% /j ±= c _?W ph

v? g ' _ % /j ± ch _ = /^ W ° ~ ! /' ±jj K_ X> ±_ /X~? — j/' ~ W = !~± _ ~ ? J X/^W X?_ ° =jJ— j?/jW

K_ ~ ±X— j/j± [_= %±j=j?/jW h 4 j= /> j_— W _ /_ !±~— /'j g ~XWj± , j/jK/~± _ / Bj±— X_>

Tg , B ' L ^J 8 %J±_Wj K_ ~ ±X— j/j ± [j±j ^=jW /~ = /^ W ° _?W j;_ ^ _ /j /'j /' ±jj — j/'~W=h

Q ?j — j/'~W /^ ±?jW ~ ^ / /~ >j % _ ±/XK^ _ ±° _W;_?/_Jj~^=h 4 ' X= — j/'~W '_= ?~ / / ±_ E

W X/X~ ? _ ° >jj? ^=jW !~± /'j g , B K_~±X— j/j±=h 4 ' X= [~±9 X= Wj=K±X>jW X? — ~±j Wj/_ X

msp


CH.-\PTER 8

SC.\L\L\RY AXD COXCLL"SIO:\S

In this thesis, several studies involving the energy measurement of particles us

ing calorimeters are presented. In Section -L ,. a study of the effects of radiation

damage on the response of a prototype for the Compact .\Iuon Solenoid (C.\IS) very

forward calorimeter is described. \\"e found that the effects of radiation damage on

the calorimeter·s response are dose dependent and that most of the damage will oc

cur in the first year of running at the Large Hadron Collider (LHC). Based on our

simulations. after 10 years of running, the energy resolution for 50 Ge\· photons will

be degraded by 103/c in the region of the detector that recei\·es the most radiation.

In Section G.-l. an evaluation of the performance of an algorithm called the Energy

Flow .\Iethod (EF.\I) is described. In this method. the information from the calorime

ter system is combined with that from a high-resolution charged-partide tracker in an

attempt to improve the energy resolution for jet mea:mrements. \\"e found that the

Energy Flow .\[ethod provides at best a 307c improvement in energy resolution for the

, energy measurement of jets. The improvement decreru;es at high energies where the

hadronic calorimeter resolution dominates the quality of the jet energy measurements

Both studies des~ribed above have been publishf'd ( or accepted for publication)

the the scientific literature. Reprints of these papers can be found in .-\ppendices .-\

and C. I played a crucial role in both studies.

The main emphasis of this thesis is on a study described m Chapters 5 and 7.

In Chapter 5, a study of three calibration methods for a longitudinally segmented

calorimeter was presented. Testbeam data from the Collider Detector at Fermila.b

(CDF) Plug Upgrade calorimeter were used to study and evaluate the three methods.

One method turned out to be particularly advantageous. This method has not tra

ditionally been used for the CDF calorimeters. This work is described in more detail

107

X? x % % j? W X] yh ['XK' X= _ ±j%±X? / ~ ! _ 7~ ^ ±? _ %^>XK_/X~? v [ ±~/j ~? /' X= /~%XKh 4 'X=

?j[ — j/' ~ W [_= _% % XjW /~ /'j g j ? /±_ g , B K_ ~ ±X— j/j± X? _ =j_±K' !~± '_W±~?XK

WjK_°= ~ ! /'j C1 _?W H >~=~?= X? /' j W X 7j / — _== =%jK/±^— Tg '_% /j± p'h x =XJ?_ ~ !

btpn„nbcsT=°=' „ mmns j;j? /= [_= !~ ^ ? W [ 'j? /' j ?j[ K_ X> ±_ /X~ ? — j /' ~ W [_= ^=jWh

4'X= K~±±j=%~?W= /~ _ K±~== =jK/X~^ q E o ° f B ' #l $ — N 1 ' f nchr „ m u ha T=° ='„ u hm T= /_ /'

?>h 4 ' X= ±j=^/ X= mhm = /_ ? W _ ±W W j; X_ /X~ ? = _±Jj± /' _? /'j Z /_ ? W _ ±W - ~Wj %±jWXK/X~?h

4 'j _±Jj =°=/j— _/XK ^ ? Kj ±/_ X? /° K~— j= !±~— /' j _K9 ~ ! %±jKX=X~? [ X/' ['XK' /'j

/±XJJj± j!!XKXj?K° X= 9?~[ ?h

4 'j =XJ?_ f B' ¥3 $ — N 1 =j±;j= _= _ ~?jE~!E_E9X?W K'jK9 ~? /'j 7j / j?j±J° =K_jh

ZX?Kj /' j 8N _?W ' >~=~?= '_;j %±jKX=j° 9?~[ ? —_==j=* /' j =XJ?_ =j±;j= _= _ ±j!j±E

j?Kj K_ X> ±_ /X~ ? =XJ?_ !~± /'j j?j±J° — j_=^ ±j— j? / ~! 7j /= X? /'j =_— j [_° /' _ / /'j

=XJ?_ ' #► —H—H =j±;j= _= _ ±j!j±j?Kj K _ X> ±_ /X~ ? =XJ?_ !~± /'j j?j±J° — j_=^±j— j?/

~! j jK /±~?=h 4'j ^ ? K j ±/_ X? /° ~! /'j 7 j / j?j±J° =K_j X= ~?j ~! /'j — ~=/ X— %~±/_? /

=~^±Kj= ~ ! =°=/j— _/XK ^ ? K j ±/_ X? /° X? W j /j ±— X? X? J /'j — _== ~ ! /'j /~% * ^ _ ±9 ~± ~! _?°

~ /' j± ?j[ %_±/XKj TjhJhh /' j qXJJ= >~=~ ? ' X? /'j QmmEmEA j1 ±_?Jjh

4 ' j Bj±— X_> 4 j; _ /±~ ? X= K^ ±±j? /° ±^ ? ? X? J [ X/' % ±~ /~ ? E_? /X% ±~ /~ ? K~X=X~?= _ /

Q : 1 f m hb r kj1h 6 X/' _ [jEWj=XJ?jW /± XJ J j ± * _ =j_±K' !~± /' j '_W±~?XK WjK_° ~! /'j

8N _? W H >~=~?= X? /' j W X7j / — _== = % j K /±^ — K~^W >j %j±!~±— jW X? ['XK' /' j /±XJJj± X=

!^° j!!XKXj?/ _ / ~[ W X7j / — _== ;_^j=h 4 ' X= [~^W ±jW^Kj /' j _±Jj =° = /j — _/XK j±±~±

%±j=j?/ X? /' X= =/^W°h Z^K' _ =XJ?_ K ~ ^ W * _= — j?/X~?jW _>~;j* =j±;j _= _ ^?X*^j

K'jK9 ~ ! /'j 7j / j?j±J° =K_jh v! /'j * ^ _ ? /X /° £ °• • El [bB ' { ■ o ° Q b ■' ¥P $ — N 1 { [_=

— j_=^ ±jW [ X/' J ±j_ /j± % ±jKX=X~? * X/ K~ ^ W _ =~ %±~;XWj _ K'jK9 ~ ! /'j Z /_ ? W _ ±W -~Wjh

mst


in Appendix 8. which is a reprint of a journal publication I wrote on this topic. This

new method was applied to the Central CDF calorimeter in a search for hadronic

decays of the \\' and Z bosons in the dijet mass spectrum (Chapter 7). A signal of

9873±3950(sys) ±ll:30 events was found when the new calibration method was used.

This corresponds to a cross section a· B(tr. Z -t jets) = 35.6 ± l-l.2(sys)±-Ll(stat)

nb. This result is 1. i standard deviations larger than the Standard .\Iodel prediction.

Tlw large systematic uncertainty comes from the lack of precision with which the

trigger efficiency is known.

The signal tr. Z -+ jet,; serves as a one-of-a-kind check on the jet enPrgy scale.

Since the tr and Z bosons have precisely known m,~SPS. the signal serves as a refer

encP calibration signal fur the energy measurement of jets in the same way that the

signal Z-+ c·t,- si•rves a .. -; a reference calibration signal for the energy IIH',l.!;llf('ment

of electrons. The uncertainty of the jt't energy seali• is on<' of tlw most imµortant

sources of systematic uncertainty in determining the m,l.!;S of the top quark or of any

othPr new particle (e.g .. the Higgs boson) in the lO!l-t:! e\" range.

The Fermilab Tevatron is currently running with proton-antiproton collisions at

J;; =l.96 Ge\'. \\"ith a \vell-designed trigger. a search for the hadroni<.: decay of the

tr and Z bosons in the dijet mass spectrum could be performed in which the trigger is

fully efficient at low dijet mass values. This would reduce the lar3e systematic error

present in this study. Such a signal could. as mentioned abO\·e. serve as a unique

check of the jet energy scale. If the quantity a(pp -, n·, Z) · B(ir, Z -r jets) was

measured with greater precision, it could also prO\·i<le a check of the Standard .\lode!.

108

l2li2r3tu4—w

DmV ' //% eii[ [ ;;EKW!h!?_hJO; iJ ±_ W = i/X% = i/' j = X=G /X% = h' /— F K W !% XK = h

DaV Z h, h q~—j= Bw 0 - v) x y Eg ~?!Etpimrs T^?%^> X='jW'h

DnV B h x >j —N q]BB 5 ^Kh v?=/h - j/'h x apm Tmbtt' ntph

DuV ,h x?]XWjX —N q]B■ 5^Kh v?=/h - j/' h x ncsh pn Tmbbu'e ,h x — XWjX —N q]BB 5^Kh

v? =/h - j/'h x nksh mnp Tmbbc'h

DcV 0h 6 XJ— _?=* 0j;h ZKXh v?=/±h rb Tmbbt' npanh

Dr7 0h 6 XJ— _?=h Oq]£0<S—N06 * D*—046 , —q1R0—S —*N <* kq0N<5]— k>61<51B v? /j ±E

? _ /X~ ? _ Zj±Xj= ~ ! - ~?~J±_%'= ~? L'°=XK=* ;~h msph Q ]!~±W v ♦?X;j±=X/° L ±j==h

Q ]!~±W Tasss'h

Dp7 0h 6 XJ— _?=h WqS •]<*4 5q]£0<S—N06B 5^Kh v? =/± h _?W - j/'h xh _±/XKj X? %±j==h

DtV 5h xK9K'^±X? —N q]B■ 5^Kh v?=/h - j/' h y mtp Tassa' rrh

DbV 5h x9K'^±X? —N q]B■ 5^Kh v?=/h - j/' h x nbb Tmbbp' asah

DmsV ,h x K~=/_ —N q]B■ 5^Kh v?=/h - j/' h y ra Tmbbm' mmrh

DmmV g , B g ~ _>~±_ /X~? h ">— O y z [ [ "—5>*<5q] y—1<4* I—•£0N■ Bj±— X_> v? /j ±? _

0 j % ~ ±/ brinbsEw T^?%^>X='jW'h

DmaV Q h k _?j _?W 0h 6 XJ— _?=* 5^Kh v? =/±h _? W - j/'h x usb Tmbbt' ramh

DmnV 0h 6 XJ— _?=* 5^Kh v?=/±h _?W - j/' h x acb Tmbtp' ntbh

DmuV 4 hx h k _>±Xj* —N q]B■ 5^Kh v? =/±h _? W - j/'h x nnt Tmbbu' nnrh

DmcV Qh k _?j _?W 0h 6 XJ— _?=* 5^Kh v? =/±h _ ? W - j/' h x nrc Tmbbc' msuh

msb


BIB LI OG R.-\P HY

[1] http://www-cdf.fnal.gov/grads/tips/thesis_tips.html#cdfpics.

(2] S.D. Holmes FER.\IIL.-\B-Conf-87 /160 (unpublished).

[3j F . .-\be et al., .\"ucl. Inst. .\leth .. -\ 271 (1988) 387.

[-l] D. Amidei et al. . .\"ucl. Inst. .\Ieth . .-\ 350. 73 ( 199-l): D. Amidei et al.. .\"ucl.

Inst. .\Ieth . .-\ :360. t:3, (1995).

[5] R. \\"igmans, Rev. Sci. Instr. 69 ( H)98) 372:3.

[6] R. \\"igmans. Calorimdry · Energy Mms1Lrf'.me11t in Particle Phy8ic:;. Inter

national Series of .\[unographs on Physics. vol. 10,. Oxford l·uiversity Press.

Oxford (2000).

[,] R. \\"igmans. StJ.mplin!J calorimetnJ . .\"ucl. Instr. and .\Ieth . .-\. articl1) in press.

[8] .\" . .-\ckchurin et al., .\"ud. Inst. .\Ieth. B 187 (2002) 66.

[9] .\" . .-\kchuriu et al., .\"ucl. Inst . .\Ieth .. .\ 399 (199,) 202.

(10] D. Acosta et al., .\"ucl. Inst . .\[eth. B 62 (1991) 116.

[11] CDF Collaboration, The GDF II Technical Design Report, Fermilab Internal

Report 96/390-E (unpublished).

[12] 0. Gane! and R. \Vigrnans, .\"ucl. Instr. and .\leth .. .\ -109 (1998) 621.

(13] R. \Vigmans, ::'\ucl. Instr. and .\Ieth . .-\ 259 (1987) 389.

[1-1] T.A. Gabriel, et al., Nucl. Instr. and .\Ieth . .-\ 338 (1994) 336.

[15] 0. Gane! and R. \Vigrnans, Nucl. Instr. and :\Ieth .. -\ 365 (1995) 10-1.

109

Dmr7 Zh y j'±j?W=* - h,h Z'_%X±~h wh L_±j* W<*4]— k <£* I—1•£*1— <* N>— O—*N0q]

Oq]£0<S—N—0B g , B P~/j msrr Tmbtb'h

DmpV -h x >±~[ h —N q]BB 5^Kh v? =/± h _?W - j/'h x utp Tassa' ntmh

DmtV kh q _?=~?* —N q]B■ L'°=h 0j;h ) j//h nch mrsb Tmbpc'h

DmbV , hLh y _±> j± —N q]BB L'°=h 0 j;h )j//h unh tns Tmbpb'h

DasV 8xa g ~_> hh -h y _??j± —N q]BB L'°=h ) j //h mmtyh asn Tmbta'h

DamV kh , ±j[ = —N q]BB 5^Kh v?=/±h _?W - j/'h x abs Tmbbs' nnch

DaaV Qh ) ~>>_? h xh Z ±X'_±_? h 0h 6 XJ— _?=h 5^Kh v?=/±h _? W - j/'h x ubc Tassa'

msph

DanV 5h wWW°* —N q]BB NQ >=j±;_/X~? ~! q _W±~?XK 8 & ,jK_°= X? N N w;j?/=hN

g , B ix 5 x ) i4 Q L ig , B 0 in s t r Tmbbc'h

0h 6 X9 X?=~? _?W 0h q~j>jj9* ®q _W±~?XK vB ,jK_°= X? 9 4_JJjW 4 ~% g _?WXE

W _ /j= hN g , B ix 5 x ) i4 Q L ig , B 0 in m n r Tmbbc'e N8 % W _ /j /~ q _W±~?XK v4 ,jE

K_°= X? 9 4_JJjW 4~% g _? W XW _ /j= h♦♦ g , B ix 5 ) i4 Q L ig , B 0 in c u n Tmbbr'h

Zh x ~ /_ * Zh ( X— * _?W (h ( ~?W~h Nx 8 ♦ — _== %j_9 X? W X7j / X?;_±X_? / —_==

W X= /± X> ^ /X~ ? !~± q AE ! uE7j/ j;j?/=*£ g , B ix 5 x ) i4 Q L ig , B 0 in s n u Tmbbc'e

N8 % W _ /j ~? _ Qb — _== %j_9 X? W X7j / X?;_±X_? / — _== W X= /± X> ^ /X~ ? !~± Qb P 3 uE

7j / j;j? /=h£ g , B ix 5 x ) i4 Q L ig , B 0 in a n c Tmbbr'h

DauV 4h , ~±XJ~ —N q]B■ NQ >=j±;_/X~? ~ ! ' ,jK_°= /~ 9 3 ^ _±9 L _ X±= X? /'j v?K^=X;j

- ^~? , _ /_ =j /*£ g , B ix 5 x ) iw 6 ( ig , B 0 iu n a s Tmbbp'h

DacV )h k _ /Xj ±X —N q]B■ Nzj / k" =° =/j— _/XK= = /^ W Xj = ^=X?J /' j ' P 3 m 7j / =_— % j *£

g , B iL q 2 Z i4 Q L ig , B 0 in u b b Tmbbp'h

mms


[16) S. Behrends, .\LO. Shapiro. E. Pare, Single Pion Response in the Central

Calorimeter. CDF .\'ote 1066 (1989).

[l i] :\I. .-\lbrow. et al., ~ucl. Instr. and ~Ieth . .-\ -18, (2002) 381.

[18] G. Hanson, et al., Phys. Rev. Lett. 35. 1609 (1975 ).

[19] D.P. Barber et al., Phys. Rev. Lett. 43. 830 ( 19,9).

[20] C.-\2 Collab .. .\I. Banner et al .. Phys. Lett. 1188. 203 ( 1982).

[21] G. Drews et al.. .\'ud. Instr. and .\Icth .. -\ 290 (1990) 335.

[22] 0. Lobban .. -\. Sriharan. R. \\"igmans . .\'ucl. Instr. and .\Icth .. -\ -195 (2002)

107.

[2:3] .\'. Eddy. et al.. ··Observation of Hadronic n· OPcays m tl Events:·

CDF /.-\.\'.-\L/TOP /CDFR/3086 (l!J95).

R. \\'ilkinson and R. Hollebeek. ·'Hadronic n· Decays in b Tagged Top Candi

dates." CDF / .-\.\'.-\L/TOP /CDFR/3136 ( 1995): ··Cp<late to Hadronic n· De

cays in b Tagged Top Candidates,"' CDF /.-\.\'L/TOP /CDFR/35-13 (1996).

S .. -\ota., S. Kim, and K. Kondo. '·.-\ i r mass peak in dijet invariant mass

distribution for n· + -!-jet events," CDF /.-\.\'.-\L/TOP /CDFR/303-l (1995):

··Cpdate on a iv mass peak in dijet invariant mass distribution for ir + 2: 4-

jet events," CDF /.-\:\".-\L/TOP /CDFR/3235 (1996).

[2-l] T. Dorigo et al., '·Observation of Z Decays to b Quark Pairs in the Inclusive

.\luon Dataset, .. CDF /AN.-\L/E\\'K/CDFR/-1320 (1997).

[25] L. Galtieri et al., ··Jet Pr systematics studies using the Z + 2: 1 jet sample,"

CDF /PHYS/TOP /CDFR/3-199 (1997).

110

DarV Zh ( X— _?W Zh 1Aj7KX9h Nzj/ "2 ZK_j !±~— - ~— j?/^— y __?KX?J X? ' S m zj /

_?W L '~ /~? E! ) z j / hN g , B ix P x ) i4 Q L ig , B 0 in c s u Tmbbr'h

DapV )h k _/Xj ±X _?W z h )°=h ®q~[ [j W~ [j ^?Wj±=/_?W 7j /= X? 0 ^ ? v. Z /^W° ~ ! /'j

z j / w ?j±J° ZK_j !~± 0_[ zj / D " 3 t kj1hN g , B ix 5 x ) i4 Q L ig , B 0 in b t n

Tmbbp'h

DatV 0h 6 X9X?=~?h 0h q ~j>jj9h 6 h 6 j=/j±h NZj_±K' !~± /'j q _W±~? XK ,jK_°=

f \ ' F #l $ — N $ — N 8 =X?J v?K^=X;j , X7j/= X? 0^? vghN

g , B ix P x ) izw 4 ig , B 0 iu m b m Tmbbp'h

Dabm hzh x X//X :<N q]BB Hh L'°=h g EL _±/XK j= _?W BXjW= ubh mp Tmbbm'h

DnsV Bh x >jh —N q]BB L '°=h 0j;h ) j //h prh nsps Tmbbr'h

DnmV z h , X//— _? ? h N- j_=^±j— j?/ ~ ! /' j 8E!E l m zj / g ±~== ZjK/X~? X?

L ±~ /~ ? Ex ? /X% ±~ /~ ? g~X=X~?= _ / Q : 1 m mht 4j1hN L ', , X==j±/_ /X~? h ,^9j

8 ?X;j±=X/°h mbbth

DnaV Zh q _^Jj±h N- j_=^±j— j?/ ~ ! /' j H “ #l■ — "—H E! h1 zj / g±~== ZjK/X~?= X? ••

g~X=X~?= _ / 1 \1 f mht 4j1hN L ' , , X==j±/_/X~? h , ^9j 8 ?X;j±=X/°* mbbch

DnnV )h ( jj>j _?W yh B _^J'j±* NPj[ z j / g ~±±jK/X~? B^?K/X~? 3 , zZ g Q a hs i♦

ig , B ix 5 x ) iz w 4 ig , B 0 im c m n Tmbbm'h

DnuV g , B ?~/j= ctnh msrr* matrh mnuu* atnt* crssh

DncV Qh ) ~>>_?* 0h 6 XJ— _?=* Ng _ X> ±_ /X~ ? ~ ! /'j g j ? /±_ K_ ~ ±X— j/j± ^=X?J 0 ^ ? v

— X? X— ^— >X_= W _ /_ *N g , B i, Q g ig x ) Q 0 v- w 4 0 2 iL 8 y ) vg ic t u t Tassa'h

DnrV Q h ) ~>>_? * 0h 6 XJ— _?=* N v? /j ±K_ X> ±_ /X~ ? ~! /'j j— _?W ' _W =jK/X~?= ~ ! /' j

L ^ J 8 %J±_Wj g _~ ±X— j/j±e L _ ± / v v *£

g , B i, Q g ig x ) Q 0 v- w 4 0 2 iL 8 y ) vg ic c t r Tassm'h

2 > >


[26] S. Kim and S. Vejcik. ".Jet Er Scale from .\Iomentum Balancing in Z + 1 Jet

and Photon+l .Jet.'· CDF/.-\~ . .\L/TOP/CDFR/350-1 (1996).

[27] L. Galtieri and .J. Lys. ·'How well do we understand jets in Run I'? Study of the

.Jet Energy Scale for Raw .Jet Er 2: 8 Ge\ . .'' CDF /A.\" . .\L/TOP /CDFR/3983

( 1997).

[28] R. \\.ilkinson. R. Hollebeek. \\·. \\·ester, ··Search for the Hadronic Decays

Jr/ zo -t jetjet Csing Inclusive Dijets in Run re:· CDF / . .\:'\ . .\L/ JET /CDFR/-1191 (1997).

[29] .J. Alitti d al .. Z. Phys. C-Particles and Fields -19. l 7 ( 1991).

[30] F. Abe. d al .. Phys. Rev. Lett. 76. 3070 (1996).

[:31] .J. Dittmann. ··.\leasurement of the 11 ·-+- 2: 1 .Jet Cross Section in

Proton-. .\ntiprotun Collisions at -./s = 1.8 Te\·:· PhD Dissertation. Duke

Cniversity. 1!)98.

[32] S. Hauger. ··.\Ieasurement of the zo -t e..-e- + X .Jet Cross Sections in pp

Collisions at fa= 1.8 Te\·_-, PhD Dissertation. Duke Cniversity, 1!)95.

[33] L. Keeble and B. Flaugher. --~e,,,. . .Jet Correction Function QD.JSCO 2.0,''

/CDF /A:'\ . .\L/.JET /CDFR/1513 ( 1991).

[3-t] CDF notes 583. 1066, 1286, 13-1-1, 2838, 5600.

[35] 0. Lobban, R. \Vigmans. ··Calibration of the Central calorimeter using Run I

minimum bias data," CDF /DOC/CALORI.\IETRY/PUBLICj.:58-18 (2002).

[36] 0. Lobban, R. \\.igmans, ··Intercalibration of the em and had sections of the

Plug Gpgrade Calorimeter: Part IL"

CDF /DOC/CALORL\IETRY/PGBLIC/5586 (2001).

111

x L L w P , v5 x

vP 4 w 0 g x ) vy 0 x 4 vQ P Q B 4 q w ) Q P k v4 8 , vP x ) Zw k - w P 4 Z Q B x

g x ) Q 0 v- w 4 w 0 Z2 Z4w- T0 w L 0 vP 4 w , 6 v4 q Lw 0 - vZZvQ P B0Q -

P 8 g ) w x 0 vP Z4 0 8 - w P 4 Z x P , - w 4 q Q , Zh xutp Tassa' ntm'

FFE


.-\PPE:\"DIX .-\

I:\"TERC.-\LfBR.-\TIO:\" OF THE LO~GfTCDf:\".-\L SEG~IE:\"TS OF :\

C.-\LORD.IETER SYSTE.\l (REPRI:\"TED \\"ITH PER.\IISSIO?\ FRO~l

:\"L"CLE.-\R IXSTRC.\IE:\"TS .-\~D .\IETHODS, .-\-!Si (2002) 381)

112

lw ) Z w 1 v w 0 P ^ K j _ ± v? = /±^ — j ? /= _ ? W - j /' ~ W = /? L ' ° = XK = 0 j =j _ ±K ' y vZ . s s a ' r r Ep n

CCZ ?/[-/X=— [ //9 - _ 8 !X_ = ' x - 0

[[[hK8K; j±hK^/?i/KK?K! _/— >

5""ky■’ ^ " ]cJpc■p^* c*J ■,kp] y^*’k<£k*yk’ "^] ■,k •k]"^]¥c*yk ^ " ■,k "^]Wc]J yc>^]p¥k■k]’ p* ■,k 6n h kH•k]p¥k*■

Ph x9K'^±X? _h xhZh x;_? >h k°h)h yj?K\j K* vh ,^—_?~J^ Wh wh w=9^/ Whxh Bj?°;j=X Kh xh Bj±±_?W~ ±h 1h k_;±X~; =* gh q^7W^ Kh -h) z~=_ !h xh (_°X= Wh 1h (~~=~; Uh Zh (^j='~; Jh xh (^\^KÊL~_/~\ Wh ,h )XX;X?/=j; Jh Qh )~>>_? zh zhELh -j±~ >h zh -~?_± Kh 2h Q?j >h kh Q?j?JXX/ Wh ,h Q=>~±?j 'h Ph Q\WjOE(~K_ Wh

1h Z/~X? =h )h Z^_9 'h xh 8°_?~; =h Zh 8\^?X_? =h kh 1j=\/j±J~—>X 0h 6XJ—_?= _&C ,h 6X?? xh 2^—_='j; Lh H__? Kh C h Hj°±j9 zUm

U "—B<qBh "N p \R0—0R ]N pR9N'B=vB [ W B< U )A—±j±=XX° , ]RRqB !d— /AXX;h pZW v

a [a < I QNa ]B o<R<R•5RB ::R*HN<1'z ] R <<_ 0R * dB*R<■ "R0v—6

B["c,a.B y0 :<:N——*B iieUie +^±; . O ! "B ,<R]*E W•0R<N

. :" Nk B hi_^ X— h :<nSS oR<N£* pZNR00*R6B oN*<R*B pLW BN

& zq<0:d—d< pZ*NN50R]_ zR<0:<5d pZWBN

0 jKjWjW an z^?j a/'Q

x >- — K!

4 'j j]%j±X— j?/= _ / /'j )_±Jj q_W±~? g ~XWj± T)q g' [X '_;j /~ Wj_ [ X/' ^?%±jKjWj?/jW ±_W X_ /X~? ~j = h v? /'j _±JjE±_%XWX/° ±jJX~?Uh K~=j /~ /'j >j_— %X%j* /'j=j ~ W = ±j_K' —jJ_ J ±_°= % j ± °j_±h 4'j Wj/jK/~ ±= /~ 'j X?=/_jW X? /'j=j ±jJX~?=* /'j q B g~~±X— j/j±=* _±K Wj^J?KW /~ ~%j±_/j ^?Wj± /'j=j K~?W X/X~?=h v? /'X= %_%j±* [j Wj=K±X>j T'j ±j=^/= ~ ! =/^WXj= X? ['XK' _ % ±~ /~ /°%j K_~±X— j/j± [ _= j]%~=jW /~ ±_WX_/X~? ~ ! /' j /°%j _?W X?/j?=X/° j]%jK/jW _ / /'j )qgh 4'j=j =/^WXj= — _Wj X/ %~==X>j /~ j=/X—_/j /'j j!!jK/= ~ ! /' X= ±_WX_/X~? ~? /' j ±j=%~?=j _~W /'j ±j=~^/X~? ~ ! /'j K_E~ ±X— j/j ± _= _ !^?K/X~? ~ ! /X—j W^±X?J )q g ~%j±_ /X~? h ■" assa w=j;Xj± ZKXj?Kj yh1h x ±XJ'/= ±j=j±;jWh

g~±±j=%~?WX?J _^/'~±h gK) {©XEOsXlpuaEnp.bo !_]h {UmEtsrE puaEm vZ ah

D**RNN< <RN<<0—<<n [ X J — _ ? ° ^ / / ^ hj W ^ X0 h 6 /J — _ ? U Xm Q ? j _ ; j ~ ! _ ' ! /K ? K K h L j ±— _ ? j ? / x W W ±j== - XW W j w _= /

4 j K ' ? XK _ 8 ? X; j ±= X/° h x ? 9 _ ± _ h 4 ^ ±9 j ° h

Ih v?/±~W^K/X~?

, j /jK /~ ±= X? j] % j±X— j? /= _ / /' j !^ /^ ±j ) _±Jj q _ W ±~ ? g ~ XW j ± T) q g ' [X ' _ ; j /~ ~ % j ±_ /j _ / ±_ W X_ /X~ ? j ; j = /' _ / _ ±j K ~ ? = XW j ±_ > ° ' XJ'j± /' _ ? X? j ~ XW X? J E> j _ — j] % j± X— j ? /= _ / ~ [ j± K j? /j±E~ !E ±?_== j ? j ±J Xj = h w =% jK X_ ° X? /' j !~ ±[ _ ±W ±jJ X~? * _ /

svrZEcZn5isaiZ ■ =jK g±~_/ — _//j± g a6'a g'j=/j± Z ~K?KK yh1h xq ?J'^ ±j=j±;jWh mUmme Z s m r t E c n n h C ’s m ' s s c c a E .

mmn


ELSEVIER

Effects of radiation and their consequences for the performance of the forward calorimeters in the Cl\tlS experiment

N. Akchurin ". A.S. Ayan b. Gy.L. Beneze C. I. Dumanoglu J. E. Eskut J.

A. Fenyvt.-si c;. A. Ferrando r. V. Gavrilov .:, C. Hajdu ..:. M.I. Josa r. A. Kayis 0•

V. Kolosov ~. S. Kulcshov g_ A. Kuzucu-Polatoz J_ D. Litvintsev ~. 0. Lobban". J.-P. ~krlo b. J. Molnar\ Y. Ond b. G. Onengilt J. D. Osb\.1rnc h_ N. Ozdc~-KlX.-a J_

V. Stolin .:. L. Sulak h. A. lilyanov g. S. Uzunian g. G. Vcsztcrgombi '. R. Wigmans a.•. D. Winn;_ A. Yumashcv !\ P. Ztlan C. M. Zcyrek "· 1

• Tc.,u., r~d, t ,ur~r,ur UINtt..ic-t. ( ~"i.4 • Cnn·..-r,:1h· ,tf lo"'"· fo"u Cio·. LS. t • KFKI R .II l(f. &.lupnt. llu~,:ur•

"' ~ ·uii."r.,r(J l"nn~·run· l,J,u,.,. Tur4. .. ·~ ' . I TU.\/ JC/. Drtm,w,. 11:.n,:,,n·

' CU:.lt. IT. .\luJn.J. Spuu1 I ffJ;"P . . \/u1c.u11. H.:&.l.114'

ll /wJll.lf1 Cm~r,ur. 801.1"11. L'S. I

· Futr/wld C,uurut1·. Fatrhd.J CS. I

The ~p(rimc:nb al th.: L.ir~ Hadron C"lhJ.:r I LHCI wtll ha,·( 1-, Ji::,I with unpr.:.:alc:ntai r.u!ia1100 1,:-,d,. In th.: large-r.ipiJiry rrgion<. di,-cc; lo the b.::un pipe;. thoc: t.:-.d, n::u:h mqr-sgra~, per ~c:-.tr. Tb.: ,kt.:.."t,>r• lo h.: ilbt.1ih:d in the:..: ri:g1011.>. the Hie: Calorirnct.:n.. .in: d.:sti;nai to opc;r.uc untlcr th,:,,c ,-unwuons. In rhb pap,:r. "'" Jes.:nb,: lb.: roulu of ,rnJic:1 in "h1.:h a prutolyp.: .alorillld.:r 1>1as c:.~l'O"'C(I 10 radiation -,f rhc l}P.: .snJ inr::n. ... 1y i:xpc,:lctl al the LHC. Thoe: ,1uJ1,-s =J.: ll pos,1blc; lo oti=rc the dli:,:u of thi~ r.stfui11on on th.: n:spon,c; and the rooluuon .,,. th.: ,-:ilorimclcr a\ a fun.:uon of rime during LHC or,:ration. ·e :!00~ Elsevier Sai:no:c B. V. All rights re><:ncJ.

• C<>rropun.im11 authur. r.:.L •l-11~~-'Z-Ji7>: fa.'l. •1~'11>6-;4:.1 l.~l.

E.--,,..,,J <t,J.fr.-u: "lJ;m.lJ1>/!<111L.:ilu IR. \V-rgman,,1

' On lcn•c u( ~i..:"'"'· P.rman..-nr ,.JJh!S,\; :1.1,Jdk E.i>I T ,,.:111111:.il lJ 111,1:r>lly. Ank.ir.&. T urk,-y.

I. Introduction

Detc:ctors in c:.~po:rim.:nL~ al the future Large Hadron Collidcr (LHC) will haw to op,:r.11<: at r..tdiation kvds that an: consiJ(T;lbly high,:r than in colliding-beam ap,:rimcnts at lower a:ntc:r..:ifmas:. cn.:rgics. Esp,:cially in th.: forward region. al

0168-5UXIO::tS. ,._.., front m.atter C ::00~ IJ.c>:.:r s.:i._.,..-.: 8. \'. All n;;hl.l. rcs.,r,C\l

PII: S0l6S-HJ.X1011ooss:-7

113

h1 }v0NNR0N* 0N N<] ( x 6 [*$<0 N^ E BdNNEN qN k>61 :d € N < ()Z ZjVVj Z O'6*rM Vo

% =j^ W ~ ±_% XW X/Xj = ABS c n Er h /' j =j ±_W X_ /X~ ? j;j= ±j_K' _ W ~ — _ X? /' _ / ' _ = ±j— _ X? j W _? ^ ? K ' _± /j W /j ± ± X /~ ±° — %_ ±/XK j % '°=XK= j]%j±X— j? /= ^% /~ ?~[ E v #ms 1 !g ° X= j]%jK/jW /~ > j _KK^ — ^ _ /jW W ^ ±X? J ms ° j _ ±= ~ ! ) q g ~ % j ±_ /X~ ? _ / W j=XJ? ^— X?~=X/° X? /' X= ±jJ X~ ? h

Q > ; X~ ^ = ° * /'j W j =XJ ? ~ ! W j /jK /~ ±= /~ >j X? E= /_ jW X? /' X= ±jJ X~? X= /X±= / _ ? W !~ ±j— ~=/ J^ XWjW >° /'j ? jKj==X/° /~ =^ ±; X;j X? /'j=j ' _ ±=' K ~ ? W X/X~ ? = h 4 ' j g - Z j]%j±X— j? / Dm ’ ' _ = K' ~ =j? _ K _ ~ ±X— j /j ± >_=jW ~ ? * ^ _ ± / i X>j±= _ = _ K /X; j — _/j±X_I !~ ± /' j 'XJ'EX' ±jJ X~ ? = h q XJ ' E% ^ ? /° * ^ _ ± /\ X= 9?~[ ? /~ >j ±_ W X_ /X~ ? E' _ ±W DnV*

v? % ±j ; X~ ^ = % ^ > XK _ /X~ ? = * [ j '_;j ='~[ ? /' _ / /' X= /° % j ~ ! K_~ ±X— j /j ±* _ /' ~ ^ J ' % ±X— _±X° K' ~ =j? > jK_^ =j ~ ! X /= j]%jK/jW K _ % _ > XX/° /~ ~ % j ±_ /j ^ ? W j ± /'j=j W X!XK^ / K X±K^ — =/_? Kj=* %~==j==j= =~— j ;j±° =%jKX!XK % ±~ % j ±/Xj = /' _ / _ ±j j] /±j— j° ;_ ^_> j !~ ± K _ ~ ±X— j /±° _ / 'XJ'E±% [ ' j ±j /'j %_±/XK j Wj?=X/° X= ;j±° ' XJ ' X? !! j]% j±X— j? /=e ^ /±_ !_ = / =XJ?_= _ ? W ;j±° ? _ ±±~ [ _ /j ±_ =' ~ [ j ± %±~!Xj=h 4 'j=j % ±~ % Ej±/Xj= _ ± j _ W X±jK / K~ ? =j* ^ j? Kj ~ ! /'j !_K/ /' _ / /' j = XJ?_= X? /'^= K _ ~ ±X— j /j ± K~ ? =X= / ~ ! g j±K? 9 ~ ; XJ' /* % ± X— _ ± X° % ±~ W ^ K j W >° /' j j jK/±~?= _ ? W % ~ = X/±~ ? = !±~ — X!♦E— W^KjW j jK /±~ — _J ? j /XK =' ~ [ j± K ~ — % ~ ? j ? /= DnhuV*

v? /' X= % _ % j ± * [j ±j % ~ ±/ /' j ±j=^/= ~ ! _ W j W XEK _ /jW = /^ W ° ~ ! /' j ±_ W X_ /X~ ? j!!jK/=* X? [ 'XK' [j !~K^=jW ~ ^ ± _ //j ? /X~ ? % ±X— _ ± X° ~? /'j b’Y(2L Xi^j— ;= ~ ! WjJ ±_W jW ~ % /XK _ * ^ _ X/° !~ ± ±j j;_? / K _ ~ ±X— j /± XK % ±~ % j ±/Xj= =^ K' _ = /' j K _ ~ ±X— j /j ± ±jE=%~?=j /~ ='~[ j±X?J % _ ±/XK j = ~ ! _ JX;j? j?j±J° _ ? W /' j j ? j ±J ° ±j =~ ^ /X~ ? [ X/' [ 'XK' =^K' % _ ± / X EK j= K _ ? >j W j /jK /j W >° /' X= K_~ ±X— j /j ±h B ~ ± /' j=j ±j_ =~ ? = * [ j X±±_ W X_ /j W _ ? j ? /X±j K _ ~ ±X— j /j ± — ~ W E^j [ X/' % _ ±/XK j = ~ ! /' j /° % j ±j=%~?=X> j !~ ± — ~=/ ~ ! /' j _ > = ~ ± > j W ±_ W X_ /X~ ? W ~ = j = _ / ) q g h

4 'j % _ % j ± X= ~ ±J _? X\jW _ = !~ ~[ =h v? ZjK /X~? ah /'j K _ ~ ± X— j /j ± ^ =jW X? /' X= = /^ W ° * /'j X±±_W X_ /X~ ? /~ [ ' XK ' X/ [ _= =^> 7jK /jW * _ ? W /' j — j_=^ ±j— j? /= K _ ± ±Xj W ~ ^ / /~ _==j== /'j j!!jK/= ~ ! /' X= ±_W X_ /X~ ? _ ±j W j=K ±X> jW h v? ZjK/X~? n* [ j % ±j =j? / /'j j] % j±XE— j? /_ K _ ~ ± X— j /j ± W _ /_ _ ? W /' j ±_ W X_ /X~ ? W ~ =j % ±~!Xj=h 4 ' j =j W _ /_ _ ±j X? /j ±% ±j /j W — /'j K~ ? /j] / ~ ! _ = X— % j — ~ W j /' _ / W j =K ±X> j = /' j j!!jK/= ~ ! X? EK ±j_=jW XJ ' / _ //j ? ^ _ /X~ ? X? /' j * ^ _ ± /\ !X>j±= X? /j ±— = ~ ! _ % _ ±_ — j /j ± ’\ ' /' _ / [ _= !X±=/ X? /±~ W ^ KjW X? ± _ W X_ /X~ ? ' _ ±W ? j== = /^ W Xj = ~ ! =K X? X_ /~ ±E>_=KW

%_±/XK j W j /j K /~ ± = h v? Z jK /X~? u h _ - ~ ? /j g _±~ = /^W° X= W j =K ± X> j W /' _ / = X— ^ _ /j= /' j j]%j±X— j?E/_° ~>=j±; j W j!!jK/= _? W % ±j W XK /= /' j X± X— %_K/ ~? /'j K _ ~ ± X— j /j ± % j ±!~ ±— _? K j W ^ ± X? J ) q g ~ % j ±_ E/X~?h g ~ ? K ^ = X~ ? = _ ±j ±X; j? X? Z jK /X~ ? nh

) Tj]%j±X—j?/_ =j/^%

ah ih Ex2 '*2V2b^„;

4 ' j K _ ~ ± X— j /j ± ^=jW !~ ± /' j = /^ W Xj = Wj=K±X>jW X? /' X= % _ % j ± K~ ? =X= /jW ~ ! /' X? * ^ _ ± / i X>j±= j— E>jWWjW — _ K ~ % % j ± — _/±X] h 4 ' j !X>j±= [ j±j ~ ±XEj? /jW _ ~ ? J /' j W X±j K /X~ ? /±_; j jW >° /' j X?K~— X?J %_±/XKj=h 4 ' j =' ~ [ j±X? J % _ ±/XK j = J j ? j±_ /jW gj±E j?9~; XJ ' / X? /' j !X>j±=h L ' ~ /~ ? = j— X//jW [ X/'X? /'j ? ^ — j ±XK _ _ % j ± /^ ±j ~ ! /' j !X>j±= [ j±j K_% /^ ±jW _?W / ±_ ? = % ~ ± /j W /' ±~ ^ J ' X? /j ±? _ ±j!jK /X~? /~ /'j X>j± j ? W = * [ ' j ±j /'j° [ j±j K ^ ? ; j ± /j W X? /~ %'~ /~ E j jK/±~?= X? /' j % ' ~ /X AK _ /' ~ W j ~ ! _ % ' ~ /~ — ^ /X% Xj ± /^>j TL - 4 'h 4 ' j W XJ X/X\jW ~ ^ /% ^ / ~ ! /'j=j L- 4= K~ — % ±X=jW /' j K _ ~ ±X— j /j ± =XJ?_=h

4 'j * ^ _ ± /\ X>j±= K~?=X= /jW ~ ! _ s hns — — W XE_— j /j ± K ~ ±j =^ ±±~ ^ ? W j W >° s hsmc — — /' XK9 K _W EWX?Jh 4 Xj X> j ±= [ j±j _ ± ±_ ? J j W X? _ 'j]_J~?_ = /±^ K /^ ±j * j _ K ' !X>j± j* ^ XW X= /_? / Ta hn — — !±~— X/=

——g^ _>=~±>j± %_/j

Y a m m h r —— #»o

tk J* £■ ■ Wk]’

j

Q~~±/\ !X>j±=

b TMl vh 4 ' j /~ [ j ± = / ± ^ K /^ ± j ~ X /' j K _ ~ ± X— j /j ± h 4 ' j /_ =j / ='~[ = /' j % ~ = X/X~ ? X? J ~ / / ' j * ^ _ ± /U / > j ? h

mmu


pseudorapiditics :'Ii ~ 3---6. these r:idiatil.'n levels reach a dolllaln that ha.s n:mamcd an unchancd territory in panidc physics expcrimc:nl5 up 10 now: I-IO ~Gy is c:xpcct~-J 10 be acrumulat(<l during IO yi:ars of LHC opcr.uion at d~ign luminosity in the. region.

Obviously. the: d.:si~"ll of dc:lc:\."tors 10 be installed in this region is first and foremost guided by th,: nc:\.'l.-ssi1y lo sur,.i,·c: in thoc: h:lrsh conditions. Tb: C\lS l!'tp,:nmc:nt ( I ( has chosen a c-,ilorimc:tc:r basc:tl on qu.111.t tib,:rs a.~ acti\,: malc:nal fur th,: high-17 rc:giora. High-punty quartz LS known to b.: r.idiation-hanl [.:?].

In pr • .,,ious public-.iuons. we: ha,e shown that this type of \.-alorimdc:r. although primanly chosen bc:caus.: of 11.'i .:lp,:ct.:d .:apabili1y 10 opcralc ur.dc:r lh•-..: ditlicuh cin.:umslan'--..-,i, pus.=-s some \,:ry SPc:\.,tic prop,:n1.-s that an: c:.llrc:mdy \·aluablc: for .-alorimc:lry .11 high.,,. "hcn: th,: p-.irudc: d.:n~it) is ,c:ry high in pp .:,pcnm.:nts: ultrafast signals and ,cry narrow lat.:ral ,h,mcr prntik-s. TI1a-,,.: propc:rt1c:s an.· a Jirc,,:t conscquc:11"-c: of the: fact that ti:,: ,ign;tls m tl~L, •-:ilonm.:tcr c,,nsist .if C.:n::nk,,.,litdtt. pnmarily protlu.:cd by th.: c:k,:1runs a1:d positrons from :r' -mdU\.'\.-J ,:k:ctromagnc:uc sl:ow.:r ,:omp,mc:nu [3.4].

lit this p:.ip,:r, w.: report the r.-sults of a dL-Ji\."al(<l study of lhc radiation dfoc1s. in which 111c focus.:d our .iuc:ntion primanly on the: cun.st'q11err,·<'s of dcgrad.-J ,>pl io.:al quality ti.,r rdcvam • .ilorimc:tric propc:rt1c:s such as the calorimctc:r rc:,ponsc to sho\\c:ring parudcs of a gi,cn ,:ncrgy and the c:n.:rgy resolution with which such p-artid~ can be dcll!\:IL'\J by lhu ..:alorim.:tcr. For ti1csc n:-.uons. we irradiat.:d an entire: calorimctc:r moJulc: "';lh parti.:b of th.: typo: n:,,ponsibl,: for mo~t of th,: absorbed radiation dose. at LHC.

The: paper is organued as follows. In Section 2.. 1h.: calorim,:tc:r USc:d in this >tudy. the: irr.idiation to which 11 was subj.:ctc:J. and th,: mc:asurc:mc:nts carried out lo ~ the: ,:tTc:cts of this radiation arc dc::icribcd. In Section 3, we: pn:scnt the c:.tpcrim..:111al \.-alorimct,:r Jal.i and the r:.idialion dos.: prolilc:s. Thc:sc: data arc int,:rprc:tc:d in the .:onlc:.,:t of a simple mood that dc:sc.Tibc:s the: ctfc:,:t:1 of incrcasc:d light a1tcnua1ion in the quartz tillers in terms of a p-.iramc:tc:r Ii) that was first intro<lu~'l:li in radiation hardness studies of scintilla1or-ba.scJ

11--1

1>7

particle detectors. In S..-,.-i1on -l. a '.\lonte Carlo study is d.:scnbc:d that simulates the apcrimcn-1ally obsc:rn:d c:tfocts and prt:dicts their impact on th,: L-,lloriim:tc:r p.:rforman~,: during LHC opcr.ilioo. C.:indusions arc tti\c:n in S.:Ctiun 5.

2. r.~~rimrnt:al "idup

:!.. I. n, •. ,l.:u:ctvr

The o:.ilurimclcr used for lhc studiL"S d.:S\:nh..-J in this pap,:r L-UnsistL-J uf thin quaru tih.:r.. c:nbc:ddL-J m a L°\lppcr matri.l. Th.: tih.:rs n.:n: onc:nrc:d alo111: th.: dir.xllun tr.ivd,:d b\· the: in.:omn:11 pamdc:s. The ,h,,w.-nr.g particlL~ gc:n,:rat.:d Cc:r~ •'llkoJv light in the lib,:r;_ Pholuns •'TlllttL"ll wnhin the: numcm.::.tl aperture of th,: tibers \\,:r.: captur.:tl JnJ transp<>rt.:d through intcrnal n:fkctiL•ll to th,: tib,:r i:nds. \\ h,:n: thcy \\,:n: cum·crt.:J into phot,,dL,"trorts 111 ihc pl:,11i-cnhudc ,,f .1 phu1,1mult1pli..:r tuh.: 11''.\IT). The: J1glllLL-J ou1pu1 oJI ti:.~ P'.\ITs c,,mpri.scl th.: .-a!,mmct.:r ~•gnab.

The quartz tibc:rs i:onsL,t.:d of a 0 .. 10 mm diamo:1~-r .:on: surround.-d by U.015 mm 1h1d,: claJtlin;;. T11c tibcr.1 wcrc arr.ingcll in a h..::tagonal structun: . .:acl: tib,:r .-quidiswm r.2.J mml from its

2.J"""

2 .,,,n

c .. obsOtt>er~pl~e ; ;

;o-211.6mrn--o: ·r . . ,.___,=,___ _ __,i____ .. -. I

, ' ~1if=.rs ,

12 9 e 1 ... , .... ,

, , , f , 0 .. -........•

Reod-0-..,1 towers

Fi~ I. 11k: hJ•'C'f suua::turc: '"'' lhc .. .U.xuncra. The 111.\11.."t 1hows the, pu.tliolW\; ..,( tl..: 'lu.>rtL tib.:n.

■1h h8 / x ^ ± — —] qp U M R — ] [SN0B L e L !ZZu S k>0'B I—1* o .tr B 22*rt

=X] ? j _ ±j = / ? j XJ ' > ~ ±= h 4 ' j !X>j±= [ j±j j — > j W W j W X? ahs — — /' XK 9 J ±~ ~ ; j W K ~ % % j ± % _ /j =h 4 'j° ~ K K ^ E% XjW mhtR ~ ! /' j W j /j K /~ ± ; ~ ^ — j Tm hcR [ ' j? j ] EK ^ W X? J /' j K _ W W X? J 'h 4 ' j K _ ~ ± X— j /j ± K ~ ? /_ X? j W X? / ~ /_ #r sss * ^ _ ± /\ !X>j±=* [ 'XK' [ j±j J ±~ ^ % j W /~ !~ ± — /~ [ j±= h w _K ' /~ [ j ± — j _ =^ ±j W ca hb M cu — — A _ ? W K ^ ? /_ X? K W cbt !X>j±=h 4 ' j !X>j±= j] E/j ? W X? J ~ ^ / /' j > _ K9 ~ ! j _K' /~ [ j ± [ j ±j > ^ ? K ' jW /~ J j /' j ± * — _ K ' X? jW * % ~ X=' j W _ ? W K ~ ^ % j W /' ±~ ^ J ' _ ' j ] _ J ~ ? _ _ X± XJ ' / j^ XW j /~ _ L ' XX% = 5 L a s a s L - 4 h <

4 ' j j!!jK/X;j ±_ W X_ /X~ ? j ? J /' T h /~ ' ~ ! W XX= W j E/j K /~ ± [ _= mhub K— h X/= ? ^ K j _ ± X? /j ±_ K /X~ ? j?J /' v a mchc K— _ ? W X/= - ~ Xj ±j ±_ W X^ = ' mhcc K— h 4 ' j K _ ~ ± X— j /j ± — j_=^ ±jW nnhpc K— X? W j % /' Ta hmp UWwW ~ ± a a hr 5 m _ ? W [ _= K~ — % ±X=j W ~ ! m a /~ [ j±= TB XJ h m mh 4 ' j !X>j±= [ j±j ±j _W ~ ^ / _ / ~ ? j j ? W h _ ? W [ j±j — _ W j ±j W j j — j >° _ ^ — X? ^ — W j % ~ = X/ X~ ? _ / /' j ~ /' j ± j?W h

4 ' j K _ ~ ±X— j /j ± [ _= j* ^ X% % j W [ X/' /[ ~ W X!!j±Ej? / /° % j = ~ ! !X>j±h 4 ' j ~ ? ° W X!!j±j?Kj > j /[ jj? /' j=j !X>j±= K ~ ? Kj ±? jW /' j K _ W W X? J h 4 ' j K j ? /±_ /~ [ j ± T ! /c m K ~ ? /_ X? jW !X>j±= ~ ! [ ' XK' /' j W _ W W — J K ~ ? = X= /j W ~ ! ^ ~ ? ? ^ /K W =XXK_h 4 ' j ~ /' j ± /~ [ j±= K ~ ? /_ X? j W X> j ±= ~ ! [ ' XK' /' j * ^ _ ± /\ K ~ ±j [ _= = ^ ± ±~ ^ ? W j W >° ' ^ ±W E% ~ ° — j ± K _ W W X? J v? /' X= % _ % j ± * [ j X— X/ ~ ^ ±=j ; j= /~ /' j = /^ W ° ~ ! ±_ W X_ /X~ ? j!!jK/= ~ ? /' j !X>j±= [ X/' /' j ! ^ ~ ± X? _ /j W * ^ _ ± /\ K _ W W X? J h

- ~ ±j Wj /_ X= _ > ~ ^ / /' X= K _ ~ ±X— j /j ± * _ ? W /' j ±j _ =~ ? = !~ ± /' j Wj=XJ? K'~ XKj=* _ ± j J X;j? X? Dn’h

ahah E2(^ )2*6 (2^’!

4 ' j — j _ =^ ±j — j ? /= [ j ±j %j±!~ ±— jW X? /' j qu > j _— X?j ~ ! /' j Z ^ % j ± L ±~ /~ ? Z ° ? K ' ±~ /±~ ? _/ g w 0 P h 4 ' j W j /j K /~ ± [ _= — ~^? /jW ~ ? _ % _ /!~ ±— /' _ / K ~ ^ W >j — ~ ; jW ;j±/XK_ ° _?W _ /j ±_ ° [ X/' ±j =% jK / /~ /' j >j_— * =~ /' _ / /'j > j_— K ~ ^ W >j = /jj ±jW X? /~ _ ? ° W j =X±jW X— % _K / %~ X? / ~ ? /' j K_E~ ±X— j /j ±h

8 % = /±j _ — ~ ! /' j K_ ~ ±X— j /j ±* _ /± XJ J j ± K ~ ^ ? /j ± /j j =K~ % j [ _= X? = /_ jW h v / K~?=X=/jW ~ ! c =K X? /X_ E/X~? K ~ ^ ? /j ±= ~ ! W X!!j±j? / =X\j= T!±~— a U a — — E /~ c d c K— E' * [ 'XK' _ ~ [ j W _ K'~XKj ~ ! /' j >j_— = % ~ / =X\j !~ ± /'j ±j K ~ ±W j W j;j?/=h 4 [ ~ W ±X K ' _ — > j ±= [ X/' h±h ± ±j _ W ~ ^ / — _Wj X/ % ~ == X> j /~ W j /j ±— X? j /' j X— % _ K / % ~ X? / ~ ! X?W X; XW^_ % _ ? XK j = [ X/' _ % ±jK X= X~ ? ~ ! jhs ha — — h , ~ [ ? =/±j_ — ~ ! /'j K _ ~ ±X— j /j ± * /[ ~ _ ±Jj =KX? /X_ /X~? K ~ ^ ? /j ±= [j±j X? = /_ jW !~ ± — ^ ~ ? XW j? /X!XK_ /X~ ? h

4'j > j_— ^=jW !~ ± /' j /j=/= W j=K ±X> jW X? /'X= % _ % j ± [ _= _ % ~ _ ± X/° _ ? W — ~— j? /^— =jjK/jW =jK ~ ? W _ ±° > j _— % ±~ W ^ K j W >° ucs k j1 % ±~ /~ ? = X? K XW j? / ~ ? _ /_ ±J j / ~ K _ /jW _> ~ ^ / ccs — ^ % = /±j _ — ~ ! /' j K _ ~ ±X— j /j ± h B ~ ± /' j /j=/= W j=K±X>jW — /'X= % _ % j ± * [ j ^=jW /' j=j % ±~ /~ ? = %±X— _±X° /~ % ±~ W ^ K j > j _— = ~ ! j j K /±~ ? = [ X/' j?j±J Xj= ~ ! -? ~ ± mcs k j1 h

4 ' j K ±^ K X_ — j_ =^ ±j — j ? /= !~ ± T'X= % _ ± / XK ^ _ ± = /^W° [ j±j % j ±!~ ±— jW [ X/' /'j W j /jK /~ ± ± ~ /_ /j W >° bs® [ X/' ±j =%jK / /~ /' j ? ~ ±— _ ~ % j ±_ /X? J % ~ = X/X~ ? X? g - Z h v? /' X= = j /^ % * /' j W j /j K /~ ± =XJ?_= K ~ ^ W >j — j _ =^ ±j W _ = _ !^ ? K /X~ ? ~ ! /'j Wj% /' T ± ' _ / [ 'XK'

/ %;±±C

m)v) yj_—

/QhX kj1 j X

qu yj_— Tmcs kj1 — Z .

BXJ h cE Q ± Xj ? /_ / X~ ? UEAI /' j * ^ _ ± /\ / X / j ± K _ ~ ± X— j /j ± W ^ ± X? J /' j vK = /> K ^ — = /^ W Xj = ~ ! /' j j ! K K ^ ~ ! ± _ W X_ / X~ ? W _ — _ J j h 4 ' j ^=/ j ± ? ^ — > j ± X? J X= /' j = _ — j _ = X? B XJ h m

mmc


.'I . . lkdtur111 ,r .J. I .v,..L /,wr_ .-J .\l<11L ., Phr>- Ra B 1:17 r ::v11:. 66--7l

si.~ n.:an:st neighbors. Thc fibc:rs wcn: c:mbcddcd in 2.0 mm thick grooved copper platcs. They OCCU·

pi.:d 1.8''., of thc dctc:t."tor volume (I.~" when cxduding th.: cladding). The calorim.:tcr containcd in total .-...&JOO quanz fibc:rs. which were group..-d lo fonn towcrs. Each tower measun:d 52.9 • 54 nun! ,md contained 5•JS tib.:rs. The tibc:rs cxlending out the back of each luwcr wcrc bun..:hc:d to~oethcr. machined. polished and coupled through a hc.ugonal air light guide to a Philips XP:?O:o P:\IT.

The c:ITccti,e radiation kngth (.\'., I of thi:. Jet.xtor was 1.-'9 .. m. its nudc-.ir in1cr.1ct1on length ,;,.~, 15.5 1.m .ind ll~ \(L,[icrc: radius,,,.,., 1.55 crn. The 1.":lfonmetcr me-.isun:d 33.75 .. -:n in depth (2.17 i.,,. or ~.6.r., 1 anJ \\:L~ ..:ompris,-d ,,f 12 towers I Fig. I 1. The tihcrs ,.,,ere read out ;it ,.me .:nJ. and \\ere mad.: rclk-.;U\e by aluminum deposition at the: '-'thcr end.

Thc ,-.ilonmctcr w,.11 "°'iu1p~-d with twu ditfc:rent t:,. l'\-'"I of tibc:r. Thc ,mly d11Tcrcn,-.: b.:t,Hi:n th .. -sc tibcrs concerned thi: cladding. Thc central tower ( #51 cunum .. -d tibcrs of which the: cladding .. -unSL,tc:d .,f tlu<lnnat ... -..1 ,ili<.."a. The other towers contained tibcn of which the: quartz cure: was surround.:<l by hard-polymer .:ladding. In thts paper. \\C 1111111 oursclh-s to the: study of radiation e!Tc.:t:. on th;: tibc:rs v. ilb lhc fluurin.1t.:d quaru daJdin~.

:\Ion: dctaib ;ihout this 1.-alorimetc:r . .ind the: re-.1SOn• for the design ,;hoio:s. arc 1,-i,c:n in (3(.

I ' 1, : . : ~, UL lk:im ,o . .sc..,v.·,

!.!. Te:st beam setup

The mc:a.sun:mcnts wen: performed in the H-' beam line of the Super Proton Synchrotron at CERN. The detector was mountl!d on a platform that could be: mo\,:<l ,ertic.-ally and L1t .. -r.1ll~ with l'l:SP\:Ct to the bcam. so that the beam .. -uuld be st .. -.:r.:<l into .1ny Jc:sir.:<l impact point on the ... 111-orimctc:r.

lipstrc:-.im uf thc calorimc:tc:r. a triggc:r counter tclc:s.:opc was installed. It ,-uns1s1,-J of 5 s.:ir.ttl!Jtion ,-uuntc:rs oi dilfcrent siz,.'S (from 2 • ~ mm: lo 5 • 5 cm! 1. which .11l,1wed a ch,,i,,: of th.: bc:-.1111

,pot svc for the r .. -.:ord,-u C\C:lll>. Two Jnft chambc:rs with .f.l' rc:idout 111ade it possiblc to dctcrmine the impact pomt of mdi,1dual parttcks \\ith ,, pr..-...-i,.ion \lf .:.O.~ mm. Du,\n;tre-.un of lb ,Jlori:neter. two large: -.:iulill;iuun ..:uunt.:rs "'We install..-d for muon iJentttk.ttion.

rl:c: bc.1111 us..-d for thc tc:su Jc::,cnhcd in tht~ paper \\;13 a polmty and momentum s.:kct .. -J "''-·undary bc:-.1111 prndu,-.:d by -'50 GeV protur., incident on .1 target lo..:-.1.t .. -d about 550 111 up,trl:'.tnt of the .:alonmctc:r. f,Jr the tot.,; Jc:s.:rih<.-J 111 tf:l.'i papcr. we u:1c:d thc:se protons pnmanly to prnducc: bc:-Jm:. of c:k,.1n,ns with c:neri;i,-s of XII or I ;IJ GcV.

TI1c: cru,:1a.l me-asuremenu for this parttcul.1.r study '4'e~ performed wuh the dc:tc:.."tor rotated by 'JO" "'ith r .. -sp,:ct t,_, the: normal operating ix1sition in C\IS. In thb <,.;!Up. thc dct,-ctur ,ii;nab ;,;oulJ bc: mi:.isur.:<l a.- a function of the: Jc:pth 1=1 al "'h1ch

tu ~rr·,

Fig. !. Or1.:11lalK1D of the quart, tib:r ,-alunma:t.:r dunn, the t.:>tbcun ,tu.!Jo u( the .:tf,'Ct.1 of r....tuuon d;uuai;,,. Tb.: r.,,.,-r numb,:nng ii lb.: .am.: a.• 1n Fi~ I

115

h1 h <v%S ** —N 'd N WR5p [*1<0 R * $ ,0<> N* k>_6 I11B o [WJ »B JbVJ■ 22* JW rb

/' j g j ±j? 9 ~ ; XJ' / [ _ = J j? j±_ /jW h 4 ' j > j _ — % _ ± E/XK j= /±_;j jW X? /' j E X W X±j K /X~ ? T=jj B XJ h a'h

, ^ ± X? J /' j — j _ =^ ±j — j ? /= * /'j > j _ — % _ ±/XK j ±_ /j = [ j±j =^K' /' _ / /° % XK_ ° _ !j[ /' ~ ^ = _ ? W j; j? /= % j ± =%X [ j±j ±j K ~ ±W j W h 4 ' j =% X= _ = /j W ahr = _ ? W [ j±j ±j% j_ /jW j ; j ±° mu =h 4 ' j [ XW /' = ~ ! /'j K ~ X— _ /~ ±= X? /'j > j _ — X? j [ j±j K ' ~ =j ? = ^ K ' /' _ / /' j K ~ ? /± X> ^ /X~ ? ~ ! /' j — ~ — j? /^ — ^ ? K j ± /_ X? /° ~ ! /' j > j_— % _ ±/XK j = [ _= ? j W XW > j h © Ahs hc R i ; B v k j 1 hh

hWRW £2*m„’^ *Ym b*VU);*Û„Y „3 x2 m2^2b^„;

4 ' j K _ ~ ±X— j /j ± = XJ ? _ = [j±j / ± _ ? = % ~ ± /j W /' ±~ ^ J ' ZQ — ~?J 0 k Ec Z K_> j= ~ /' j K ~ ^ ? /X? J ±~ ~ — h 4 ' j =XJ?_= [ j ±j !jW X? /~ _ ? _ ~ J E /~ EW XJ X/_ K ~ ? ; j ? j ±= Tx , g =' [ X/' _ W ° ? _ — XK ±_ ? J j ~ ! mc > X/= _ ? W _ j_=/ K ~ ^ ? / K ~ ±±j = % ~ ? W X? J /~ cs !g h [ ' XK' [ j±j ~ % j ±_ /j W _ / _ J _ /j [ XW /' ~ ! rs ?=h

x X? W X; XW ^ _ Kj= ~ ! /' j K _ ~ ±X— j /j ± [ j ±j K _ EX> ±_ /j W [ X/' ZQ k j1 j j K /±~ ? = X?KXWj?/ ~ ? /' j Kj K j ? /j ± * Xhjh /±_;j X?J X? /' j W X±jK /X~ ? T=j j B XJ h a'h 4 ' j L - 4 J_X?= [ j±j K ' ~ =j ? — =^K' _ [ _° /' _ / /'j _ ; j ±_J j =XJ?_ !~ ± ZQ k j1 A j jK /±~ ? = j ? /j ± X? J /'j K j ? /j ± ~ ! _ K _ ~ ±X— j /j ± Kj K ~ ±±j =% ~ ? W jW /~ _ > ~ ^ / css x , g K~ ^ ? /= _ > ~ ; j /' j %jWj=/_ ; _ ^ j X? /' X= Kjh Z X? Kj % ±_K /XK _ ° _ /' j ='~[ j± j ? j ±J ° [ _= W j % ~ = X/j W X? ~ ? j K _ ~ ± X— j /j ± Kj* /' j L - 4 J _— K ~ ± ±j = % ~ ? W j W /' ^ = /~ EEs hn %g ik j1 T ~ ± r x , g K ~ ^ ? /= % j ± k j1 Xh

4 ' j =/_> XX/° ~ ! /' j K _ X> ±_ /X~ ? [ _= K ' j K 9 j W =j; j ±_ /X— j= W ^ ±X? J /' j /j = / %j±X~W= T /° % XK_ ° j; j±° a W _° =' >° =j? W X? J _ ? ZQ k j1 j j K /±~ ? > j _ — X? /~ /' j K j? /j ± ~ ! j _ K ' _ ? W j; j±° K _ ~ ± X— j /j ± Kj _ ? W — j _ =^ ±X? J /' j = XJ ? _ W X= /± X> ^ /X~ ? h 4 ' j — j_ ? ; _ ^ j = ~ ! /'j=j W X= /± X> ^ /X~ ? = [ j±j ±j % ±~ W ^ K j W ~ > j / /j ± /' _ ? a R X? /' j =j — j_=^ ±j — j? /= * !~ ± _X K ' _? ? j = h

hWgW Ex2 2q!„(’;2 ^„ ;*mU*Û„Y *V :d

4 ' j ±_ W X_ /X~ ? j] % j ± Xj ? Kj W >° K _ ~ ±X— j /j ±= ~ % Ej ±_ / X? J _ / n e V+'’ d c _ / /' j ) q g ~ ± XJ X? _ /j = % ± X E— _ ±X° !±~ — /' j !! K ~ X= X~ ? = /' j— =j; j= T_ = ~ % % ~ = j W /~ >j_— EJ_= X? /j ±_ K /X~ ? = ~ ± ~ ==j = /' _ / ~ K K ^ ± [ ' Xj !XX?J /' j _ K K j j ±_ /~ ± ±X?J='h 4 ' j — ~ = / _ > ^ ? W _ ? / %_±/XK j= j — j ±J X? J !±~— /' j=j X? /j ± _ K E/ X~ ? = _ ± K =~ !/ T~ ±W j ± m k j 1 ' % X~?=h > ~ /' ? j ^ /±_

_?W K ' _ ±J j W ~ ? j = * % ±~ W ^ K j W X? / ' j ! ±_ J — j ? /_ /X~ ? ~ ! ? ^ — j ±~ ^ = * ^ _ ±9 = * W X* ^ _ ±9 = _ ? W J ^ ~ ? = /' _ / % _ ±/XK X% _ /j _ / /' j K ~ ? = /X /^ j ? / j ; j X? /' j K~ X= X~? % ±~Kj==j=h

Z X?Kj /' j j ? /X±j j?j±J° ~ ! j j K /±~ — _ J ? j /XK Tj— ' ='~[ j±= X= W j % ~ = X/j W — _ ±j J X~ ? ~ ! X— X/jW W j % /' * — ~=/ ~ ! /' j j!4jK/= ~ ! ± _ W X_ / X~ ? W _ — _ J j ~? /'j K _ ~ ±X— j /j ± % j ±!~ ±— _ ? K j _ ±j /' j ±j = ^ / ~ ! /'j % ± ~ EW ^ K /X~ ? ~ ! j — ='~[ j±= X? /' j K _ ~ ± X— j /j ± X/=j!* /' ±~ ^ J ' /' j p p WjK_° ~ ! h/^=h 4 ' X = % ±~ Kj== X= ±j E=%~?=X> j ! ~ ± W Xj ±_ W X_ /X~ ? W ~ = j = ±jKjX;jW X? /' j ® ' ~ //j = /£ ±j J X~ ? = ~ ! /'j j ] % j ± X— j ? / * ~ K_ /jW =~ — j n c ± _ W X_ / X~ ? j?J /' = X?=XWj /' j K _ ~ ±X— j /j ±= /' _ / _ ±j X? = /_ jW ? j _ ± /' j > j_— % X% j T mmh

4 ~ — X— XK /' X= = X/^ _ /X~ ? X? ~ ^ ± ±_ W X_ /X~ ? ' _ ± W E?j== = /^ W Xj = * /' j K _ ~ ±X— j /j ± W j = K ± X> j W _>~;j [ _= j]%~=jW /~ _ ? X? /j?=j > j_— ~ ! s hc k j1 j jK/±~?=* % ±~ W ^ KjW >° /' j X? j_ ± X? 7j K /~ ± ! ~ ± ) q L m ) v) mh ! XK >j_— X? /j ? = X/° W ^ ± X? J /' X= j ] % ~ = ^ ± j [ _= /°% XK_° _ !j[ /X— j= m s mm j jK /±~ ? = % j ± = j K ~ ? W h

4 ' X= > j _ — [ _= =/jj±jW % j ±% j ? W XK ^ _ ± /~ /' j — X±±~ ±jW !X> j ± =^ ±!_Kj T Xhjhh X? / ' j E X W X±j K /X~ ? ' X? /~ /' j K j ? / ± _ ±jJ X~? ~ ! 4 ~ [ j ± c T=jj BXJh a'h v? _? j ] % ~ =^ ±j /' _ / _=/jW _ > ~ ^ / n W _ ° = * _ /~ /_ ~ ! mhuc © v TvmN j j K /±~ ? = [ X/' _ ? j ? j ±J ° ~ ! v' c k j1 j_K' [ j±j = j ? / X? /~ _? _ ±j _ ~ ! _ !j[ j ? ± 4 ' j

/~[ X = +

±~[ X ? c■ Q/-/V

h9

+hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh# /X/±[?XEX? d ±+ $ —X

B XJ h zh , /+ ? > ^ /^ l ? ~ ! > K^ — % _ ± ^ K 9 = _ K K ^ — ^ _ / j W X? 4 ~ [ j ± c W ^ ± X? J /' j j ] % ~ = ^ ± j ~ ! T'j K X ^ ? — K / K ± _ / 8 ) h v? / ~ / _ mhYc U ms® j j K / ± ~ ? = ~ ! 8 c k j1 [ j ±j ^ = j W ! ~ ± /' X= % ^ ± % ~ ± / h 4 ' j

, ^— >j±' _ ± K _ — K _ _ ^ ±; !~ ± /' j % _ ± / X K j / ^ ] j = X? / _ ^ Taz U ac ? ^ ? ♦ X W ~ = X— j /j ± = — ~ ^ ? /j W ~ ? / ' j K _ ~ ± X— j /j ± = ^ ± E!_ Kj h 4 ' j ° _ ± K j /% ± j - K W X? ^ ± ? ^ ~ ! /? j J ~ ±_ / = h

FFV


.,· .U.c/a,nn ,r ,,/ / .\"ucl /11..u IINi .\frth ., /'In>. R,,s. 8 tr: :uo:, 66-7~

th.: Ccrl-nkov light was g.:ru:rJtal. The: beam partick·s tm,dcd in the -i dir((."tion (sec Fig. :!J.

During lhc ms:a.sun:m,:nt.:;, the be-.un particle ratc:s wc:n: such that typic-JDy a fi:w thousand .. ~-mts pc:r spill wcn: ra:unlc:J. Th,: spills last.:d :!.6 sand wc:n: rt:pc'Jtt.-d every lJ s. The widths of th.: colliruatur.1 in th.: bc:am line \~c:rc chUl!Cn ,uch that th.: cuntnbutiun ,,f th,: ml>mc:atum ur.c.:rtainty of _t_hc __ bc::Jm partic!c:s w.is ncghgibl.:. -... 0.5'''•/ ,_'£ 1GcV,.

:.J. R~uJ,iu/ u11J culd>rullun of rh~ Jcuaor

The ctlorimc:t.:r sign.tis were transported through :SO m I.mg RG-58 i.:-.1bb to th.: counting n,um. Th,: signals wc:rs: fod mtu analog·tl,)-<ligital .:on,crtc:rs cADCsl with a dyn,1m1<: range of 15 bits and a lc:ast count cllm:sponding to 50 fC. which were: op,:r;it,'\l .11 a g-.1te width of 60 ns.

All mdi,·1dual .:dl, of th.: <.-alurim.:t.:r w._-r,: .:-.1l-1t>r.111:-d \\llh SO Ge\' ckctrnns in.:1Jc:nt on the ,-ell ._,:nt.:r, 1.1:. tr,l\ding in the: -= din.-.:tiun (,-« Fig. :!l. Th.: P:\IT ~1i11; wcr.: ..:h,,s.:n m ,u,;h .1 wa~ that rl:c a,·.:r.ige ,ignal for SO G.:V .:k.-ctron, ait.:nng th.: ._-enter of a 1.-alurmn:tcr 1.·dl corr~ponJed tu .ib.1111

500 ADC .:uunts atx,,..- the pc.,kswl ,alu..- in this 1,.-cll. Sim:.: pra..:tH:ally all th.: shllwcr cnc:rgy W.1$

deposited in one c-alorim.:tcr cc:11. the P:\ IT g-.un com:spondc:J thus to --0.3 pC/G,:V (or 6 ADC ..:ounts p,:r Gc:\'1.

The: stability of th.: c-alibratiun ~as ch ... -ck..'\l s.:-.-cr-.Ll timc:s Junng the: tl:St p,:riud:, uypically C'oCry ~ daysl by sending an 80 Gc:V electron bc:-Jm inti,) the: 1.-i:nter of c:-Jch and e,·c:ry ~-.ilorim.:tc:r 1.-ell and measuring th.: sign.ii distnbuuon. Th,. m.:an values of thc:5e distributions were reproduced to bc:th:r than .?'~'., in th= mc:asun:m .. -ots. for all channels.

!. -I. n,e exposure 10 ruJiatu.111 ul UL

The mdiatiun ,:xpcri.:m .. -i:d by c:ilurimc:t.:rs op.:r.11mg at 3 < l'II < 5 al the LHC unginatc:s primarily from the: pp collisions thcmscli.cs (as opposed to bcaai-g:is interactions or loss.:s that u...-cur while: filling the: ~ .. -i:lerator rings). The: most abundant p.iniclcs emerging from these int.:rJctions are soft I order I Ge V) pions. both nc:utral

116

and charged onc:s. pruducc:J in the frJ!,'111c:atation of numc:rous quarks. diquarks and gluons that p-.inicipatc at the cunstituenl le:,;,:! in the: collision pnx:cs:s.:s .

Since: the: c:ntirc ,:ncrgy of dc:ctrumagnc:tic (c:m) showc:rs is dep~ltt.-d in a n:g:ion of limit.,'\! d.:pth. most of th.: effects of ro1diatiun damage on the: calorimet.:r pcrfum1an .. -c are the: n.-sult of the pr,1-duction of ,:ru showc:rs in the: calorim.:t.:r itsdf. through the: :! d,-c-Jy 0f :t"s. Thu proc .. -ss IS re;ponsible for th.: r.1J1.1tion do..:s rc:cci\1,.-J m th.: "hottest"" n:gions ,,f th.: expcrim.:nt. 10<:atcd sdme 3 5 raJiation k.-ngths ins1dc: the c-Jlonmc:tcn that .trc: installc:J nc:ar the bc:-.un pipe ( l j.

Tu mimic this situallon in our rJJtation hJrdncss studies. thc: t.-alunm.:t.:r Jcs.:rih...-J .ibo,c was c:.ipusc:d tll an intense: b.:am of U.5 Ge\' .:lc:ctnms . proJu .. ~-J by the: lmc:-.ir inJcctur for Ll:P 1LIL1. f"he beam im.:n.sity dunng this c:xposun: ,,a.s typt..:ally ;i

tc:w timc:s to" .:1..-ctrons p,:r S<:\:Olld. Thi, b..-am wa.., stc..:n:d pcrp,:mlit.-itl.1r 1,, the:

mirrored libcr surtat.-.: 1i . .: .. in th,: ·= Jir,i:tlun) inlu the .. -.:nlral rcgtlln ,,f T ,rn..:r 5 /-,.: fig. :1. In an .::tposun: that lastcJ ab..mt 3 JJ~'- a lot.ii uf 1..:; , 101

• ekctrons \\llh an cn.:rl!'w of ll 5 (i.:\" .:adi w.:n: ..:nt mtu ,Ill ar::-J of a ·i·.:w ..:m:. The

I •

0.

I •

-10 •

1011,f_Jt~

r. .•. ----~-·-· - ... • ... , .. , ....... '! ... ·.-? ::. , .... "! ... ·: , --·---- -----\~ ., .,,. JoU ...... •1 ..

. ·------~ ...... -- . . - .. ,::,., ...... ! ... ,.

. .. .:- . ..: .. -... : ' .... 'C J.OII ~ ... .

-• - \ltfWIII

-IO 0 Ill

C

"' ~

F1;;. l. Dblnbull4•n uf bGun rarudo ..:.;wnulJt..-.J 111 T "'""' ~ .iunn, lhi: ,-..posurc ..,( 111.: .:alu~~ :u UL In iuWl. l.~S • hl" CL"l."tR>IIS ofllj c;,,v W,TC u...-d for !ht< pu .... ~. nic aumh:n :in: .1 mi:-.a.urc for th&: part,..ic 1huo m IOWII (~ , 1.5 mm:• dus.zmct..-rs awunla.l "" rb.: "'-;i.Junm.:rL~ sur~ f.,..-., Tl,cy ;ire etpre.,.d lA urui.. ..,, m.,~.h.

4Q h1 } vN>_0N* 0 N N%B ( WRNp \0R N0 q*% ,—<vB S k>_1B I—1 V ](NH N'cy'\ 2} *rBQ

W X= /± X> ^ / X~ ? ~ ! /' j X— % _ K / % ~ X? /= ~ ! /' j > j _ — j j K /±~ ? = X? 4 ~[ j± c X= X? W XK _ /j W X? BXJ h nh [ ' XK' = ' ~ [ = /' j ±j_W X?J= ~ ! _ ? _ ± ± _ ° ~ ! =— _ Ta hc e a hc — — e ' W~=X— j/j±= — ~ ^ ? /j W ~ ? /'j K _ ~ ± X— j /j ± A= ! ± ~ ? / !_Kjh

4 ' j K _ ~ ±X— j /j ± > j K_— j * ^ X /j ±_ W X~ _ K /X; j X? /' X= % ±~ K j == h 4 ' j W ~ — X? _ ? / ±_ W X~ _ K /X; j ? ^ K XW j [ _= [ g ^ h ±j =^ /X? J !±~? / /' j ±j _ K / X~ ? ®♦g ^ X ° h ? X[ g ^ h X? X/ X_ /j W >° °= [ X/' j ? j ±J Xj = ~ ! _ ±~ ^ ? W ms - j1 14U*Y^L;2(„Y*Yb2!;„m’bÛ„Ya' [ ' XK' _ ±j _ > ^ ? W _ ? / ° J j ? j ±_ /j W X? K— =' ~ [ j± W j ; j ~ % — j? /h 4 'j ' _ !E X!j ~ ! /' X= ? ^K XWj X= mahp ' _ ? W /' j ±j !~ ±j /' j — ~ W ^ j ' _ W /~ K ~ ~ W~[ ? !~ ± _ > ~ ^ / /' ±jj W _ ° = > j !~ ±j X/ K ~ ^ W > j /±_ ? =% ~ ±/j W > _ K9 /~ /' j q u > j_— * [ ' j ±j /' j /j = /= /~ _==j== /' j j!!jK/= ~ ! /'j ±_ W X_ /X~ ? [ j ±j % j ±!~ ±— j W h

nh , _ /_ _?_°=X=

D \W C„(2 !;„3UV2(

4 ' j /' ±jj EW X— j? = X~ ? _ W ~ = j % ±~ /Xj= X? W ^ K j W X? /' j K _ ~ ± X— j /j ± — ~ W ^ j [ j ±j W j /j ±— X? j W [ X/' /' j ' j % ~ ! w k Z u - ~ ? /j g _ ± ~ = X— ^ _ /X~ ? = ~ ! /' j W j ; j ~ % — j ? / ~ ! shc kj1E j j K /±~ ? ='~[ j±= X? K ~ % E% j ± DcV v/ [ _= ±jKj?/° =' ~ [ ? /' _ / =^K' = X— ^ _ /X~ ? =

JX;j _ J ~ ~ W W j =K ±X% /X~ ? ~ ! /' j ±j j ; _ ? / W ~ = j % ±~ E!Xj= Dr zh 4 ' j K _ ~ ±X— j /j ± — ~ W ^ j [ _ = W j =K ±X> j W _= _ —_==X; j > ~ K 9 ~ ! K ~ % % j ± * =^ > W X; XW j W X? /~ Kj= [ X/' W X— j? = X~ ? = ~ ! c d c +■ c — — Ah 4 ' j w k Z u % ±~ J ±_— = X— ^ _ /jW j — =' ~ [ j ± W j; j ~ % — j? / X? /' X= = /±^ K /^ ±j _? W ° Xj W jW /' j j?j±J° W j% ~ =X/jW X? j _ K ' _ ? W j;j±° ~?j ~ ! /' j = j Kj=h B ±~— /' X= * /' j W ~ = j TX? z i9 J ’ K~ ^ W > j W j /j ±— X? j W X? _ = / ±_ XJ ' /!~ ±[ _ ±W [_°h

Z ~— j ±j = ^ /= ~ ! /'j=j = X— ^ _ /X~ ? = _ ± j =' ~ [ ? X? BXJ=h u _ ? W ch 4 ' j=j ±j=^ /= K ~ ? K j ±? ~ ? J X/^ W X? _ _?W _ /j ±_ W ~ = j %±~!Xj= X? W ^ KjW >° mhuc U msA® j jK /±~ ? = ~ ! s hc k j 1 =% ±j_W ~ ^ / ~ ; j ± /' j !±~ ? / !_Kj ~ ! 4 ~ [ j ± c _ = X? W XK _ /j W — BXJ h n

v? B XJ h u h /' j ±_ W X_ /X~ ? W~=j X? W ^ K j W >° /'j=j %_±/XK j= X= J X;j? _ = _ !^ ? K /X~ ? ~ ! /' j W j % /' hA X?=XWj /' j K _ ~ ±X— j /j ± * !~ ± /'j K j ? / ±_ _; X= TK E G # s ' _ ? W !~ ± _ X?j ~K_/jW a K— _ > ~ ; j /' X= _;X= /h; E s h ° E a K— h =jj BXJh ?aW 4 ' j — _ / X? X^ — W~=j X= ±j_K' jW _ / _ W j % /' ~ ! _ > ~ ^ / n K — ~ ? /' j Kj? /±_ _;X= _ ? W _ — ~ ^ ? /= /~ E E r 1 k ; Tr s s - ±_ W Xh 4 'j !XJ^±j _)=~ =' ~ [ = /' _ / /'j K_ K^ _ /j W z ~ = j _ / /'j K _ ~ ±X— j /j ± A= ! ±~ ? / !_Kj T ± E s ’ X= X? j]Kjj?/ _J ±jj— j? / [ X/' /' j — j_=^ ±jW W ~ = X— j /j ± ; _ ^ j m m&lc - ±_W h

4 ' j X? W ^ K j W W ~ =j= _ +■ E a K— _ ±j =— _ j ± /'_? T'~=j ~? /' j K j ? /±_ W j /j K /~ ± _;X=h x =~ * /' j — _; E

X = ♦

G msU l=Dzzv

msU

+~&~ X ms X = a s

,j%/' »X K _ !~ ±— j /j ± * C TK—'

B XX7h u h 4 ' j ± _ W X_ / X~ ? W ^ + j X? W ^ X K W — _ > ~ K 9 ~! K ~ % % j ± > ° v u c U Iq oU j j K /±~ ? U ~ ! s hc gzK1 W X= /± X> ^ /j W _U — /' j j ] % j ± X E— j ? / _ j ] % ~ = ^ ± j ~ ! /' j K _ ~ ± X— j /j ± — ~ W ^ j T=jj B Xj h n'h Z ' ~ [ ?

_ ± j / ' j z ~ = j = ]+ _ !^ ? K /X~ ? ~ ! W j % / ' ~ ? /' j K j ? /±_ ^ ^ ~ ! X' j j ] % ~ = j W _ ± j _ _ ? W ~ ? _ /X?j ' K — _ > ~ ; j /' X= _] /; 0 j = ^ /= ~ ! w k Z u = X— ^ _ /X~ ? = h

■n LU E+ s v a aqjXJ'/ X? K_~±X—j/j±* ° TK—'

BXJ h ch 44XK ± _ W X_ / X~ ? W ~ = j X? W ^ K j W X? _ > ~ K 9 ~ ! K ~ % % j ± >; v uc ™ ms U j j K / ± ~ ? = ~ ! s hc k j 1 W X= /± X> ^ /j W _ = X? /' j j ] % j ±XE— j ? /_ j ] % ~ = ^ ± j ~ ! /' j K _ ~ ± X— j /j ± — ~ W ^ j '1'€ B XJ h zlh Z ' ~ [ ?

_ ± K /' j _ /j ± _ W X = / ± X> ^ / X~ ? U X+! /' j ± ^ W ^ 8 ~ ? z ~ + j h _ / /' ±j j /XE !j ±K? / W j % /' = X? = XW j / ' j > ~ K9 e c hm s _ ? W mc K — h 0 j = ^ /= ~ ! " k Z u

/X— ^ _ 8 ~ ? = h

mmp


;,; ,IJ..,·in,nn ,r ,d_ I .\u.·! /n.,rr .,,,.J !J~liL ., Plrr.r. Ra. 8 tr , _YJ11:, OIi -~.,

distribution of the impa..--t points of the bc-.im c:let.·1rons in T,1wc:r 5 is imlic:lled in Fig. 3. which mows the n:aJings of an array of small (1.5.,, 1.5 mm~) Josimc:ters mounted on the c-.ilorun,:tcr·s front face.

The c-.ilorimctc:r b.:c.ime quite r.wioa..·the in this prO\."\:S:i. The Jominanl rJJioacti"c nuclide w;13

... Cu. resulting from the r::-Jction .,Cu(·r.n1"'Cu. initiateJ by ·ts with ener1:,-ics of arounJ 10 ~kV (!(icurr-r.:sunanu pruJi,.·rim, I. which are abundantly ~'l:nc:ra!ed in c:m shower Je\c:lopment. The: half-Iii.: of this nudide is 11. 7 h and 1herc:iorc: the module had to cool Jown for about thri:,: Jay!> before 1t .:ould b.: lr.import~-d ba.:k 10 1h.: H-1 beam. when: thr: t.:sts to .issess the eff~-.:ts of the r.iJiauon were pcrfonu,:J.

3. Data :malysi,

The thr~'\!-Jimensional ,fos.: prnn!.:s indu~ .. --d in thr: calorimeter modul.: were J.:1.:rmin.:J 1, ah the help Jf EGS4 '.\lonte Carlo simul.iuons of the J~..,elopmenl of U.5 GeV d.xtwn sho\\,:rs in copper (5) It WJ!i n.'l.l!ntly sh,mn that such s1111ulations

~

,.•,-----------------~

, .. ,o•

t 1:

...... •.

• I • t • • t o e •

, .... ..

I• , --~ . .;llllt:a .,..s,I ' I '• l "' '

·.

·.

,o·o._ ____ ,----,o----,,---'~,a Ceplb 11 calanmetar, z (ant

ri;. "· Tho: r.i.ballun JO><: inJ1L.-.J m a bl,,d, "' ,opp,:r by I .is • IH" do:ctrun:, uf 0.5 (kV JDtnbutal •• m lb.: cxpcnrn<:,1t.u .:x~ of 1he calonn..,1.:r moJuJ.: (5<1: Fit<- JI. Sh.,...n = lb.: Ju:,o :i.. a fun,'!Jon uf J,:plh un th.: ,i,nlr.u :w.,, u( th.: ,espo>CJ ;uc:s :u,d oo J h11< ! .:m ab.,,e 1ru. '"''- R.:sults uf EGS-1 ;,m,ubu,,ns.

117

give a good dc:54.Tiption of the rcl,:vant Jose: profik:1 (6J. The 1.-alorimelc:r module Wil.\ Jescribc:d a.1 a mas:ii\c: block of coppc:r. subdi\id .. -d mto cells with dimc:nsions of5 "5" 5 mm'. The EGS-' progr.im simulated .. -m shower J._-vdopmcnt in this st11.k.'1un: anJ yidJ.:u the c:nc:rg} deposited in .:a.:h .mJ e\·c:I)

on,: of tl:o:sc: L'Clls. From thi.~. thc Jo,;,,: (in J/kgl could b.: J.:termir.eJ in a ~tr.ughtlon\:ml way.

S.,111,: result,; of these: .imul.itions .ire shown in Fig:; . .i ;J.11d 5. Thc:s.: n:sulu cunc~-rn 1,mgituJinal anJ Lu,:r.il Jose: prntilc:s inJu1. .. -d by 1.-15 , Io•• :lectron..,; 1.'f 0.5 GeV spn:;1d out ll\ er the frlint face: of T o\A.;:f 5 a:. ind1L";1.t,:d in Fig. 3

In Fig. 4. thc r.idiauon Jo,.: inJu1.-.:tl by 1h~-,.: particl.:s is giwn a5 a funcuun of the Jc:pth 1:1 inside the: .. -alurimeti:r. for 1h.: ~-cntral a.,i, ( c 0

_1· ~ II) anJ for a lin.: lucarcJ 2 cm .ib..1'e 1t:i., a,h l.f ~ U. r -- 1 cm. s..-e Fig. :1. Thc ma,mrnm lim.: is reached at a Jeplh llf about 3 ~-rn on the centr.il ;uis .inJ ;imounl\ lo -6 '.\-!Gy <WI '.\lr.iJr. Tl:e ligure .iL-.o ,ho\\ s th:11 lhe 1.~rkula1~-d Ju-.: at ll:..: calorimeter·~ front faLl! <= - OJ L~ m .:."ts-cllc:nl ;igr,-::mcnt "'ith tl:e mca:.ur~J Jo~imc:ter \alue I 1'15 .\lraJJ.

The indm:c:J Jos.:s at 1· ~ 2 ,m are >nt.illc:r th.in tl:ose ,>n th:: c1.-ntr.1l J.:1,-cll>r Hi.,. ,\I.so. the mat-

:,>· • .----------------~ ! ...................

. · .. -~· .... ' .. ·•. l _. .. ,· I .· .•' ... · .. ... . ............... .

B ,~·· r :•·'.. -~. I C J ••••• •••••• •,i.

l-·;;=' . .... . ..... :·· .:J , .. ~: .... ·-· .---,-~·"·1

f z•Jc,n f 1·,

I 1•10~ ~ :•l~cm'.

••''~ ------------------' •l -: • t O I

Halgt,1 In calonmerer. y (em)

fig. 5. fh.: r•.tr..cwn J....: llllllL'I.U 111 • bl.>d. u( ,.,~ h> 1.-l~ , IO'" d..-..'trun.1 .,( 0.5 (;...V JL<l/lbul,-d a.< Ill Ibo c.t('Ctl•

m..-ntal .:xpo,.un: o( 1hc .:alonmcl4T modulr, u.-., Fi~. h !\ho .. -n ••~ lhe L:itcnl .!utnbuUutb ,,( 1hc ruJwlhm J0><. al tbr.-,, Jrf. ftttnt J.:p1lu ,n.iJ.: th., bluck.: S, JO .u,J IS .:m. R.:sull• of [C,S.i ,,mulacwns.

1 Nv <*R** N N qNB < 2/UX :*<N0 'SE ,—]>B S k>€N I—€ o [WJ jN,{j » r r E AX! 4

< as M8 p’cKQPg ms :~ c

4~[j± u

4~[j± c

4 ~[ j± r

4~[j± /~

yj_— T vZQ kj1 —e 7

!Y Uas ±

n Xd7~ T©~ vv >^ ,

6.QgX»1j X>~»K?

Mp

.c o

U u

6k•■, p* y^••k] SvO j

BXJh rh , j=] /~ ± JK;?X;±l X? X]E hAEEhÊ♦X [X/' mcmA g9E1 7 / 7 ± h 7 X_ hX? 7 //[ hX;K±EXEK /BgX 1v X Y/_/K ~! /'j hE?K/J° X[!Aj7=XjX X? ] Xj /K K /^ ± _ ? W /? =~—j ~ ! X/= /~[j±= >° /'j l ' ~ [ j±h± hj jjK/±~?= X> X h Z j j /j=/ !~± Wj/_X=

X— ^ — ~ K K ^ ±= _ / _ _ ±J j ± W j % /' T r K— ;j±=^= n K? Xh 4 ' X= X= _ K ~ ? =j * ^ j ? K j ~ ! /' j )_/j±_ > ±~ _ W j? X? J ~ ! /' j % ±~ !Xj _ = /' j =' ~ [ j±= W j ; j ~ % X? Wj% /' h 4 'j _ //j ± !j _ /^ ±j X= X^ = /±_ /j W X? BXJh z h [ 'XK' ='~[ = /' j _ /j ±_ W ~ = j % ±~ !Xj= _ / /' ±j j W X!!j±j? / Wj% /'=e ch m s _ ? W mc K— h

4 ' j ~ ? J X/^ W X? _ W ~ =j % ±~ !Xj= = ' ~ [ ? X? BXJ u _ ±j _ ±j _ =~ ? _ > j _ % % ±~ ] X— _ /X~ ? ~ ! /' ~ =j /'_ / — _° >j j ] % jK /jW _ ! /j ± v/' = j _ ±= ~ ! ) q g ~ % j ±_ /X~ ? _ / Wj=XJ ? ^ — X? ~ = X/° !~ ± /' j *+o’ E u E c ±jJ X~? ~ ! /'j g - Z j ] % j ± X— j ? / j/Ah B XJ h mm'h

UWh kq!2;U62Y^*V m2^2b^„; m*^*

x !/j ± /' j K _ ~ ± X— j /j ± — ~ W ^ j [ _= j]%~=jW /~ /'j s hc k j 1 )m) >j_— * X/ [ _= — ~ ; jW /~ /'j q u > j_— * [ ' j ±j /' j j!!jK/= ~ ? X/= % j ±!~ ±— _? K j [ j±j — j _ =^ ±j W ^ = X? J _ > j_— ~ ! mcs k j1 j jK /±~ ? =h 4 ' X= > j _— j ? /j ±j W /' j W j /j K /~ ± = XW j[ _° =h )jh %j±%j? EW XK ^ _ ± /~ /' j W X±j K /X~ ? ~ ! /' j * ^ _ ± /\ X> j ±= T BXJh a 'h 4 ' j K _ ~ ± X— j /j ± ±j =% ~ ? =j [ _= — j _ =^ ±j W _= _ !^ ? K /X~ ? ~ ! ± h /' j W X= /_ ? K j > j /[ jj? /' j X— %_K/ % ~ X? / ~ ! /' j % _ ±/XK j = _ ? W /' j _ X^ — X? X\ j W !±~ ? / !_Kj ~ ! /' j W j /j K /~ ± h

4 ' X= 5L(b*Y [ _= % j ±!~ ±— j W X? = /j% = ~ ! v K— h [ X/' /' j > j _— % _ ±/XK j = j ? /j ± X? J /' j W j /j K /~ ± _ / K f s h % ±~ > X? J /' j K j ? / ±_ ±jJ X~ ? ~ ! /' j K _ ~ ±X— j /j ±* _?W _ / G s mhc _ ? h % ±~ > X? J /' j > ~ ^ ? W _ ±° _ ±j _ >j/[ jj? /' j K j ? /±_ _ ? W /~ % ±~ [ = ~ ! /~ [ j±= h 4 ' j >j_— =% ~ / [ _= _ > ~ ^ / a ] a K—E♦ X? /'j=j — j_=^ ±j — j ? /= h 8 =X?J

/' j X? !~ ±— _ /X~ ? ! ±~ — /' j ^ % = /±j_— > j _ — K ' _ — E> j±= h /'j j ; j? /= K ~ ^ W >j =^>W X; XWjW X? /~ =— _j±XhjhhEo >X?=h

4 ' j mcs k j 1 j j K /±~ ? ='~[ j±= W j % ~ = X/j W /' j X± j? j±J ° % ±X— _± X° X? ~ [ j ±= r h c _ ? W u X? /'j=j — j _ =^ ±j — j? /= h 4 ' j = j /~ [ j±= % ±~ > jW /' j =' ~ [ j ± ±jJ X~ ? = !±~— c c E u a y» T4 ~ [ j± r 'h &' a E m a &' *1$ T4 ~ [ j ± c ’ _ ? W ma s mrhr ■' T4 ~[ j± u ' h ±j = % j K E/X;j ° h _= =' ~ [ ? /? B XJ h r h

x ? j] _— % j ~ ! /' j ±j =^ /= ~ ! /' j =j — j _ =^ ±j E— j ? /= X= ='~[ ? X? B XJ h ph [ 'j±j /'j _ ; j ±_ J j = XJ ? _ ±j K ~ ±W j W X? 4 ~ [ j ± c X= % ~ //j W _= _ !^ ? K /X~ ? ~ ! ± h ! ~ ± j;j? /= X? [ ' XK' /' j j j K /±~ ? = j ? /j ±j W /' j W j E/j K /~ ± _ / X E s c — — T/' j ~ % j? = * ^ _ ±j = X? BAXJh p T> /' _ ? W XE E a W ac — — T/' j !^ XW ~ /= — B XJ h pT> ''h ±j=%jK/X;j° h

y j!~ ±j /' j X ± ± _ W X_ / X~ ? * /' j = XJ?_= ±j K ~ ±W j W X? =K_? = ~ ! /' X= /° % j [ j ±j % ±_K /XK _ ° X? W j % j ? W j ? / ~ ! 5W v? _ = X— X_ ± — j _ = ^ ±j — j ? / — _Wj [ X/' _ mhc — W j j % — ~ W ^ j * [ j ~ > = j ±; jW /' _ / /'j = XJ ? _ = ;_ ±XjW >° j== /' _? cR ~ ; j ± /' j j? /X±j W j % /' h 6 j K ~ ? EK ^ W j W !±~— /' X= ±j = ^ / /' _ / /' j _ //j ? ^ _ / X~ ? j ? J /' [ _= _ ±J j ± /' _ ? a s — h _ / j_=/ !~ ± /' j g j±j? 9 ~ ; XJ ' / W j /jK /jW >° _ L - 4 [ X/' _ J_== [ X? W ~ [ DnV* _ = ^ =jW X? /' j % ±j = j ? / j] % j±X— j? /h

q ~ [ j; j±* X? /' j — j _ =^ ±j — j ? /= — _ W j *3^2; /'j W j =K ±X> jW X± ± _ W X_ / X~ ? _ / ) v) _ K j_± ±j W ^ K /X~ ? X? /' j =XJ?_= [ _= ~ > = j ±; j W h 4 X? = ±jW ^ K /X~ ? — _ ? X!j = /= X /= j ! X? /'j Ux’!2 ~ ! /' j ± EW X= ± X> ^ /X~ ? ~ ! /' j K _ E~ ± X— j /j ± ±j =% ~ ? =j h 4 ' X= W X= /± X> ^ /X~ ? j ] ' X> X/= _ ) X?9 X? /' j ±j J X~ ? 5 # mc Eas K— h

mmt


.,- lk,·nur:n ,r J/. i \tJ<l frutr .snJ .I/rm. 111 f'lru k:,. B /.~ 7' · ::V,J:, d6- '.Y 71

f

I ••of a 20 N _,200 i IS 1--------1,---.,-,----1 1,oo i - Tower 5 ~ 10~

. .• l~l)(,C\' C .'1kt•a'\

ii 10~ "'

! 'I Towcr& ~.,; ,s:· ..

ffe. :1 ·-·" ! 1 ::i _.. .. ···------!

,..e------------=---0 i a r ! 20 :, ,~

~.un(l~Gc\'o·i Cepth1nccpper (X0 i

Fig. b. Ch. ... J."\:tor ;_:-..,"vflh:lr' 111 lli.: :-,-.J.:1 with l5U (.j..:\." .:~~ri.JrJ 1.11 .11tJ d1'!' .1,\,i:r-J.";\,: tEG~• ;rut~ u( tbc ..:ni.:ri:i .!~"t'"'h:I.! Ji th.: J1,.1L"\."10f J.DJ UI ;om.,: i,Jf lli h,,l\\\.~ b~ thi! Jh.n\·~nn~ .:l'\.'1r1..,.Cb , b I. ~"'e t...--:,.l fot i.kta.d.,.

,mum <l~"\:urs at .1 larger Jc:pth (t, 1.-m \,:rsm J mll. This JS a ,:onS\.~U,:n~-.: of th,: Lit.:r.11 bromkning uf the pri>lil.: as the ~h,mcr,; Jc,·dop in Ji:pth. Thc lallc:r f.:-.iturc: 1:. 1llustr.1tc:J 111 Fig. 5. wh1,:h ,hJ\\S

the Lucr.11 Jos.: proriks at thn:c Jitforc:nt J.:pths: 5. 10 and 15 1.-n1.

Tl:,: longuuuinal dos.: prnliks ~h,m1: 111 Fig. 4 an: a reasonabk approxima1ion of those that nuy be cxp,.-.."t.:d .1it.:r Ill }t:'.lrs of LHC opcratior. at J.:sigr. luminosity for th.: ;,,1 - 4 - 5 n:gu,n of 1h.: C\IS .:,pc:rim.:n1 lcf Fig. 111.

J,:!. Et~rrmenta/ J.·tt:clor ,wlLI

Aft.:r th,: e1lorime1c:r muuulc: ,~.-us e.,pos.:J to Ille: 0.5 GcV LIL beam. Jt wa., moved to th.: H4 beam. wher.: the c:lfc.-cts on its pc:rfornuncc wen: mi:asun:J using a b.:am of 150 GeV c:lcctrons. This bc:am ~len:J the Jclc:(."\Or sideways. i.e. pc:rpc:ndicular to the: direction of the: quartz tihl..'1'S ( Fig. ~I. Thi: ,-alorimc:tc:r response: was mc:a.sur,'ll as a fum;tion of :. the distan~,: bc:twc:c:n th.: irnpac:t point of the: partick-s and 1hc: aluminized front fa,:c of the Jc:tcctor.

This :-scan \\·.is performed in s1.:ps of I 1."lll, with the be-am particles cntc:ring the detc:ctor at y = O. probing thc central n:gion of th.: c:ilorimctcr. and al y = 1.5 011. probing lhc: boundary ar..-.1 bc:1w~"Cn the: L"t:ntr.11 anu top rows of towc:rs. The bo:an1 spot was ab.iut ~ x 2 Lm1 in lhcse mc::isun:m,'flls. Using

118

the: mf1Jrm.1t1,m from 1hc: up~m:am b.:-a:n c:hamb.:n. th.: ,.:\L"tlU ~-..mlJ be subui\id.:J mto ,:nailer •y.:: bu~.

The: 150 Ge\' .:l,'\:tron shm\,:rs Jc:posu.:d th,:ir .:neri,:y pnm.inly m Tow.:rs 6. 5 anJ 4 in th.:sc: m.:;L,ur,-n1.:n1~. Tl1;.:s.: t11wi:r.; rrr,b,:d th.: sh11w.:r r,:gion, from 5.5-•J.~ _\;, 1T,1w.:r "'· 9.>l~.\I .\;, (fow.:r 51 and 1~.9-16.6 X, rTo\\.:r 4;, resp..'1.:ti,c:ly. as shown in Fig. 6.

An .:.,ampl.: 1Jf thc r,...,uh, ui th,-:;.: m.:-a.,un:mcnh i., ;h1Jwn m Fig. i, where the .1\1:r.ig.: signal r,"l.:oru,'ll in T owc:r 5 JS plolteu as .1 fw1 ... 'tlon of:. for l!\ents m w-hic:h the ek..."lrons enter.:u the ,.ktc:c:t•>r .11 y - 0 5 mm (th.: opc:n S<JU..ll'I.-S III Fig. i'1b11 and r ~ :!O :!5 mm uhe full Jot.; 111 Fig. 7(bll. n .. -spc!\."ti\d~-.

lkfore the: irr.iJiJti,.m, 1hc: signab n:.:ord .. -J in scans or this t~ po: were practically inuc:pcndcnt of :. In a similar m.:-.uuremc:nt made with ;1 1.5 m Jc:cp module. we obscn.:d that the signal> \aric:J by l..:ss than 5':'D over the emir.: Jeplh. We: conduded from this result that th.: attenuation k-ngth was larger than 10 m. at lc:ast for the C.:rc:nt..w light Jcll'Ct.:d by a P'.\IT \l,ith a glass wmdow [3), as w;,..-<l in the prc,;cnt c::\p,:rim.:nl.

However. in the: mc:asun:mcnts rnaJ.: <1/i.:r th.: dc:scribc:J irradianon at LIL a dc:-ar reduction in the: signals \l,as obs~:rved. Tlus n:tluction mamft.-sts it.self in lh.: 3/,upr! of the :.Jistrihu1ion of th.: i:alorimc:1.:r rc:sponsc:. This distribution cxhibit-1 a kink in the r.:brion : = 15-:!0 ~"lll.

h1 }vN<vR** —0 q] : h1 ? ± i NS N0 qS\ , N<vB <* k>01B I : / o [/r & jN,j® 22*

c s s

1 OO

GOO6 G OO

ass

mss aasx W_/_ 8 — j± c

* * ^ e ¥¥C * 2oT * 2Bn N

2hrag Ee

,j%/' X? K_~±X— j/j±* 5 TK—'

! /J r 4 ' j _ ; j ± 7 / ± K — K~~z X? 4 X— j ± c ? ] U U ? z_ X — 7+ Y ~ ? ; ; //X' K9 ; /±/[ XU 7? /K ± /? j /' j z K / X ] / ~ ! e? /' j ± j / X? _ U U E dl U — — 7 ~ z l■ G U^ Hc — — * ±;=%jK/X; K ' q X / ;h^±C»±+ _ ± ; W±_R /? /~ J ^ XW j /' j jlj

B XJ h u =' ~ [ = /' _ / /' j ±_ W X_ /X~ ? j!!jK/= X?W^KjW >° /' j ) v) > j _ — [ j±j j ==j? /X_ ° X— X/jW ~ /' j _ ±j _ ± d aW K— h 4 ' j ± E =K _ ? = [ X/' mcs k j1 j jKE/±~ ? = ±j =K_ j W _ K j _ ± ± EW j % j ? W j ? K j ~ ! / X j 4 ~[ j±Ec ±j =% ~ ? =j !~ ± 5 EK as K— h 4 ' X= W j% j? W j ? Kj [ _= = /±~ ? J j ± — /' j K j ? / ±_ ±j J X~ ? T ; E s c — — ' /' _ ? X? W Xj ±jJ X~ ? ~ K _ /j W a s Ea c — — _ > ~ ; j /' j Kj? /j± * [ ' XK' ' _ W ±jKj X; jW K ~ ? = XW j ±_ > ° j== ±_ W X_ /X~ ? h

T? ~ ±W j ± /~ * ^ _ ? /X!° /' X= j!!jK/* [ j — _ W j _ X? j_ ± X/ ~ ! /' j 4 ~ [ j ± Ec ±j =% ~ ? =j h £eW X? /' j ±jJ X~? 5 # v!#mc K — h ~ ! /' j /° % j

B ' & * • € * L T ] C S 2 '

4 ' j j ] % j ± X— j ? /_ W _ /_ [ j ±j =^ > W X; XW j W X? /~ X E (VUb2( U ~ ! c — — h ±_ ? J X? J !±~ — G # E m s — — /~ G f ac — — h B ~ ± j_K' =XKj* /' j j] % j±X— j? /_ 5L W X= /± X> ^ /X~ ? [ _ = /X/j W /~ w * h T v ' h 4 ' j ;_^j ~ ! /U'!X h /' j ? ~ ±— _ X\ j W = ~ % j ~ ! /' j W X= /± X> ^ /X~ ? X? /' j ±jJ X~ ? 5 d mc K— * X= = ' ~ [ ? _= _ !^ ? K /X~ ? ~ ! G X? B XJ h Z!_'h

U x ± E W XK K + 8 K /X? j W _ = _ K ~ , X] /X^ ? ~ ! ± j ! X / = X? [ ' j ' /' j mmu > j _ — % _ ? X K * = K ? /K ? hX /' j K _ ~ ± X— j /j ± X? /' j ±j J X~ ?

E m s — — ; d #c — — h E c % X— K ± d — — h j /K h h _ = Q jXK±E — X? K /X > ° / ' j ^ % = / ± j _ — W ? x K ' ^ — > K ±= h

4 'j =_ — j !XJ^ ±j _ =~ ='~[ = /' j X? /j J ±_ /j W ±_ EW X_ /X~ ? W ~ = j X? /' j =j lE=IXKj=h W j /j ±— X? j W !±~— /'j w k Z u = X— ^ _ /X~ ? = ~ ! /' j W ~ =j % ±~ /X j = h 4 ' j ±j X= _ K j _ ± K ~ ±±j _ /X~ ? > j /[ jj? /' j ? ~ ±— _ X\ j W = ~%j ~ ! /'j ±j =% ~ ? =j W X= /± X> ^ /X~ ? _ ? W /' j ± _ W X_ / X~ ? W~=j _ KK ^ — ^ _ /j W X? /' j K ~ ± ±j = % ~ ? W X? J _ ±j _ h 4'X= K j_±° =^ J J j= /= /' _ / /' j ~ > =j ±; jW K ' _ ? J j X? /'j ±j =% ~ ? =j W X= / ± X> ^ / X~ ? X= _ W X±j K / K ~ ? = j * ^ j ? K j ~ ! /'j X?W^KjW ±_ W X_ / X~ ? h q ~ [ j; j±* X/ = ' ~ ^ W _ =~ >j %~ X? /jW ~ ^ / /' _ / /' j ±j X= ?~ ~ ? j E /~ E~ ? j K~ ±±j E=% ~ ? W j? Kj > j /[ jj ? /' j X? W ^ KjW W ~ ; j j;j= TBXJh t T> '' _ ? W /' j ; _ ^ j „3 !o*!' TB XJ h t T _ + h v ! X?W^KjW ±_ W X_ /X~ ? X= X? W j jW ±j =% ~ ? =X> j !^ ± /' j K ' _? J j X? /' j =~%j ~ ! /' j ! X> j ±♦= ±j =% ~ ? =j K ^ ±; j * /' j ? ±j_E/X;j° =— _ W ~ = j = Tj hJ hh _ = X? W ^ K j W X? /' j ±jJX~? ° l mhc _ ? ' =jj— /~ ' _; j _ W X= % ±~ % ~ ± /X~ ? _ /j ° _ ±J j j!!jK/h 6 j [ X K~ — j > _ K9 /~ /' X= % ' j? ~ — jE? ~ ? X? Z j K /X~ ? nhnh

RWRW >U6’V*Û„Y(

RWR \W hu (U6!V2 6^YV2V6 j ' _ ; j = X— ^ _ /j W /' j j!!jK/= ~ ! /' j X?W^KjW

±_ W X_ /X~ ? ~ ? /' j — j _ =^ ±j W j ] % j ± X— j ? /_ W X= /±X> ^ E

mmb


:2 .V ,14.-J,,,nn ,r "'- I -'••rl l,u,r .-I .\l,tk III l'hu R,:, B 1!11 · :1J11: ., M-- 7/1

soo -----------------.Jso,-----------------. _ 400

:)

~

~ JOO Cl .; ;;; g E 200 -g <U u

100

-~ -····· -: ............. ..-a-'-JOO

zeo

220 • All Jaia 1,m er :i

... • . . . . . . . . .

. . .

I-~- ~ = :._, !.~ uun· ... ,"!\al-= "' • ~ I ~" 1 I '." ~ 0 :i; lllfU. ~'l!Jld - !!'-• - !.II.\ L

o ..__ _______________ ,ao"----------------' 0 10 I 5 20 25 30 35 0 5 '0 15 20 25 jQ

Depth in calorimeter. z (cml

f"r~ 7 TI1e: .i-.cr.i~"'C "'~JJ in Tv-...:r ~ n.·u,n.kJ 1n .:·""·uh -.-·uh i.:k"\:tfltrU ... ·11t..:nn~ 1hc Jc:ti.'\,;h.)f :n the n.~11..·ru ,· - n < mru .inJ ,. - =u .!5 mm. :l.":lpc."'\.:t1H.·I~ fh1.: .. .zr. ... "Jo JR:' Jr.--.-n to ~u:J.: rhr.: ~c

Fig. -' sh,,ws th.11 the: r.1diauon etfc:cts indu~-.:J bv the LIL be-.tm w~re esscnuallv limttcd to the an:-.1 : < .::o cm. Thc: :-s.:all.i with 150 G.:V ekctrons n...,·i:.1kd a d.::1r :.Jep,:nJc:nix of tli.: T 011,1:r-; rc:sponx for : ,_ 10 ,:m. This dL-p,:ndc:nL--c: was stronger m the L"l!r.tral rc:gion ty ~ I} 5 mm I than in tlu: n:giun IOCLtc:d :!0--15 mm above the: ~--c:ntc:r. which had m.,:i\ c:d cull.iidc:rably l.::.s radiation.

In order to quantify this effect. we maJ,: .1 hnL-ar lit of the To,.,er-5 n:spon-.:. R,. in the: l'\."gion : ..,. I~ 15 i:m. of the type:

-~- .:; ~ p, - I'! . :. ( lj

The: c:cp.:rimc:ntal dab w·:n: subdivided into _1·

slit"l.'s - of 5 mm. ranging from y ~ -10 mm to y = ::s mm. Fer i:-.tch slice. the: c.,pcnmental :distribuulln was titted tll Eq. (I). The \-alue llf ?!/Pi. the normalized slope of the distnbuuon in the region : < 15 cm. is shown as a function of y in Fig. sra,.

' A .r~ic~ a J.:linal ;io J ,-oU..:tk>n of .:wnts m ,.ha.:h th.: 114 bcun parta.:b ,-ntcr,-.J 1h.: .:ak>nn1L-t..-r in ilk: n:g,on -10 mm~ .t· r: -S mDL -5 mm ..... •·< O mm. .:t..:. • .i:. Jci..-r. auncd by !Ii.: 11p,1n.-:un dttli .:humb.-r ..

119

The s.im.: tigure also ,h,lws th.: mtc:gr.1tc:d r.1-dia11on d,l"<! in these y-sli~i:s. detemuncJ from the: EGS4 simulatillns of the: dos.: protilc:s. There is a cl.:-.1r ,orrdatiun bc:twa:n the: 11urm.11i.LL-d sl,>(X of the: n:spon.s.: d!!itnbuuun and the: raJiation dose: .1ccumuLuc:J in th.: com:spondir.g an:-J. This dearly suggots that th.: obso:r.L-d chang.: in the: n:sponsc Jl!ltributilln i.s J dinxt .:ons«:4uc:mx of the: induced r.1ctiation. Howc\.:r. II should also bc: point .. -J out tlut there i,, no onc-to-,.,n.: .:orresponJc:n.:c: lxtwc:,;:11 tile induL-.:J J,-....: lc\·ds I Fig_ l!lbl) and the ..-alue of P'!/Pi (Fig. S(a>). Ii mduccd rJdiation i.,. indci.-d re.ponsibl.: for the diange in the: slope of the: fiber"s n:spon.,;.: 1.-urve. thc:n relatively small doses (e.g .• as induced in the region _.. > 1.5 L"lll) SC."'l."111 lo ha\e a Ji,,propurtio11atdy large: c:ITect. We will com,: back to this phc:mmic:non in Section 3.3.

3.1. Simu/utiuns

J.J. / . .-1 simplr: mud.:/ We: have: simulat .. -J the dfcxts of the: induL-cl

radiation on the measured cxp,:rimcntal distribu-

1 Nv5>R0^ : N q ] [ h1 _ K i [S <0 q*% Q] N ]> B X? iU ! X±] X ! i hU p N ]dc' r r E p n

■G =__N

m [ + ■

a *_o

hI/. e

A O x s s c / d ' j e =qjXJ'/ X? K_~±X—j/j±h ° TK—«

B/oUh ±/h L XK x /U ±? /u9KKXX lvK%K _ X' K o E /' U /? > ^ /_ U ? _ / /' j _ CK !U 7 " K ; XXXhA? — K EK± UzO?_)9 — K ^ + ^ ±_ X /? ’2 UUK± c A_ U _ ? z /' j /? /j E X±^XK8 ± _ 7 ^ / 7 ~ ? z j [ h z K /K ± — — _ ! ± ~ — w X Z 9 /— ^ X_ /X~ /^ X> X h _+ _ ^ X( /X_ ^ ~ ! / ' j ■ U ~ X^ K ~ ! /' j X— % _ K / % ~ X? / _ /' j K A9 ^ !~ ~ U

/X~ /X 7 ~ ! /' j K _ ~ ±X— j /j ± ±j =% ~ ? =j — /' j K~ ? /j] / ~ ! _ = X— % j — ~ W j /' _ / [ _= j _ ± Xj ± W j ; j ~ % jW /~ = /^W° ±_ W X_ /X~ ? j!!jK/= ~ ? /'j % j ±!~ ±— _? K j ~ ! =K X? /X_ /~ ±E >_=jW /X> K ± W j /j K /~ ± = D4hZzh v? /' X= — ~ W j WXj ~K_ ~== X? XJ ' / /±_ ? = — X= = X~ ? X= % _ ±_ — j /j ± X\ j W _=

" " g 0 " *' V g * Zj~[ ' j±j VUoP X= /' j _ //j ? ^ _ /X~ ? j ? J /' _ / _ W j% /' 5 X? = XW j /' j K _ ~ ± X— j /j ± _ ! /j ± /' j W j /j K /~ ± '_= ±jEKjX;jW _ ± _ W X_ / X~ ? W ~ =j , Xj oo i$ ±j % ±j = j ? /= /' j _ / E/j ? ^ _ /X~ ? j ? J /' X? /' j _ > =j? Kj ~ ! ±_ W X_ /X~ ? h 4 ' j ±_ W X_ /X~ ? = j? = X/X; X/° ~ ! /' j W j /j K /~ ± X= — j_=^ ±jW > ° /'j ; _ ^ j ~ ! /' j % _ ±_ — j /j ± \h x =— _/ ;_^j ~ ! j K ~ ± ±j = % ~ ? W = /~ _ =— _ ±_ W X_ /X~ ? =j?=X/X; X/° TXhj hh _ _ ±J j ±_ W X_ /X~ ? ' _ ±W ? j == 'h v? ±_ W X_ /X~ ? W _ — _ J j = /^ W Xj = ~ ! % _=/XK =K X? /X_ /~ ±= * U [ _= /°% XEK_° !~ ^ ? W ~ > j ~ ! /'j ~ ±W j ± ~ ! _ !j[ /X— j= m s U A - ±_ W ♦ m K — A m Dt Vh

w *h Ta' ? j J j K /= /' j [ _;jj?J /' W j % j? W j ? K j ~ ! ±_ W X_ /X~ ? W _ — _ J j % ' j? ~ — j? _ h v / X= [ j 9?~[ ? /' _ / /'j _ / /j ? ^ _ / X~ ? j?J /' ~ ! * ^ _ ± /\ !X>j±= W j E% j ? W = ~ ? /' j [ _; jj? J /' ~ ! /' j XJ ' / /±_;j X?J /' ±~ ^ J ' /' j — _ ? W =~ W~K= /' j W j /j ± X~ ±_ /X~ ? ~ ! /'j /±_ ? = % _ ±j ? K ° ±j =^ /X? J !±~ — X~ ? X\ X? J ±_ W X_ /X~ ? h 4 ' j = ' ~ ± /j ± /' j [ _; jj? J /' * /' j — ~ ±j =j?=X/X;j /'j !X>j±= _ ±j h

q ~[ j;j±* X? /' X= = /^ W ° ~ ^ ± % ± X— _ ±° X? /j ±j = / X= /' j j ] /j? / /~ [ ' XK ' /' j (U4Y*V( !±~ — /' X= K _ ~ ± XE— j /j ± _ ±j ^!jK/jW > ° /' j ±_ W X_ /X~ ? h 4 ' j ±j !~ ±j * ~ ^ ± J ^ _ X= /~ j = /_ > X= ' _ ; _ ^ j ~ ! \ /' _ / _% % Xj = /~ /' j g j ±K? 9 ~ ; XJ' / / ' _ / X= J j ? j±_ /jW X? ~ ^ ± !X>j±= _ ? W /±_ ? = !~ ±— j W X? /' j L - 4 = X? /~ j jK/±XK =XJ?_=h x ; _ ±Xj /° ~ ! !_ K /~ ±= =^ K' _ = /' j =% jK /±^ — ~ ! /' j g j±K? 9 ~ ; XJ'/* /' j [ _; jj? J /' W j % j? W j ? / / ±_ ? = E— X== X~ ? /' ±~ ^ J ' /' j J~== [ X?W~[ ~ ! /'j L - 4 = _ ? W /' j [ _; j j? J /' W j % j ? W j ? / * ^ _ ? /^ — j!!XKXj?K° ~ ! /'j=j L - 4 = _ ± j /' ^ = X— %XK X/° !~ WjW X? /~ /' j ; _ ^ j ~ ! j ~ > /_ X? j W X? /' X= = /^ W ° h y jK_^=j ~ ! /' X= * /' j =j?=X/X; X/° ~ ! ~ ^ ± = /^ W Xj = X= X— X/jW /~ /' j [ _; jj? J /' X? /j ±; _ !±~ — umms /~ -5' ?— h

w*h Ta' _ =~ _ = = ^ — j = /' _ / /' j ;_ ^ j ~ ! \ X= X? EW j % j? W j ? / ~ ! /' j _ % % Xj W ±_ W X_ /X~ ? W~=jh v? /' j ±_ W X_ /X~ ? ' _ ±W ? j == = /^ W Xj = ~ ! % _=/XK =K X? /X_ /~ ±= * !~ ± [ 'XK' /'X= — ~ W j [ _= Wj; j ~ % jW * /'X= /^ ±? j W ~ ^ / /~ >j _ ±j _ = ~ ? _ > j _ ==^ — % /X~ ? h q ~[ j;j±* _= [ X >j ='~[ ? X? /' j !~ ~[ X?J * X/ X= _? ~ ; j ±= X— E% X!XK_ /X~ ? [ 'XK' X= ? ~ / ;_XW !~ ± /' j j!!jK/= X? W ^ KjW >° X~? X\ X?J ± _ W X_ / X~ ? X? /' j /°%j ~ ! * ^ _ ± /\ !X>j±= /' _ / _ ±j /'j =^ > 7jK / ~ ! ~ ^ ± =/^W°

8 =X?J w*h a X h /' j _ //j ? ^ _ /X~ ? j?J /' ~ ! /' j * ^ _ ± /\ !X>j±= K _? > j K _ K ^ _ /j W _ / _? ° %~ X? / X? =XWj /' j X±±_W X_ /j W K _ ~ ± X— j /j ± ~ ? K j /' j ;_ ^ j ~ ! \ ']= >jj? j =/_> X='jW h y° K ' ~ ~ = X? J _ ;_ ^ j /~ ± \ ~= _ = /_ ± / X? J % ~ X? /* ~ ? j — _ ° K _ K ^ _ /j /' j ;_^j= ~ ! /' j _ //j ? ^ _ / X~ ? j? J /' .5nS _ ? W h !±~ — /'j=j * /'j ±EW X= E /? > ^ / X~ ? ~ ! /' j K _ ~ ± X— j /j ± ±j =% ~ ? =j /~ j j K /±~ ? =' ~ [ j±= h y° K ~ — % _ ± X? J /'j=j ±j =% ~ ? =j K^±;j= /~ /' j j]%j±X— j? /_° — j _ =^ ±j W ~ ? j= * /' j ;_^j ~ ! \ — _ ° > j W j /j ±— X? j W j — % X±XK _ ° h 4 ' X= X= /' j — j /' ~ W [ j ' _; j ^=jW X? % ±_ K /XK j h

4 ' j = X— ^ _ /jW ±j = % ~ ? =j K ^ ±; j= [ j±j ~ > /_ X? j W _= !~ ~ [ = h 4 ' j g j ±K ? 9 ~ ; XJ' / % ±~ W ^ KjW _ / _ K j ± /_ X? W j % /' 5 _ ? W / ±_ % % j W X? = XW j /' j !X>j±= [ _= =%X/ X? /~ /[ ~ K~ — % ~ ? j ? /= * [ X /' j * ^ _ !±_ K /X~ ? = J ~ X? J /~ /' j ± XJ ' / T E X h = /±_ XJ ' / /~ /' j L - 4 ' _ ? W /~ /' j j!/ T E 5W /~ /' j _ ^ — X? X\jW ! ± ~ ? / j? W ~ ! /' j !X>j±='h 4 ' j % ' ~ /~ ? = X? > ~ /' K ~ — % ~ ? j ? /= [ j±j /±_ K 9 j W X? = /j%= ~ ! s hc K— ~ ? /' j X± [ _ ° /' ±~ ^ J ' /' j !X>j±h v? j;j±° = /j % * /' j XJ' / X? /j ? = X/° [ _= W X— X? X=' jW >° _ !_ K /~ ± j ] % E s hc *hp A\ ♦V* [ X/' /' j ~K_ _ / /j ? ^ _ /X~ ? j?J /' i / E o _ / W j % /' U j ] % ±j ==j W X? K— h

) XJ ' / /±_; j X? J / ~ /' j j!/ T L5W =jj BXJ h a' [ _= _ ==^ — j W /~ ^ ? W j ±J ~ _ ? X? /j? = X/° ~== ~ ! a s N l ^ % ~ ? ±j !j K /X~ ? ~ !! /'j — X± ±~ ±j W !X>j ± j ? W h 4 ' j ;_^j ~ !

FEO


19

1,. ... 8 ·-. ~ 0.~

_,:;===========::======::::: ::i ! !. ! ;» ,a -

I ! - .. "' I t ;

.. -= ·l ,---..,-----,-----------"--

1:l S .)1 ,, :.s. He,gt,t ,n caJOrlmeler. y (cml

F1_:. :-4. f'!1c :11..-nu.lu1.-J >k~t"= uf the :.Jbtnbut11.tft Ji' th-,: .a'\\:t•

.. ~ .;.u,,nmt.:td' ~ m.:-.u,m.-J 1n r .. """""'f' 5 lj • .1.mJ thl: tnh:~a!1.-J r.:!Ju.lk.'!l J0>t.:. J..:t.:rnu.n.1."\J frum ELS 111ffluiatwrui tb1. 2:.

.a \~'11i.,u ._,f th&: , ".llu~ of th~ unpJ.:t p.n:u Ji th,.: ~kl..uon.,

!Ions of th,: L-;ik,n:n.:h:r rL-,,ponsc: m th.: ,:onh."\I of J simp!.: modd that was earlier J._•ydu~-d hJ study r.1Ji.11iun c:ITL-.:IS on th.: pcrforman..:c ..,,- ..:111111!.11,,rb""'--J tib.:r J.:1 .. -.:tur.; C:'-~)- In this mu<ld tit.: I0\.·.11 !u:.s m lil,'.ht tr.ms:111~,iun is rar.1me1c:riuJ .1.,

whc:re /[:; i:. th.: a1tenua11011 l,:ngth al d Jcplh : iruidc the i:alorimcter after thc: J.:tci:tor h.i.,, reL"l:IH:d a radiation Jos.: D1:;; t., r.:prL-,,.;nl3 tl1,: altc:nuati<.ln !c:ngth in th.: absence: of r.idiation. The: r.1Jiation scns1ti\·i1y uf th,: Jeuxtor is m.:-.a.surL-J by thc: value of the p-.1ramcter l. A small \·aluc of :r i:orr.:spomb to a small r.1di.1ti,m scnsiti\·i1y (i.e .. J larg1: radiation hardn.:ss). In r.1Jiation damage studies of plasu.: scin1illa1or.;, :r was 1ypi-1.·.tlly found lo b.: of lb.: order of a f .. ·w tim1.-s Io·' ~lr.1J· 1 1.-m · 1 [8).

Eq. C!I nc:glc:.:ts the 1,a.,.dength Jq,.:nJ.:no..-e of r.1dia1ion damage phenomc:na. It is well known that the anenuation lc:ngth of quartz fib,:n Jcpends on Lhc wavelength of the light travding through them and so Jocs the ,k1i:rior.11ion of thi: tr-.msparc:ru.-y resulting from ionizing r.1Jiation. The shorter the: wavelength. the more s.:nsitive tb: lib.:rs arc:.

120

73

However, in this study our primary interest is thc eittt:11t to wruc.:h the sii:rwl.s frum ~ ..:alorimcter arc: alTe1:tcJ by th.: r.1Jiatio11. Therefore. our goal is lo establi~h a \aluc of x that .ipplies to th,: ~kuv light that ts generated m our fibers and lransformcd in the: P~IT, 11110 d,:1:tnc.: signals . .-\ vanc:ty of factors such as the spectrum of the: C.:n:nk<.lv light. the wa\Cl..:ngth dep..-ndcnt tr.1nsntbs10n through the gla:-:. windo\\ of th.: P\IT i .inJ the ua\·den~h J ... -pcnJcnt quanrum dli,:11:n9 of th<.°><! P\!Ts an: thus 1111pli,:i1ly fcld1.-d into th,: \aluc llf l obtained in Lhis study. Ba.:-.111.-;.: .,, 11:is. the: \t.:r~,iun1y ,,f our studies L~ lnmtL-J tu th.: wa\elc:ngth intc:nal from .mo hJ (l{J() nm.

Eq. 1.!1 also .issumc:s that the \11lue .,f x ts inJepcn,knt of the .1ppheJ r.1J1.11wn J,,s.:. In thc r.1dia1i,,n hardno..-,,s slud~-s of pl~ti,: ,cmtillalurs . for wh10.:h thi, :noJd was dcvdop..-J_ thb 1um1.-J out to 1-..: a re-.1.,or.;1l>lr.: ,L..,,umruun. Hm\i....,cr. ,1s will be shown in the fol101\mg. rt is .in ,ivc:rsi:nplilio.:atiun 1\hi,:h 1:. 1:,>1 \aliJ f,,r th,: ,tf .. -.:ts indui:1.-d by romzmg radiation m th,: 1ypc of quartz tibcrs 1~1 .ire II:,: subJ1.-.:t ,,four ,md~

L',im; Eq. 1.:1. the .11tenuat1011 lcn~lh vf 1hc quaru rib.:r, ,:.1n bc 1..·.1kula1c:J at .1ny p,11111 rnsiJc th.: 1rr.1Jiat,-d .:alorimct..:r ,,n.:c th,: .,.ciluc ,,f 1 ha., been .:st.ibli,hcd. B~ di,,tJsmg a \alue f,,r :.r: J.5 J starting prnnr. oni: may ,:-.ikulalc the values of thc Jltenuauor: li.:ngth h:; ar:J_ frnm tho.:. the :.Jislnbull(ln of th.: ,:-.1lonmc:1er n:,-porue 10 ..:kctn>n shower... By companni; thcs.: response 1.'lll",CS to th.: ..:.~penm.:ntall~ rrn:a.urcd one:,. the ,alu,: of :z may be dct1.-rmincd 1."lllpinc-.11!y. This is the mcthu<l \\,: ~\e 11><.-d in pr.ii:ti ... -e.

The sim11la1eJ re:spons.: 1.-urves wc:re obtained as follows. The C.:n:n.lr.ov light pru<lm;cd at a ~,main depth : anJ trJpped inside the fiber.; was split into two components_ with equal fr.i..:uons going 10 1hc right ( ~±. ,Lr.tight 10 the P\IT) anJ tu th.: lc:ft ( - :. lo the: .iluminizc:d front end of the fibers). Thc photons in both ,:omp,.m ... -nt!> 11,erc 1r.10.:k.:d in ,,cp:; of 0.5 o.:m on their way through the tiber. In ,:y,:ry step. lite li~hl intcnsily was Jimini:it:cd b~· a f.1i:h1r c:.~pi- 0.5,' /,: );. 11,·uh the: lo.:-.11 anenualllln kni,'lh II: J at depth : ,:.,:pressed in cm.

Light traveling to Lhc left ( -:. see Fig . .!I wa.-1 assum1.-<l to unJ.:r£o an inl.:nsity luss of :lJ':, upon rc:tlc:ction off the ruirron.-d tiber enJ. The \alui: of

pu X1 BdR>R0N* N ] qp ( W R N ] 9R00 Q°— :> qN k>0NB I 0 < o .W" » ■ , *ZM

’’U

h X

s acs

,j%/' X? K_~±X—j/j±* N XK—7

BXJh b h Z X— ^ _ /j W ±j = % ~ ? = j K ^ ± ; j = _ ~ ? J /'j K j ? /±_ ] ^ _ ~ / /' j

X— ^ ^ /K ; ' K _ X A! — [ /K ± h ! /U z / ± / j ! / ? X ;_^jU ~ ! /' j % _ ± _ — j /j ± $

B ~ ± K ~ — % _ ? X~ ? * /'j K ; % ~ ± /— K ? ^ ; ?[ _ =^ ±; W K ^ ± h K h K ~ ? CK U — j— l ? ~ — ^ ^ j 8 h <1 ='~;>~ _ = [ j Z jj /j / I■U ;Xj / ^ >

ih* [ _= /_ 9 j ? _= E s — h y ~ /' _ ==^ — % /X~ ? = [ j±j >_=jW ~ ? j] /j?=X;j j E=K_?= [ X/' _? ^ ? X± ± _ W X_ /j W — ~ W ^ j ~ ! j] _K /° /' j =_— j j?? X%~; X/— ? DnVh

v? /' X= [ _°h /' j ! ±_ K /X~ ? ~ ! /'j g j±K? 9 ~ ; XJ' / /±_ % % j W X? /' j /X> j ±= /' _ / ±j_K' jW /' j L - 4 [ _= K_ K^ _ /jW h y° ±j % j _ /X? J /' j Wj=K±X>jW % ±~ K j W ^ ±j !~ ± _ _ ±J j ? ^ — > j ± ~ ! % ~ X? /= _ / WX/4j±j?/ W j % /' = TK'h /'j = X— ^ _ /jW ±j =% ~ ? =j K ^ ±; j [ _= ~> /_ X? jW h

w ] _— % j = ~ ! = X— ^ _ /j W ±j=%~?=j K^ ±; j = ~ > E/_ X? jW X? /' X= [ _° _ ± j =' ~ [ ? X? BXJh sh 4 ' j =j K^ ±; j= [ j±j ~ > /_ X? j W ~ ? /' j >_=X= ~ ! /' j W ~ = j % ±~ !Xj C=Sa T_ ? W X/= K~ ? =j* ^ j? Kj= !~ ± /' j XJ ' / _ / /j ? ^ _ /X~ ? K ' _ ±_ K /j ± X= / XK = ~ ! /'j X>j±= _ K K ~ ±W X? J /~ w *h Ta '' _ K K ^ — ^ _ /j W X? /' j 6 X? /j±;_ s E c — — h _ ; j±_J jW ~ ; j ± /'j !^ ] E[ XW /' ~ ! 4 ~ [ j± c T=jj B XJ h n'h 4 ' X= [ _= W ~ ? j /~ = X— ^ _ /j /'j j ] % j ± X— j ? /_ K ~ ? W X/X~ ? = ~ ! /' j ± E =K _ ? /' _ / [ _= K_±±XjW ~ ^ / _ ~ ? J /'j K j ? /±_ _ ] X= ~ ! /' j K _ ~ ±X— j /j ±h 4 'j = X— ^ _ /jW K^ ±;j= =' ~ [ ? X? BXJ h s [ j ±j ~ > /_ X? j W [ X/' ] ; _ ^ j = ±_ ? J X? J !±~ — n U vs /_ X? j W !±~— /' j 4~;;j±Ec K _ ~ ±X— j /j ± = XJ ? _ = * X= =' ~ [ ? X? /'j =_— j !XJ^±jh

4 ' j ; j ±/XK_ =K_j ~ ! B XJ h b '_= ?~ _ > = ~ ^ /j — j_? X?J h B ~ ± /' j j ] % j ± X— j ? /_ W _ /_ * /' j ±j = % ~ ? =j [ _= ? ~ ±— _ X\ j W /~ v !~ ± /' j ±jJ X~ ? Wjj% X? = XW j /' j K _ ~ ± X— j /j ± /' _ / [ _= ^?_/4jK/jW >° ±_ W X_ /X~ ? h B ~ ± /'j = X— ^ _ /j W K^ ±;j=* /' j ; j ±/XK_ =K_j W j ? ~ /j = /' j

% ±~ > _ > X X /° /' _ / XJ' / Jj?j±_/jW _ ? W /±_% % jW X? /' j /X>j±= _ / _ K j ± /_ X? W j% /' e ±j _ K' j= /' j XJ'/ W j /j K E/~±h

4 ' j = X— ^ _ /j W K^±;j= j ] ' X> X/ /' j =_— j K ' _ ±_ K E/j ±X= /XK !j _ /^ ±j = _ = /'j j ] % j± X— j ? /_ W _ /_ e _ — ~ ±j ~ ± j== !_ / ±j = % ~ ? =j !~ ± ±E;_^j= _ ±J j ± /' _ ? a s K— h [ 'j±j /' j ±_ W X_ / X~ ? j!!jK/= >jK~ — j ?jJXJ X> ° =— _ _? W _ — ~ ±j ~ ± j== ~J_±X/'— XK W j K X? j ~ ! /' j ±j E=% ~ ? =j ! ~ ± XJ' / % ±~ W ^ K jW X? /' j _!!jK/jW ±jJ X~? ~ ! /'j K _ ~ ± X— j /j ± T ± d as _ X' h q ~ [ j ; j ±* /'j 9 X? 9 =j% _ ±_ /X? J /' j =j /[ ~ =jK/X~?= ~ ! /' j ±j=% ~ ? =j K^ ±; j _ % % j _ ±= ~ >j ~ K_ /jW W jj%j± X? = XW j /' j W j /j K /~ ± /' _? /' j = X— ^ _ /X~ ? = j_W ^= /~ >jXj;j /K f a s K— j ] % j ± X— j ? /_ ° * ;j±=^= ± = m s K — X? /' j = X— ^ _ E/X~?='h

v? /' j K ~ ? /j ] / ~ ! /'X= — ~Wj* ~ ? j [ ~^W K ~ ? EK^Wj ! ±~ — /' j ~>=j±;jW ±EW j% j ? W K ? Kj X? /'j !X±=/ vvv K— /' _ / 7 _— ~ ^ ? /= /~ Tn Eu e h ms u

- ±_W K — C q ~[ j;j±* [ 'j? [ j ±j% j_ /jW /' X= _? _ ° =X= !~ ± ~ /' j ± ±jJX~?= X? [ ' XK' ±E=K_?= ' _ W >jj? % j ± !~ ±— j W TXhj hh !~ ± W X/!j ±j? / XE=XKj=h [ 'j±j /'j X? W ^ K j W W ~ =j= [ j±j — ^K' =— _j ±' * [j !~ ^ ? W /' _ / K ~ ? = XW j ±_ > ° _ ±Jj ± X ;_ ^ j= [ j±j ?jjWjW /~ W j =j ? > j /' j — j _ =^ ±j W ±j=%~?=j K^±;j=h B ~ ± j ] E_— %j h X? /' j ° E= XKK _ ±~ ^ ? W l■ E a K— h [ 'j±j /'j W ~ =j W XW ? ~ / j]KjjW ms - ±_W h ] ? jjW jW /~ >j X? EK±j_=jW >° _ ? ~ ±W j ± ~ ! — _ J ? X/^ W j X? ~ ±W j ± /~ Jj/ _ ±j _ = ~ ? _ > j W j =K ±X% /X~ ? ~ ! /' j j ] % j±X— j ? /_ ±j E=% ~ ? =j K ^ ±; j h x ? W h _ = >j!~±j* /' j = X— ^ _ /X~ ? = [ j±j ~? ° K _ % _ > j ~ ! ±j% ±~ W ^ K X? J /' j ±EW j% j ? W j ? K j X? /'j !X±=/ % _ ± / ~ ! /' j Wj /jK /~ ±* [ ' j ±j _ = /' j j] % j±XE— j? /_ j !!jK /= ~ ! /' j X?W^KjW ±_ W X_ / X~ ? j] /j?WjW — ^K' W j j % j ± X?=XWj h

4 ' j % _ ±_ — j /j ± ] X= /'^= K j_± ° W ~ = j W j% j? W j? /e ±j _ /X;j ° =— _ W ~ = j = ~ ! ? W X_ / X~ ? K _ ^ =j ±j _ /X;j° _ ±Jj j !!jK/= ~ ! X? W ^ KjW XJ'/ _ / /j ? ^ _ / X~ ? h x / W~=j= ~ ! _ !j[ — j J _ ±_ W = * /'j ±_ W X_ /X~ ? ' _ ±W ? j == X= ? ~ / — ^K' > j / /j ± /' _ ? /' _ / ~ ! /'j >j=/ % _ = /XK =K X? /X_ E/~ ±= •Zzh > ^ / _ / — ^ K' ' XJ'j± W ~ =j = /' j ±_ W X_ /X~ ? ' _ ±W ? j == X= K~ ? = XW j ±_ > ° >j //j ±h 4 ' X= W ~ = j W j % j? EWj?Kj _ = ~ j ] % _ X? = =~— j ~ ! /'j ~ /' j ± j] % j±X— j? /_ % ' j ? ~ — j ? _ ~ > =j ±; jW X? /'X= = /^ W ° * X? % _ ± / XK ^ _ ±

■ 4 'j _ > =j ? K j ~ ! ~ ? jE/~ E~ ? j K~ ±±j =% ~ ? W j? K j > j E/[ jj? /' j — j _ =^ ±j W =~%j= 3M*!] TB XJ h t T_ '' _ ? W /' j K _ K ^ _ /j W ±_W X_ /X~ ? W ~ =j = X? /' j ; _ ±X~^= ° E=Xjj= TB XJ h t T> ' 'h Z— _ W ~ =j= % ±~ W ^ K j _ ±j _ E/X;j° _ ±J j = ~%jh

FEF


i4 ,V .llula,r,n,itJJ. / .Vw/ burr .,,.,I .1/,ilr.., /'Irr< Rr, B Iii~ •_'fJII!, M-T!J

. .

; • ..... ,_...._....._ •• ,t 1 "'I ; . ll • I t') 4, \!&-,. ,.. :

• U • ,f 10 t ""-t ~- I

•• - •. u. \ln,J ·-•' . ·------ -------o.·-----------------' 1) S 10 I~ :0 ::5 JII

~h 1n .,:alcn1nc1cr.1. \OYIJ

f•i;. 9. s,mw,11 .. -J n.-.poiu.: ,..,,., .. .aJ.,nc lh< ,,,nu-~ ........... t!i.: 1rr.1d:tatL-J ,.1L.,rmi,.r1.-r. f1.tt JttL:rea.1 -..i1u.."" ll( th&: ~•r:irn-:l~r 1

hn l.'.oltl~fbl_'R. the ~,r-,.-rmk:11t.1..U:, :n.,.~.oun:J ,:ur.c. _,;l'""1.:'·

~rlll~ m1r.1l.lhb:1.i. b "10-.n .1.1 w~U '-~ 1.:tl l,,r J~Lub

/., was uk.:n .c; .:u m. li"th .1s.>ump11~11:.:; w.:r.: ba.)<.-.J on c.,rcn,;1,c: :->4.-.llb with an umrr.1Ji,1t.:J ml>duk of c:,actly the -.amc: i:nmpo,iuon [3].

In tht, way. the: frai:lll'll of th,: C.:n:nko~ light trapp,:d in the tib.:rs that n:-.1..:h~-d th,: P \IT w~ cakular.:d. 13y n:pe-.itmg the: Ji:si:rib.:tl prlll.-c:dur.: for a large: number of point.sat Jilf.:rc:nt Jc:pths I:). the: simul;uc:d ri:spunsc: cun·c: \\a.s llbtainL-d.

E.,.impk,; of simulatL-d rL.,.p..>n>.: cun.:s lJbtain.:d in thi.s way arc: shown in Fig. 9. Tl1c:sc: cunL-s wen: obuinc:d \JD the: basis of th.: dose: prolilc: 01 :i I ;ind its c,;n.>c:tjucni:cs for thc: light auc:nuation char.1L"1c:ristics of the libcrs accordini: 10 Eq. (.:!I) aa:umu!atc:d in the: .v intcn-:11 0-5 mm-: a\"er.tgcd o,·cr the full .t-wiJth of Tower 5 (see Fig. 3J. This was done to simubtc thc apc:rimc:nwl condition:; of the :-s..--an that wa.s carrii:d out alon!:! the: central ,L'tis o( the c-.tll>rimc:tc:r. The: simulated L-Un.:s shown in Fig. 9 wc:re obtamL"ll with 2 ,aluL~ ranging from 3" to-' to 5 x 10-' ~lrad- 1 cm-•. For i:omparison. thc c:xpc:rim.:ntal ;-roporu.: curve for y"" 0-5 mm. obtainc:d from the: T "wc:r-5 1.-alorimetc:r -ignals. is shown in the: \itme tigun:.

The: vcrti.:al sale: of Fig. 9 has no ;ibsolutc rnc-.iuing. For lhc c:xpc:rimc:ntal Jara. the: r.::;pons.: was normalizc:d to I fur the region Jc:cp il15idc: lhc: ... ilorimeter that was unalTc:ctc:d by radiation. For the: sinmlatc:d L-un·c:s. the: v.:nii:al SL-ale: dc:n<>tc:s the

121

probability that light gcneratc:d and trappc:d in the: tibc:r.i al a ccruin dc:pth : n:achcs the light dc:t.:ctor.

Th.: simulatL-d curv<.-s c:xlubu the: s;imc: char.u:tc:ristic fc:-.itures as the: ~'tpc:rimenta! datJ: a mere ur less !lat n:sponsc: for :-,·aJuc:s l;irgL-r th.in .:!U L"lllwhcrc: the r.idiation c:tfc:.:ts bo:omc: neghgibly small .1nd a more or less il1garithm1c dc:clinc of rhc: n:•pon.sc for light produL-i:d in the atf<."\.--ts'll region .,f the: 1.-.ilorimc:tc:r (: < 2U L1lll. How,:\c:r. th.: kink scpar.itmg these: two S<."\:tiuns uf the n:spon.s.: ,-un·c: arpcars to be loc-.iti:d Lkc:pc:r inside the: Jctc:ctor than th,: simulations le.1d us tlJ behc:,·e I: :::: 20 ~-n1 .:xpc:nm.:ntally. ,c~us : -::: lO ,-n1 in th.: s1mul.1-1ions1.

In the: i:ont,:.'l.t of thi,; modd. 01:c: \\oulJ i:011-duJc: frum th.: l•lh.:n<.-d :-J.:pcnd,-n,.: m tl:c rir.l Ill cm that z ;um,unL, h.J i 3--4: , JO • ~lr.1J ' .. m '. How~'"'"· "hc:n we: rc:p,:;11,:d this .11wly sis for other rcg1or.s in wluch :-scans h;id ~-c:n pc:rformc:d I 1.c .. fur Jitferem r-slic.:s. whcn: the mJu .. -..-d Jo,,._-,, wcr.: mud1 ,nulkr,. \\C: f,.mnJ that i:L,nsid.:r.1hly lar!,,<er z \,ilue~ \\,:r.: n,-..·,.k'll 1,, <l~si:nbc: th.: measurL'll rL-,.pl>n.s.: 1.-urv~~- fl.)r ..-,. ample. in the: y-slicc around _1· ~ .:! cm. \\hen: thc: d\Js.: did llllt c::\CL'c:d 10 \lrad. z nc:,'llL-d tu bc: mcr.:ased by an 0rdcr llf magnitude: in ordc:r 10 gc:t a rc-.1.><>nablc: d~~riplion of the: c:.,pcrimc:nlal n:Spl>OSC: i:urvc:. And. as b.:forc. th,: simulations wc:rc .,nJy ,-.ipabk of rc:proJu,,ng the :-J..-p,:nJem:e in the tint part of the: J.:r.-..1or. \\hc:rc:.u the: C:\P,:nm.:nt;il dT,-cts of lh,: inJuL-..'ll radrati,111 at.:ndc:J much J._-.:pcr in,;iJ..-.

The par.imc:tc:r i ts thus clearly dos.: Jc:pc:ndent: rc:lativdy small dosc:s of r"Jdiation ,.iu.s.: rc!Jtivdy Lirgc: c:tfo:ts .,r indl.lLi:d light alt.:nuatii,n. ,\1 dosc:s ,,f a fow m,-garads. the radiation hardnc:ss is not much bellc:r thJn th.it of the best plastic ,;._;ntillator.. (8 ]. but at mui:h h1ghc:r dosc:s th.: rJJiatmn hardn ... -ss is considerably b.:ucr. This dose: dcpc:ndc:nc,: also .:xplains S<>me of the: other .::cpc:rintental phenomena obsc:rvc:d in this study. in particular:

• The abs.:n<.-c o( one-lo-one: corrc:spond.:nL.: bc:tw· ... \:n the: mo:-.isurL-d slop<.-s t>:/Pt I Fig. l!(;ilJ and the: ..:ak-ular .. "11 radiation doses in the \'arious _Mlk\."S ( Fig. S(bll. Small J0sc:s prudu1.-.: a n:lativc:ly lar!,'t! slope.

h1 B<v <<R q S » ! q< : 1 ^ U i NSR0 R * $ X i / ! x h N* N>61 I'< o i+U. Z jbVj■ *N6*"M pc

■ 4 ' j !_ K / /' _ / /' j 9 X? 9 X? /' j j ] % j ± X— j ? /_ ± E = K _ ? X= ~ K _ /j W W jj% j± X? = XW j /' j K _ ~ ±X— j /j ± /' _ ? X? /' j = X— ^ _ /jW ±j =% ~ ? =j !^ ? K /X~ ? = TB XJ h b 'h 4 ' j _ //j ± [ j±j K_K^ _ /jW ~ ? /' j >_=X= ~ ! _ /X]jW ; _ E^j ~ ! X _ ? W /' ^ = /j ? W j W /~ ^ ? W j ±j = /X— _ /j /' j ±j _ /X; j ° = /±~ ? J _ / /j ? ^ _ / X~ ? j!!jK/= K _ ^ = j W >° /' j ±j _ /X;j ° =— _ W ~ = j = X? /' j /_ X= ~ ! /' j ) v) E— W ^ Kj W j j K /±~ ? =' ~ [ j ±= h

4 ' j =j j!!jK/= =^JJj=/ / ' _ / _ — ~ ±j W j /_ XjW = X— ^ _ E/X~ ? ~ ! /' j j] % j±X— j? /_ W _ /_ * ~ ? /' j > _ = X= ~ ! _ — ~ W j X? [ 'XK' /' j W ~ = j W j % j? W j ? K j ~ ! X X= ± XJ ~ E±~ ^ =° X— % j— j? /jW * — XJ ' / X— % ±~ ; j /' j _ J ±j j — j ? / [ X/' /' j j] % j±X— j? /_ ±j =^ /= h

DLD C„(2 m2!2Ym2Y^ YxY^^3U2’^^’Y(Q ^ ± j] % K±X— j ? X_ ~ > = j ±; _ /X~ ? = =^ — — _ ±X\ jW _ /

/' j j ? W ~ ! /' j % ±j ; X~ ^ = =^ > =j K /X~ ? * ^ _ X/_ /X; j ° K ~ ? !X±— /' j ±j=^ /= ~ ! =j; j ±_ ~ /' j ± J ±~ ^ % = [ ' ~ ' _; j ±j % ~ ± /j W /' _ / /' j ±_ W X_ /X~ ? E X? W ^ K j W W j !j K /= X? J _==j= _ ±j [j W j =K ±X> j W >° _ %~[ j±E_[ W j % j ? EW j ? Kj ~ ? /' j W~=j j;j= Db ’h v? ~ ±W j ± /~ j = / /'j ; _ XW X/° ~ ! =^K' _ W ~ =j W j % j ? W j ? K j X? — ~ ±j * ^ _ ? E/X /_ /X; j W j /_ X !~ ± ~ ^ ± K _ ~ ± X— j /j ± * [j ±j % j _ /j W /' j

n

X ■ j]%j±X— j?/_ W _ /_ Q K _ U Q 8 ]l , &® Y l _ f shsms 8 E A ■

u Tj±_'B XJ h msh Z X— ^ _ /j W ±j =% ~ ? =j K ^ ± ; j = _ ~ ? J /' j K K ? / ? X ^ X = ~ ! X> j X ± ± _ W X_ /j W K ^ ~ ? ±~ j /K ± h !~ ± W X! j ± j ? K ' ~ ±j j = ~ ! /' j T W ~ = j W j E% j ? W j ? /' % ^ ? — j X j ± ± h B ^ ± K ~ — % ^ ? = ~ ? h /' j K /% j ± X— j ? /_ = — j _ =^ ± j W K ^ ± ; j X= W X^ [ ? _ = [ j h Z j j / j _ / !^ ± W j /_ X= h

= X— ^ _ /X~ ? = ~ ! /' j X>j± ±j =% ~ ? =j K^ ±; j W j =K ±X> j W X? /' j % ±j ; X~ ^ = =^> =jK /X~ ? [ X/' _ W ~ =j W j % j ? W j ? / U ;_^j _ = !~ ~[ =e

XT, ' f ] * *, E dno

4 'X= X= j * ^ X; _ j ? / /~ ±j% _K X?J /' j j] % ±j == X~ ? ^ =jW /~ K _ K^ _ /j /' j ~K_ XJ'/ _ / /j ? ^ _ / X~ ? j?J /' i X ± I Tw *h Ta'' >°

6 j ; _ ±Xj W > ~ /' /'j ;_^j= ~ ! _ ? W ? X? ~ ±W j ± /~ ~ > /_ X? /' j > j =/ _J±jj— j?/ [ X/' /' j j ] % j ? — j ? /_ W _ /_ h Z ~ — j ±j = ^ /= ~ ! /'j=j = X— ^ _ /X~ ? = _ ±j =' ~ [ ? X? BXJ msh /~ J j /' j ± [ X/' /' j j ] % j ± X— j ? /_ ±j =% ~ ? =j K^ ±;j ~ > /_ X? j W !±~ — /'j 4 ~[ j±Ec ;XJ?^= X? /' j ±E =j_? _ ~ ? J /' j K j? /±_ _]X= ~ ! /' j X± ±_W X_ /j W K _ ~ E±X— j/j± TXhj hh /' j dU#c — — X E=XKj' Z X?Kj [j _ ±j ~? ° X? /j ±j=/jW X? /' j (* ’!2 ~ ! /' j ±j =% ~ ? =j K^ ±;j * /' j W _ /_ _ ±j % ~ //j W ~ X _ ~ J _ ±X/' — XK ; j ±/XK_ =K_j * /'j _> =~ ^ /j ; _ ^ j ~ ! [ 'XK' '_= > jj? K' ~ =j? _ ± > X E/±_ ±X° h _ = X? B XJ h bh

v! [j K ~ — % _ ±j /' j=j ±j=^/= [ X /' /' ~ =j !±~ — B /J h bh [ 'XK' [ j±j ~ > /_ X? j W [ X/' _ K ~ ? = /_ ? / ;_ ^ j ~ ! _ C

[j =jj _ = % j K /_ K ^ _ ± X— % ±~ ; j— j? / X? /'j ±j % ±~ EW ^ K /X~ ? ~ ! /' j j ] % j±X— j ? /_ W _ /_ v? % _ ±/XK ^ _ ± * /' j 9 X?9 X? /' j ±j =% ~ ? =j K^±;j X= ? ~ [ =' X!/jW > _K9 X?=XWj /' j K _ ~ ± X— j /j ± * X? j]Kjj? / _ J ±jj— j? / [ X/' /'j j ] % j ? — j ? /_ ~ > =j±; _ /X~ ? =h 4 ' X= ±j!jK/= /' j !_K / /' _ / ±j _ /X; j ° l—_ W~=j=* =^ K' _ = /' ~ =j !~ ^ ? W >j°~?W /' j = ' ~ [ j ± — _]X— ^— * =/X K_^ =j _ ? ~ E/XKj_>j X? K ±j_ =j X? /' j XJ'/ _ / /j ? ^ _ /X~ ? h

P ~/ =^ ±% ±X= X? J ° * X/ /^ ±? = ~ ^ / /' _ / /' j %±jK X=j ~K_ /X~? ~ ! /' X= 9 X? 9 X= ;j±° =j? = X/X; j /~ /' j K ' ~ XKj ~ ! /'j % _ ±_ — j /j ± YW B ~ ± _ J X;j? K ' ~ XKj ~ ! YW /' j ;_^j ~ ! H±l K _ ? _ [ _°= >j K ' ~ =j ? =^K' /' _ / /' j =~%j ~ ! /' j j ] % j? — j? /_ ±j =% ~ ? =j K^ ±; j X? /' j _!!jK/jW ±j J X~ ? X= [ j ±j % ±~ W ^ K jW h q ~[ j;j±* /' j (U52 ~ ! /' X= ±j J X~ ? * Xhjh /'j W j % /' _ / [ ' XK' /' j 9 X? 9 ^ ~K_ /jW * W j % j ? W = ~ ? U W B ~ ± j ] _— % j * !~ ± Y L s hc h /' j 9X?9 X= ~ K _ /jW _ / ± f= mn K— h [ ' Xj !~ ± ? E s hta /'j 9 X?9 X= > _ ±j ° ? ~ /XKj_> j * [ 'XK' ±j!jK/= /' j !_K / /' _ / j;j? /' j j ] /±j — j ° =— _ W ~ =j = W j % ~ =X/jW ? j _ ± /'j ;j±° j ? W ~ ! /' j — ~W^ j K ~ ? /± X> ^ /j =XJ? X!XK_? /° /~ /'j XJ ' / _ / /j ? ^ _ / X~ ? h 4 ' j >j=/ ±j % ±~ W ^ K /X~ ? ~ ! /' j %~ =X/X~ ? ~ ! /' j 9 X?9 T_ / ± R mb K— ' [ _= !~ ^ ? W !~ ± Y L s hp h _ ? W /' j K~ ±±j =% ~ ? W X? J ~ % /X— ^ — ; _ ^ j ~ ! _F [ _= s hsms h 4 ' j = X— ^ _ /jW ±j =% ~ ? =j K^ ±; j !~ ±

FEE


.... 14,·lu.rlfl •. , .,I I .Vru:/ ,...,, .,,,J Jl,nlt u, ,.,,_.. &t B r.,7 r _"Ill);: 1 IW>--·., 7S

• The fact that the kmk in the c:tp.:rimcntal :-scan i3 located dcepcr inside the calorimet.:r than in th.: simulat,-J n:sporu,c fum .. -tion.s (Fig. 9). The latter ,1,cre ,-akula.11.:J on the b.bis of a lixcJ valu.: of 1 anJ th\15 tcnJc:d to unJo.:1'1:5timalc the n:lativdy strong ath:nuatiun cff,:,:15 ciu:.cd by the: n:latndy small Ju:,c:s in the ta1b of the LI L-inJu~-J d.-.:trun sh.,,,o.:rs.

The;,.: .:!Teet,; ;u~g.:st that a m"rc Jctail.-J simulatiun of the r.:."tpc:rimcn1al Jara. on the basis of a mo<lcl m "'h1.:h th.: Jos.: Jep.:nJ,:n,-c of 1 is rigorously impk·mcnlc:J. nught impro,,: th.: .1gr,-.:ment 1Aoith th,: o:'tp.:rim,·ntal n..-sults.

J.J.:. Das~ J.·pmd.·nt mudt/1<·,uiuns Our o.:'tp,:rimc:ntal .,b;crvation.s summarm:J at

th.: c:nJ of th,: pn..-v,,,u;. sut-.... -.:11,,n q11alit;1ti,dy cunfim1 the r,-suh,. of !>C\eral oth,:r :;ruup~ "Im h;m: r.:port,-J that tho.: r.1Ji.1tio11-inJu..:,:J Jdi..-.:b in i;l.issc:s an: wdl Jc:..:rib.:J b~- a p,>wi:r-l.1w J,:pcn· Jcn.:c: "n th,: Jos..: t,..-..,:b ('JI. In urJcr Ill t..:-.t th,: ,·ahJ1t) .,f ,u.:h a J,,,,: J,:pcnJ.:m.-.: in rn"r,: ,11iantitat1,e Jct.iii f..,r our o.:-.1lori:nctcr. \\C rcpcatc:J th,:

I '"r l;_., r

;;;i

IL~t V 7~

,; 0 0~ ....

f I

~ I) 5t = I

I ;: ,ur .§ I i "" "'/

u.z

.--- ····· ; ............ ..~ ...... ······., .... . ·····.··~-:-'llaa,)OCO

--~ ••• ···:.:~fJQ:11., :. •• •• ~·,..o,"" eou~o.;ui...=c

•·-~ .-:ao'!'-.::c:-a

')

, .. :·, --

ltl

I• npm"""""1da>uj : C (.C :a 0.00', 0.4l~ i '• 1t=o.01ou•1-· I i • a -:-OIJI-S Iris; I

IS .:o .:s )0

I.IL-mi

fii;.. ID. Sunut..h.'J n=;roru.: .:uoo .a.lon11 lb,: ,:i:,unl u1> of tho: lff.uJulOJ ,_.l,·,nmd,T. for J1!T.:n:nl ,h,"°"" of 1111: (J..,_., J.:. pcnd.:DO punmct.:r z. Fur ,.,mpim,on. ch~ ,.,ix-r1111C111Jll~ m-=ssun."1 cun~ ~ Jiu"'a .u *dl- So: ta.t fuc J.i.'1.uU.

122

simulations of 1hc fiber ~po~ cunc dcscnbcd in the pl"C'\ious subsecti"n wi1h a dos.: dependent 2 ,,due: a.,; follow!!:

(3;

This is equiulent to r.:placin!!! the .:xpn:5sion uscJ lo c-Jkulate tl:c l.x-JI lighl attenuation length ft:l t Elf. (~)) by

I I , • - ~ - • :z,,Dl:l . fl: I lo

Wc vari.:d both th.: ,·alucs of z, anJ n in ord.:r tl.l obtain the b...-sl J.!IT•-Cntcnt with the e:1:p,:nmcntal Jata. s.,me n:,ults of tho.: ,imul.iu"ns arc shown in Fig IO. togelhcr with the e,pcnm,:ntal r--spon.sc .:un,: obtaml.-d from th..- To\\,:r-5 ,ignal,. in the: ;. ....:an al11nc tho.: • .:ntr.11 ;m, ,,f tho.: 1rr.1Ji;11,-J call>rim.:tcr 1i.~ .. the 0-5 m:u _1·-~liL1.:). Sim:,:,,,: .m: onl:,intt:rL-st,:J in the ~lwp<' ,,f the r.-sp,m,..; ,un,:. the J.1t.1 arc plotlt • .J un a lugarithmi,; wrti,-JI ~.ik th.: .1b,.1lut.: \·aluc of wh1,h has bc..-n ,hos,:n arbitranly. as m Fig. 'I.

If w,: .:om par.: tl:L-so.: r.-sults w11h tbo-.: from Fig. 'I, whi.:h w.:r,: ubtain.-J with a 1:on)IJII\ \Cilu,: 11f 1.

\\C: >(."C a ,pc.:l.1L-ular 1mpr0\,:m.:nt in the r.:proJu,.:tiun of th.: ..:'lp.:rimo:nt;1I Jata. In par11.:ular. the lmk. m tht: rc:.pons.: .:un c IS r.ow sluftc:J bad, inside 1he \."al<,rimc:tt:r. in t:.'tcdlenl agr=cnt with the c,pc:rimc:nt.il ub~nJUor~~- ThtS r.:lkcu 1he fJ<.:l th.it rdati..-dy ,null J~-s. ,u,;h .i.,; those fuunu "'-"'·or.J th,: showc:r nuiimum. sllll cause: .i notk~.iblc: in.Te-JS<: in the: light .iuc:nuation.

~ot ,urpri.\ingly. 11 turns cul 1h.1t the precise lo..-atiun ,>f this k.inl is very >l."ltSiti\..: tu tho.: choi.:o.: of th,: par.im,.:ti:r n. Fnr a givc:n .:h,11..:t: uf n. th,: ,·aluc: .,f 14 c-.in always be chosen !>l1Ch that the slope: of 1he ap.:rime111al n:sponsc .:unc in the aff.-.:ted n:gion is well r--produc.:d. Howt:\·cr. th.: si:e .,f this region. i.e. the Jeplh ,ll which th,: kink i:l lllCat,:d, Jep,.:nds on n. For c.umph:. for n -= 0.5. lh.: kink is l=il.:d al : :::: I 3 ,·m, w ht!,: furn ~ 0.82 th,: kink is ban:ly nol~i:-.iblc. "hich ret1 .. -cts the fa.:t that .:,·en 1h.: cxu-emcly small Jos..-s Jc:posit.:d nc:ar lhe very end .,f the module: con1ribu1c Sl!,!Jliticanlly lo th.: light a1tenuation. The best reprodu\."tion of !he position of lhe kink (al:::: 19 cml wa, found for n = 11. 7. anJ 1hc curn:sponJing "ptimum ..-aluc: of :z,, was 0.010. The simulalc:J response cune for

p r h1 B <v <> R * * 0 N <%B [ WN€p N*1<0 q*% , N<>B U / ku * I'0J o [(WJ xr E p n

U # s hs m s s “ C )jh /' j K ^ ± ; j ~ > /_ X? j W !~ ± ~ ? X? EW ^ K jW XJ ' / _ / /j ? ^ _ /X~ ? W j = K ± X> j W >°

) ? E E ~ h Q Q,XhEXAmmh Tcm]°n m i?X= ±j % ±j =j? /j W >° /'j ~ % j ? K X±K j = X? BXJh msh v / X= ±j — _ ±9 _ > j /' _ / _ W X±jK / — j _ = ^ ±j — j ? / ~ ! /' j W ~ = j W j % j ? W j ? K j ~ ! /'j „!Ûb*V ^;*Y(!*;2YbG ~ ! /' j / X> j ±= ° Xj WjW _ ;j±° =X— X_ ± ±j = ^ / X? /' j [ _;jj?J /' ± j EJ X~ ? ih j ' ~ [ X'j ~ > = j ±; j W ± _ W X_ /X~ ? W _ — _ J j j!!jK/= [ W _ !!jK / /' j % j ± ! ~ ± E— _? K j ~ ! /' j * ^ _ ± / i X> j ± K _ ~ ± X— j /j ± X? /' j ) q g j ±_ h

Q ? K j /' j ±j _ /X~ ? =' X% > j /[ j j ? /'j ±_ W X_ / X~ ? W ~ [ _ ? W /' j ±j=^ /X?J X? W ^ K j W XJ ' / _ / /j ? ^ _ / X~ ? ' _ = > jj? j=/_> X=' jW * /' j ~ K _ _ / /j ? ^ _ / X~ ? j ? J /' ~ ! /' j /X> j ±= K _? >j K _ K ^ _ /j W !~ ± _ ? ° % ~ X? / X? = XW j /' j K _ ~ ±X— j /j ± * ~? /' j > _ = X= ~ ! /' j ~K_° _ K K ^ E— ^ _ /j W ±_ W X_ /X~ ? W ~ =j Tw * h dc'h 4 ' j=j W ~ =j= ' _ ; j > jj? K _ K ^ _ /j W X? J ±j _ / W j /_ X ! ~ ± /'j g - Z j ] E% j ± X— j ? / DvVh

B ~ ± j ] _— % j h BXJh mm = ' ~ [ = /' j W ~ =j % ±~ !Xj= _ / SP*' # nh u _ ? W ch _ = _ !^ ? K / X~ ? ~ ! W j % /' — = XW j /' j * ^ _ ± / i !X>j± K _ ~ ± X— j /j ± * _ K K ^ — ^ _ /j W W ^ ± X? J ms ° j _ ±= ~ ! ) q g ~ % j ±_ / X~ ? h 6 j _==^ — jW _ /~ /_ X? /j J ±_ /j W ^ — X? ~ =X/° ~ ! 3 G m ^ f m s s s > m !~ ± /' j =j K _ K^ _ /X~ ? = h

x = _ /° % XK_ ~> 7jK/ ~ ! X? /j ± j = / X? /' X= 9 X? j — _ /XK ±j J X~ ? * [ j K ~ ? = XW j ± _ vQQ k j 1 X/“ h [ 'XK' =' ~ [ = ^ % _ = /[ ~ cs k j 1 % ' ~ /~ ? = ' ~ [ j ±= X? /'j q B K _ ~ E±X— j /j ± h 6 j ' _; j = /^ W XjW /' j K ~ ~ ± X— j /j ± ±j = % ~ ? =j _ ? W /' j j? j±J ° ±j = ~ ^ /X~ ? ! ~ ± = ^ K ' ='~[ j±= * _ / A/iv f u _ ? W ch _ = _ !^ ? K /X~ ? ~ ! /X— j * _ ==^ — X? J _ K ~ ? = /_ ? / ^ — X? ~ =X/° h

4 ' j % ' ~ /~ ? ='~[ j±= [ j ±j = X— ^ _ /j W [ X/' w k Z u h B X± = / * /' j ±j =% ~ ? =j K^ ±; j ~ ! /' j /X> j ±= [ _= K _ K ^ E_ /j W _ = !~ ~[ =h Q ? /' j > _ = X= ~ ! /' j _ % % XK _ > j W ~ = j % ±~ /X j T=jj BXJh m m' _ ? W /' j W ~ = j W j % j ? W j ? / q ; _ ^ j=* /' j W j % /' W j % j ? W j ? / _ / /j ? ^ _ / X~ ? j ? J /' 'Aoa [ _= W j ±X; j W * ^=X?J w * h Tc ' h 4 ' j ? * /'j ±j =% ~ ? =j K ^ ±; j £AoU [ _= K_ K^ _ /jW X? /' j = _ — j [ _° _ = !~ ± /' j ± E = K _ ? = T=jj ZjK/X~? n hn ha h B XJ h m s 'h j]Kj% / /' _ /

s c y O mc 7 ± 7 ' n z .

,!/%/' ±U+gj K_z~K—_Xy± TK—U

B X" h m mh w hC% / h; K X X % ±~ ! Xj = /~ /' j q B K _ ~ ± X— j /j ± ~ ! g - Zh ■5)8 X/— _/KW X? ms = K _ ± = ~ ! % _ ? ? X? J * !~ ± E G/h E/ _ ? z l

X? /'X= K _ =j — ~ = / ~ ! /' j g j±K? 9 ~ ; XJ ' / [ _= _=E=^— jW /~ > j /±_ % % j W X? ~ ? j W X±j K /X~ ? v ■ ± h =jj BXJh a ’ _ ? W / ±_ ; j j W W X±jK /° /~ /'j L - 4 =h v? ~ /' j ± [ ~±W=* > _ K 9 [ _ ±W j — X//j W g j±K? 9 ~ ; XJ ' / ±j!jK/jW _J_X?=/ ^ % = / ± j _ — — X± ±~ ±= [ _= J X;j? _ =— _j± [ jXJ'/ /' _ ? X? /' j K _=j ~ ! /'j K E=K_?= h , X±j K / _?W ±j!jK/jW XJ ' / [ j ±j _ ==^ — j W ~ _ K K ~ ^ ? / !~ ± tsNh _? W a s N ? ~ ! /' j = XJ ? _ = * ±j=%jK /X;j ° * X? _ KK ~ ±W _ ? K j [ X/' — j _ = ^ ±j — j ? /= % j ±!~ ±— j W ~ ? _ W X!!j ±j? / % ±~ E/~ /° % j K ~ ~ ± X— j /j ± ~ ! /' j =_— j K ~ — % ~ = X / X~ ? Dnzh

v? /' j w k Z u = X— ^ _ /X~ ? = ~ ! /' j cs k j1 ° ='~[ j± W j ; j ~ % — j ? / * j ? j ±J ° W j % ~ =X/jW _ / _ W j % /' o X?=XWj /' j K _ ~ ± X— j /j ± [ _ = [ jXJ' /jW >° _ !_K /~ ± £AoaW /~ _ K K ~ ^ ? / !~ ± /' j j!!jK/= ~ ! XJ' / _ / /j ? ^ _ /X~ ? ±j=^ /X?J ! ± ~ — X? W ^ K j W ±_ W X_ /X~ ? h 4 ' j K _ ~ ±X— j /j ± [ _= K ~ ? = XW j ±j W _ — _== X; j > ~K9 ~ ! K ~ % % j ± l? /' j=E = X— ^ _ /X~ ? = * = ~ /' _ / ; _ ± X_ /X~ ? = X? /' j _ > =~ ±> j W T[ jXJ' /jW v j ? j ±J ° [ j±j ^ ? X*^j ° K _ ^ = j W >° /'j j!!jK/= = /^ W Xj W ' j ±j T _ ? W ? ~ / >° /' j j!!jK/= ~ ! =_— % X? J ! ^ K /^ _ / X~ ? = _ ? W ~ /' j ± !_ K /~ ±= W j /j ±— X? EX?J /' j = XJ ? _ = ~ ! ±j _ K _ ~ ±X— j /j ±=' h

Z ~— j ±j = ^ /= ~ ! /' X= = /^ W ° ~±j = ' ~ [ ? X? B XJ h mah v? BXJh ma T_'h /' j _ ; j ±_ J j K _ ~ ±X— j /j ± = XJ ? _ !±~— cs k j1 °= X= = ' ~ [ ? _ = _ !^ ? K /X~ ? ~ ! /X— j TXhjhh X? /jJ ±_ /jW ± _ W X_ / X~ ? W ~ = j ' * !~ ± % ' ~ /~ ? = j? /j ±X? J /' j * ^ _ ± /\ ! X> j ± K _ ~ ± X— j /j ± _ / 7±77 E u _ ? W ch ±jE=%jK/X;j° h B XJ h maT>' = ' ~ [ = /' j j!!jK/= ~ ! /' j _K EK ^ — ^ _ /X? J W ~ = j ~ ? /' j [ XW /' = ~ ! /' j =j =XJ?_ W X= /± X> ^ /X~ ? = h 4 ' j ' ~ ± X\ ~ ? /_ _] X= X= % ~ / /j W ~ ? _ =K_j X? j _ ± X? xNsm * [ ' j ±j h1 = /_? W = !~ ± /' j ? ^ — > j ± ~ ! °j_±= ~ ! ) q g ~ % j ±_ / X~ ? h x = — _° > j j]% jK /jW h

man


76

:z .;cc 0.010D-0 ~. i.e. the curve obtainc:d for an induced light ;1ttc:nuation described by

I I --=-~0.0IOD(d 1

• 1_51 I(=) /.,

is represented by the upc:n ~;n,:lc:s in Fig. 10. It is n:markable that a direct measurement oi the dose Jep..'lldc:ncc: uf th,: <•pci,ul cr<L•upurenq of the nbc:r.. ) idJ,,J a \·cry similar result in th.: wavc:lc:ngth region i. - -l50 nm. wh,-re our P'.\ITs n:ao:h,-d thcir rua.,imum -;c:r.sui,·it) [ IUJ.

.&. Comcqurncn for opcr.uion at lhc LHC

In thl!i s..-ction, we dcs.:rih.: how th.: obsc:nt.-<l radiatiun damage dTt."1:ts wul a.lTl:\:t the pc:rforman..-e of tl:e quartL tihcr ~-;1lurimcter in th,: LHC cr.1.

Once the rdauonslup b.:t"-c."<!n th,: rad1a11,m Ju . ...: and thc r.:suhing indut.-...-J light attenu.itwn has b.._.n c.-stahl~hed. the: llJC"al atlenuauun length of the lib.:rs can Ii.: ,-akulatc<l for any pumt U1Sidc the calunmctcr. ,m the: bass:. uf the locally ao:o:umulatc.-J radiatiun du,;,: tEq. 151). These: Josei ha\e b.-en ,-.ikulated III gn:al Jctail fur the Cl.IS e,penruent [I).

For c::umplc. fig. 11 shows the <lo~ profiles at :•1! -=- 3. -' .md ;_ as a function of depth inside the: qu:irlL tib.:r calunmc:t,:r . .10:1.-umulatc.-J Jurin~ JO years llf LHC <>pcratwn. We a.,.sum...J a total integrated lum111osuy of f :.r di = IUOO tb · 1 for these cakulauons.

As a typic-al obi.:ct <>f interest in th1S lunc:matic rc!:,.;on, we c.-unsiJcr a 100 GeY r.. which shuws up as two 50 GcV photon sho1Aoi:rs in the HF c:dorim.:tc:r. We: have: studic:d the t.-a.lorimctcr response and the c:ncrgy rc:solution for such showers. at !111 = -' and 5. as a function of time. assuming a con:.tant luminosity.

The phutun sho\!ocrs wc:re simulated 11ith EG~. First. the: response cune of the fibers \\"JS c-aL:ulatcd as follows. On the basts oi the applk·able d~ protilc: (sec Fig. 11) a.n<l the ,!use dependent z \·aluc:s. the dc:pth dc:pcnJent attenuation length I(=• was dc:nvcd, using Eq. (5;. Then. the: n.--sponsc c..sne RI=) was c:1lcul;1tcd in the sam.: way as for the :-s..-ans (sc:c Section 3 . .3.2. Fig. IO). except that

123

'"I !

••' f

............

j ·+ ... -·· ···-- ·--..... . I ···t·· .. ---·····--·-........ .

I ,- •, •• t •••

··· ...

• ,, ~ j

11 :;:J •'laS

I . ; ···1

' .....

··· .. ''\'-------.,---,-,----=,,'---,-,--,, O.olf'I .,.si,c:a catorrr..ater (cm,

''l'- 11. E.,p,:.:s..~ Jm,.: rrL•lil..-. ID ,h.: IIF ,.1l.>run.:t.:r .. r <:\IS . .A.1,.uruul.itL-J 1n lU ~i;.:a"' of r..1nranl,!. (l,r 'I ,;;. 3. -' J.nJ ~

in this ca.-;c: most ,,f th.: C.:renkov h~ht \\.ts .i.~

sumcd to be trapr,:d in one: Jm:i:uon t • =· ~-.: Fig. :1 Jnd trJ\c:k,J dirc.-.:tl! Ill the: P'.\ITs. In othc:r wunh, h.1d~warJ .:nutt,-J C.:r.:nkuv light rdk-.:t,-J against upstream mirrurs 11;1!; g1vc.-n a ~mallc:r \\<'l!!ht than in th.: ,.is.: lll the: :-scans. Dir,-ct Jnd rctl,-ct,,J light w,:n: asswn,,J lo a,;,;uunt for g11· , and :ir·. of the signals. n:,,(IC\:ti\·dy. in ac.-cordan,;~ with m·.:-a.,uremc:nts performed on a Jilf.:r~nt prot<>typc .:alorimeter of the: wme composition [J).

In the EG~ simulations of the 50 Gc:V , sho\!oer Jc:~·d<>pment. ener1,•y d.:pmit~d at .1 J.:pth; inside: th,: 1.-alurimctcr was \\cightcd by a factor R(=). to a'--count for the elTc,.:ts <>flight anenuaiion n:sultmg from induced radiauon. Th.: calonmc:tc:r was cun,iJ.:rc<l i! massi, c hloclr. •Jf copp,:r is• !ho'!·'

simulations. so that van:itions in the: ahs,,rb.:J (wc:igh1ctl1 .:n,rin w.:n: uni4ucly caUSc:d by the eff,-cts stuJi.:d here I and not by the etfo;u of sampling tlu1.-tuations and other fa'-"tors Jc:tcnnining the: signals of real caforimc:lc:rsl.

Some n:suJts of this study arc shll\\D in Fig. 1:. In Fig. l'.:lal. the: a,er.ige calorimet,:r signal from 50 Ge: V rs is ~huwn a:s a fum:tion uf time: I i.c: .. integrated radiation dose). for photons entering the: quartz tibc:r calonmc:tcr at 111[ -7 -' and 5. rcspa."ti,cly. Fig. l:?{b) shows the effects of the: act..smulating <losc on th.: wid1hs llf these signal distributions. The horizontal axis is plom:d on a scale: linear in ,\.oJ. when: N stands for the numb.:r of ye-ars ~,f LHC opcr.itiun. As may be c.-xpcct'-,J·

h1 }v5>R0<* 5] qN [ W R — N N*€<0 q*% d N N v <* k>61 I—1B o iz!r jVV'* 22*"t

p F #]< '

)QUh:u ■8 shbmE

/.h oa ~h7X/E h Nm hshpAo0B_9 h

c Q'hA

z shc n v'

? f u7 ? f c ■ms

LD3*P0E”;Nh

rmE

h! ’

X " /I ! *)© 1 v_ z "

9 ;'

vU 4’ f u XX f c

sm h m c m c mmm as ® s sm v hc v c

)qg °j_±= ^X?X?~=X/; f ms♦IK— e = Am'ms as

vEAX°h mah 4 ' j K h/% j ; j W K 7 ~ ? — j K E ± ± j l % ~ X^ j Th+► ~?8 j?K±J; oj=»hU^/^— X > / !~ ± 1X g61 i h j ? X j ? ? = X' j h E 7 ± A! X? ; Xj ± 7 / ©o E m h m A^?j^ X±/ mUm ^ ? K u ^ ? ? J ) q g ~ % K ± 78 ~ 0 7 X /' j ? ~ — X? _ ^ — X? X♦^ ' 4 ' j ' ~ ±j j ? ^ 8 7 7 ^ h + %8 h!jQ ~ ? x EK _ K X? jj ± X? h1 A Uh ±) X? ±> !~ ± !' j /^ [ ~ ! mhmmg ~ %j— /( h? Z j j gjX !~ ± zj/~X)Eh

/' j ±j =^ /= ;K^j [ X/' h1 N h [ 'XK' X= X? W XK _ /jW >° /' j !_ K / /' _ / /' j W _ /_ %~ X? /= _ ±K [ j Wj=K±X>jW >° = /±_ XJ ' / X?j= — /' X= !XJ^±jh

Q = ~ ± /' j X!j /X— j ~ ! /'j j = % j ± X— j ? h /'j K _ ~ E± X— j /j ± ±j = % ~ ? =j /~ cs kj1 p = ? ^ X; >j j]%jK /jW /~ W j K ±j _ = j >° _ > ~ ^ / n c & h _ / mo E c _ ? W >° _ > ~ ^ / m c ♦ E _ / ;] f u h _ = _ ±j=^ / ~ ! X?K±j_=jW XJ ' / _ / /j ? ^ _ /X~ ? X? /' j * ^ _ ± /\ /X> j ±= K_^=jW >° j ] % ~ = ^ ±j /~ X~? X\ X?J ± _ W X_ / X~ ? h 4 ' X= ±_W X_ /X~ ? [X _ = ~ X?K±j_=j /'j j ? j ±J ° ±j = ~ ^ /X~ ? * >° X?W^KX?J _ ? j ] /± _ /j ±— [ 'XK' X? !X±=/ _ % % ±~ ] X— _ /X~ ? X= X? W j % j ? W j ? / ~ ! j?j±J°h 4 ' X= /j ±— _ — ~ ^ ? /= /~ v v!N* !~ ± p # c _ ? W nhc®Ehh !~ ± .. # u h _ ! /j ± m s °j_±= ~ ! ) q g ~ % j ±_ / X~ ? * _ ? W _ W W = X? * ^ _ W ± _ /^ ± j /~ /' j ±j=~ ^ /X~? ~ ! /' j ^ ? X±±_W X_ /j W X? = /±^ — j ? /h

v/ X= X— % ~ ± /_ ? / /~ ±j_X\j /' _ / _ > ~ ^ / ' _ ! ~ ! /' j — j ? /X~ ? j W j4jK/= ~KK^ ±= W ^ ± X? J /' j !X±=/ °j_± ~ ! ~ % j ±_ / X~ ? * ~ ? j E* ^ _ ± /j ± j;j? ~ K K ^ ±= W ^ ± X? J /'j !X±=/ — ~ ? /' h 4 ' X= X= _ W X±jK / K ~ ? =j * ^ j ? K j ~ ! /' j W ~ =j W j % j ? W j ? K j ~ ! /' j ±_ W X_ /X~ ? ' _ ±W ? j = = % _ ±_ — j /j ± . W 4 ' j ±j _ /X; j ° =— _ X? /jJ ±_ /jW W ~ = j = ±jKjX;jW X? /' j !X±=/ ° j _ ± ' _ ; j _ W X= % ±~ % ~ ± /X~ ? _ /j ° _ ±J j j!!jK/ ~ ? /' j K _ ~ ± X— j /j ± %j±!~ ±— _?Kj h

v? /' j = X— ^ _ /X~ ? = Wj=K±X>jW X? /' X= =jK /X~? * [j ' _ ; j _ = = ^ — j W /' _ / /' j j!!jK/= ~ > = j ±; j W X? ~ ^ ± X ± E± _ W X_ / X~ ? = /^ W Xj = ~ ! /' j K _ ~ ±X— j /j ± % ±~ /~ /° % j _ ±j

/' j ~?° ~ ? j = /~ % _° _ ±~ j h q ~[ j;j±* X? % ±_ K /XK j /' j ±j [X _ =~ > j ~ /' j ± j!!jK/= /'_ / K ~ ? /± X> ^ /j /~ ±_ W X_ /X~ ? W _ — _ J j _ ? W X/= K~ ? =j*^j?Kj= ! ~ ± /'j g - Z — j _ =^ ±j — j ? /= h 6 j — j ? /X~ ? /[ ~ *^ K ' j/!jK/=e

■ 6 j '_;j _ = = ^ — j W /' _ / ~? ° /'j j— =' ~ [ j ±= J j? j±_ /jW >° *± ♦= _ ? W ~ /' j ± j j K /±~ — _J ? j /XK _ ° W jK_° X?J % _ ±/XK j = J j ? j ±_ /jW X? /'j ) q g X? E/j ±_ K /X~ ? = K ~ ? /± X> ^ /j m s /' j ±_ W X_ /X~ ? W _ — _ J j %±~!Xj=h v? % ±_ K /XK j _ =~ K' _±J jW ' _ W ±~ ? = K ~ ? E/±X> ^ /j h Z X? Kj /' j j? j ±J ° K_ ±±XjW >° /' j =j % _ ± / X EKj= X= /° % XK _ ° W j % ~ = X/jW X? _? _ ±j_ /' _ / X= — ^ K' _ ±J j ± /' _ ? /' _ / X? [ ' XK' K— =' ~ [ j ±= W j E% ~ = X/ /' j X± j ? j ±J ° * /' j W ~ =j j;j= X? /' j ' _ W ±~ ? XK K _ ~ ±X— j /j ± = j K /X~ ? _ ± j K ~ ±±j =% ~ ? W X? J ° =— _ j ± h q ~[ j;j±* XJ ' / J j ? j ±_ /j W X? /'j j— K _ ~ ± X— j /j ± =jK /X~? [ X _ = ~ ' _ ; j /~ /±_;j±=j /' X= > _ W ±~ ? XK =jK /X~? > j !~ ±j X/ ±j _ K' j = /' j L - 4 = _ ? W =~ — j _ W W X/X~ ? _ _ > = ~ ± % / X~ ? [ X X?j; X/_> ° ~ K K ^ ± h

■ 6 j '_;j XJ ? ~ ±j W ±j K~ ; j±° j!!jK/= X? /' j X ± ± _ W X E_ /jW !X>j±= ~ ± _ / j _ = / /' j ±jK~;j±° /' _ / ~ K K ^ ±= ~ ? _ /X— j E=K_ j ~ ? J j ± /' _ ? _ !j[ W_°=h 0 jK ~ ; j ±° !±~ — X± ± _ W X_ /X~ ? X= _ K~ — % XK _ /jW % ±~Kj==* W j /_ X= ~ ! [ 'XK' W j % j ? W ~ ? /' j /° % j _ ? W W ^ ±_ /X~ ? ~ ! /'j X± ±_ W X_ /X~ ? h 4 ' j j!!jK/= _ ±j _ =~ = /±~ ? J ° [ _ ; j Ej? J /' W j % j ? W j ? /h

mau


~ I.I

j t • ·" 1.0•. ;,,-

> l u 0 o.c;f-

l V", f

- 011l 'I, r

f f t 11.7~ .r.

-- p T]:::4:

~ TJ:::41 . --

- I .,'A

TJ = 5 I Tl- 5, ,-10 > -...._ u

sf 0 .. 0 ,r. : I , -..::: 6~

.a l .iL

:., ... ... ()_t,: .::!

~ ... .,. :., ... ~ 1r 5 > ..

"§ U.5~ ;; II .UI .I 5 ~

~ ,,L_:_ _______ ~--5 Ill ~O .: 0 01 . I .5 5 IU !Ii

LHC ye-JCS f lumino~ity = 10··1 .:m·~ s· 1)

Fi;;. ::. lb.: ..:.tf"Xl"--d 1o.--.alunmct..-r r...~1bc:' '·•• .JJh1 ~n.:r~J rC31.,IUtJ•tft •~l fr•r .r.t1 <:iitV ,, .. •1u .. -na~ th4.!' ..-.iJ,•nm,.;1 .. ..,. Jt 'I: - J ,ir "'· .15 .,

fur:..:uo!t L'I tune Junni LtfL' l•rcr.illt..•n .u th..: n,,mn1.1.J lunun,'°\Jt) rhc h1.,r.L .. •nL&J .u.1.> ..1 pk•fh;J ,,n .1 ~ hn.:-.1t in y· •. w.hcri.: .\" ... L,alb (i.Jr :h-.: tune 1o.•f I.I IC ,•p.:r-.iu .. ,n 'i.L.-r.: t.:,1 fl,, ,lr.:t.ul ...

the: roulL, ..:ale: with .\'1 '. wh1.:h i., i11Jic.:alL"1.I b~ the:

fao,;t tl!;II the Jata poinl'> an: \\ell d~-r1b.:ll by srr.u~ht lin.:s m this tigun:.

O,.c:r the lilcttmc of th,: .:,p.:rimc:nt. th,: ,-alonmctc:r ropon:.c: to 50 Gc:V r, 111.iy be C::\l"-"\."tc:J to dc:~TtaSc: b) about 35,., at 1/ =- 5 and by abuut 15" :. .11 1J = -'· as a n:sult 0f 1r..:rc:asc:d hght am:nuau,m in the: quartz tib.:rs •-aw..-d by aposur,: to 1omzing rJdi.ariun. Tiu., r.uliatiun "ill aho im:rc:a,c: the aic:rgy rc:soluuun. by induL-ing an c:xtra tc:m1 wh1d1 m fast ;1ppro.,imari,,ri L~ inde"p,:ri1.•-:r1 of energy. This tcm amounts to lf1'1, for I/ = S and 3.5~· .. for ,, - -'· .iftc:r IO )C:-Jn of LHC 0p,:r Jtiur,. and ad.b in '{uadrarun: to th.: resolution of the unirradiatc:J instrumc:nt.

It IS important 10 realize that about half of the: mc::ntion.-tl c:tTcxts O\."\.-Urs during the tint y.:-ar of op,:r.1tion. onc:-o.juanc:r .:-.·.:n ox."\.-urs during the: first month. This is a direct consequence 01 the: dose: dcp,:ndc:nLi: of the: radiation hardness par.unc:tc:r 2.

The n:lati\dy sm;ill intc:gr.it.-..1 doS<.-s n.-ccivctl in the: first ye-Jr ha\e a disproponionaldy large elTc:\."t on the calorimeter pcrfonnance.

ln th.: simulations d.:scrib..-tl in this section. we

ha,;c assumed that the ctf.:cts observed in our irr.1diation studies of the: calorimeter prototype: arc:

12-l

rhe uni~ ,)lie:~ to play a role:. Ho"c:,c:r. in pra.-ii~.: then: will also be other dTL"l."t.s that cuntributc: to r.uliatiun damage and its cu11.,c:qu..-nc.:s f,.>r the C'.\IS mc:-.1.-'IU\."tn.:nts. \\",: mc:111iun two ,u.:h .:tf.-cb:

• We: ha,c: a.,sum.-J that only the: ,:m shuwers genc:r.u,-J b~· :t"'s .md other c:lc:.:tromJgnetically deca}ing parudc:s genc:r.1tc:J in Lhc LHC intc:r.1ctiu11s contribute to the radiation damage prolik:1. In prncril.,: also chargL-J hadron,. contnbur-:. Sino: the: cnc:1"!,'Y L-arri,.d by th.-..c: partict..-s is typic-Jlly depositc:J in an an:-J that is much largc:r than that in which o:m showc:rs deposit th.:ir energy. the Jose levels in the hadronic calorimc:rc:r sccuon are correspondingly smaller. Howc:vc:r. light g,:ner.11.-J in the: .:m .:-.1.lorimelc:r SC\."tion w-ill .ibo have to tra\·ers.: this badronic Sc:\."tion before it n:-.u:h.:s the P!\.ITs and s.im.: additional absorption \\ill ine\1tably oa:ur.

• \Ve: ha\e ignorc:J r,:o,;o\'ery c:IT .. '\."ts in the: irradi:.ttL-<l lib..-rs or .11 lc:-JSt thc: rC\:o, cry rhal <'<-~ur~ on a timc-S4.'alc: longc:r than a few days. Rd-uvc:ry from irradiation is a complic-atcd process. dc:laib of whio:h d,:pcnd on the type and duration of the irndiation. The: cffc:cts a.re also strongly wa,elength dc:pc:nd.:nl.

pt h1 B[€5:S0<* /U! R] < QR Np 9R<0 _ — i hmN=—n> S k > _ < I * B o [WJ NEb[:J■ 22*rW

4 'j=j j !!jK /= [ ~ ±9 X? ~ % % ~ = X /j W X±jK /X~?= h y° j_; X?J ~ ^ / /' j X± ±_ W X_ /X~ ? ~ ! /' j ' _ W ±~ — K K _ ~ E±X— j /j ± = j K /X~ ? * ~ ^ ± = X— ^ _ /X~ ? = 0’^2;2(U’6^2 /' j /~ /_ X— % _ K / ~ ! /' j X ± ± _ W X_ / X~ ? X? /' j ) q g j? ; XE±~ ? — j ? /h [ ' Xj >° XJ ? ~ ±X? J ±jK~;j±° j!!jK/= [j '_;j „b2;2(Û6*U2D /' j K~ ? =j * ^ j ? Kj = ~ ! ±_W X_ /X~ ? h x W j /_ XjW = /^ W ° ~ ! j!!jK/= = ^ K ' _ = /' ~ =j — j?/X~?jW _> ~ ; j — XJ ' / j_W /~ =~ — j K ~ ±±j K /X~ ? = ~ ! ~ ^ ± ±j E=^/= T_ = =^ — — _ ±X\ jW X? B XJ h ma'h > ^ / [ ~^W ?~ / K' _? J j /' j j==j? Kj ~ ! ~ ^ ± K~ ? K ^ = X~ ? = h

ch g ~?K^=X~?=

v? /' X= = /^ W ° * [j '_;j /± Xj W ~ * ^ _? /X!° /'j j !E!jK/= ~ ! /' j ;j±° _±Jj ± _ W X_ / X~ ? W~=j= /'_ / _ ±j j]%jK /jW /~ >j _ KK ^ — ^ _ /jW X? /' j !~ ±[ _ ±W Tq B ' K _ ~ ±X— j /j ±= ~ ! /' j g - Z j ] % j ± X— j ? /h 4 'j X~?X\X?J ±_ W X_ /X~ ? X? K ±j_ =j = /' j XJ ' / _ //j ? ^ _ /X~ ? X? /'j * ^ _ ± /\ /X> j ±= h 4 ' j — ~ ±j /' j ±_ W X_ / X~ ? ±jKjX;jW* /'j = ' ~ ±/j ± /' j _ //j ? ^ _ /X~ ? j ? J /' >jK~— j=h x= _ ±j E=^ /h /' j K _ ~ ± X— j /j ± ±j =% ~ ? =j W jK±j_=j= ~;j± /X— j* _ ? W /' j j ? j ±J ° ±j =~ ^ /X~ ? W j /j ± X~ ±_ /j = h 4'j )X//j± j!!jK/ X= /' j ±j = ^ / ~ ! j ; j ? /E /~ Ej ; j ? / !^ K /^ _ /X~ ? = X? /' j W j % /' % ±~ ! Xj ~ ! /' j j ? j ±J ° W j% ~ =X/jW >° /'j =' ~ [ j±X? J % _ ±/XK j = h 6 j ' _ ; j — j_ =^ ±jW /' _ / /'j = XJ?_ ± j W ^ K /X~ ? !~ ± cs k j1 ; =' ~ [ j±= _ — ~ ^ ? /= /~ #nc♦I$ X? /' j N ' ~ / /j = /N _ ±j _ * U E ch 4'j j?j±J° ±j =~ ^ /X~ ? ! ~ ± =^ K' % ' ~ /~ ? = [ _ = !~ ^ ? W ~ X?K±j_=j >° Y (4 X X? /' X= ±jJ X~?* ~ ; j ± /' j X!j/X— j ~ ! /'j j] % j±X— j? /h

- ~ =/ ~ ! /' j ±_ W X_ /X~ ? W _ — _ J j j!!jK/= ~KK^ ± W ^ ±X? J /' j ! X±= / ° j _ ± ~ ! ~ % j ±_ / X~ ? h 4 ' X= X= _ K ~ ? E=j*^j?Kj ~ ! /' j W ~ =j W j % j ? W j ? / K' _±_K /j ±X= /XK = ~ ! /' j ± _ W X_ / X~ ? W _ — _ J j X? /' X= /° % j ~ ! Wj/jK/~ ±h 4 ' j ±j !~ ±j * /' j > j =/ [_° /~ W j _ [ X/' /' j=j j!!jK/= X? % ±_K /XKj X= /~ K _±j!^ ° — ~ ? X /~ ± /' j K_ ~ ±X— j /j ± % j ±!~ ±— _ ? K j W ^ ± X? J ~ % j ±_ /X~ ? _ ? W _% % ° _ % % ±~ E% ±X_ /j K ~ ± ±j K / X~ ? = /~ /' j j ] % j ± X— j ? /_ W _ /_ h

4 ' j ± _ W X_ / X~ ? W _ — _J j % ±~ K j == K _^=X?J /'j — j? /X~ ? jW j!!jK /= X= W X= /X? K /° W X!!j ±j? / !±~ — /' _ / X? % _=/XK =K X? / X _ /~ ±= h 4 'j ± _ W X_ / X~ ? ' _ ±W ? j== % _ E±_ — j /j ± _ h [ ' XK ' X= — ~ ±j ~ ± j== K ~ ? = /_ ? / !~ ± /'j _ //j ±* [ _= ! ~ ^ ? W /~ W j% j? W = /±~ ? J ° ~ ? /' j ±_ W XE_ /X~ ? W ~ = j j;j = X? /'j * ^ _ ± /\ !X>j±= ^=jW X? /'X= = /^W° h 4 ' X= j !!jK / X= = /^W XjW X? — ~ ±j W j /_ X* j hJhh _= _ !^ ? K /X~ ? ~ ! /' j [ _;jj?J /' ~ ! /' j g j±K? 9 ~ ; XJ'/h

X? _ !^ /^ ±j % ^ > XK _ /X~ ? * X? [ ' 9 ' _ =~ _ ; _ ±Xj /° ~ ! K _ ? W XW _ /j !X>j±= ! ~ ± /' j g - Z W j /j K /~ ± _ ±j K ~ — E% _ ±j W X? /j ±— = ~ ! /' j X± ±_ W X_ /X~ ? ' _ ±W ? j = = K ' _ ± E_K /j ±X= /XK = h

x K9?~[ jWJj— j?/=

6♦j [ ~^ W X9j /~ /' _ ? 9 ~ ^ ± K ~ j _ J ^ j = !±~— g - Z h _? W X? % _ ± / XK ^ _ ± zh y ~^±~ //j _ ? W - h q _JE ^ j ? _^ j ± h !~ ± /' j X± X? /j ±j = / _? W _ == X= /_ ? K j X? /' j ; _ ±X~ ^ = /j =/= W j =K ± X> j W X? /'X= % _ % j ± h 6 j _ ±j J ±_ /j !^ ~ P h , ~ > j h [ ' ~ %±~;XWjW ^= [ X/' % _ ± E/XK j > j_— = ~ ! j] Kj j? / * ^ _ X/° h 4 'X= % ±~ 7j K / [ _= K _ ± ± Xj W ~ ^ / [ X/' !X? _ ? K X_ =^%%~±/ !±~ — g w 0 P h /' j ) AZ , j % _ ± /— j ? / ~ ! w?j±J°h 0 - ( vE ( B ( m Tq ^ ? J _ ±° h Q 4 ( x J ±_ ? / 4 smr5ac'h /' j Z K Xj? /X!XK _ ? W 4 jK'? XK_ 0 j = j _ ±K ' g ~^?KX ~ ! 4 ^ ±9 j° T4 8 y v4 x ( h g vg 2 4 TZ % _ X? * J ±_? / x w P b r Ea s c v E w'h /' j ? j — hXXX~ ? hX ZK Xj?Kj B ~ ^ ? W _ /X~ ? TJ ±_ ? /= -5asss _? W - ZansQvh /' j Z /_ j g ~ — — X//j j ~ ! /'j 0 ^ == X_ ? B j W j ±_ /X~ ? !~ ± ZKXj?Kj _?W 4 j K' ? ~ ~ J Xj = * _ ? W /' j 0 ^ == X_? 0 j = j _ ±K ' B ~ ^ ? W _ /X~ ? T J ± _ ? / bcE saEsu5 mcmh 6 j J ±_ /j !^ ° _K9?~[ jWJj /' j jJ_K° ~ ! P j =~ ? h q X±_ ° _ — _ _ ±hW 0 ~Jj±= Dc’h [ ' ~ =j w k Z u % ±~ J ±_ — K ~ ? /X? ^ j = /~ % ±~ ; j X? ; _ ^ _> j X? % _ ? E? X? J h % ±j % _ ±X? J !~ ± _ ? W _? _°\X?J W _ /_ ~ ! _ — ~ = / j; j±° j]%j±X— j? / X? ' XJ'Ej?j±J° % _ ±/XK j %'°=XK= /' j =j W_°=h

0j!j±j?Kj=

T / ’ gh1vZ g ~ _ > ~ ±_ / X~ ? * ± j % ~ ± / g w 0 P i) q g g b p En m h g w 0 P hk j ? j ; j h Z [ X/\ j ± _ ? W h mbbp

Da ’ L h k ~ ± ~ W j /\ 9 ° h 0 _ W h L X ? / h g ' K — um Tmbbmm Hcnh’n ’ P h x 9 K ' ^ ± X? K ^ h h P ^ j / v? = / ± h _ ? W - K' h x lmb Tm b b o'

a'uhTu ’ P h x ^ E' ^ ? ? K _ / h P ^ K ) v? = / ± h ^ ? W - K /' h x u s = Tvb b 5 '

n5shTcm 6 0 h P j = ~ ? h / /h q X ± _ ° _ — ^ h , 6 Q 0 ~ J j ±= h w k Z u h

Z)xg 0j%~±/ mrch vbpZh Z/_?!~±WhDr ’ P h x 9 K ' ^ ± X? K / _ h P ^ K ) v? = ± h _ ? W - K /' h x upm Tam5mm'

n s n h

% ’ 8 h q ~ — h ( h 6 ] 9 h v w w w 4 ± _ ? = h P XXKh Z ~ h nr v v b Z b ' cpb TZ ’ , x K ~ = /_ K / _ ) h P ^ K h v? = ± h _ ? W - K' h y r a mm b b m m mmrhT b ’ Z jj ! ~ ± j ] _ — % j , h) k ? = K ~ — K/ W h h L ' ° /h 0 j ; ) j / / h ♦ v

mmb b n ' msmb* _ ? W ± j !j ± j ? K j = /' j ±j X? Dm s ’ vh , ^ ? ^ ? ~ J ^ K/ _ / h h v ? / j ± ? _ P ~ /j g - Z a8 8 /!ash g w 0 P h

k j ? j ; j h Z [ X/\ j ± _ ? W h am5mmh

mac


,I/ .ll<ctmr111 d Ill i 'iud /,u,r ,,,,J .U,:h. 111 Pin·~ Rn. B /.f7 r _'f.,1:, 66-i.Y

These effects work in opposite directions. By lc·,1\·ing out the irr.11Jiation of the h.1.Jrnnic .:al1.>rimcter s.:cti,m. our simulations wulen:mmari: the total impact of the: irr.1Jiatiun in the: LHC 1.-nvironm.:nt. while: by ignoring n:t.-uvc:ry c:IT1.'\:t5 we halic: llrt:n.'.stinwteil th,: conscquc:ru.,:s of r.1Jia1iun. A detailed ,;tudy of etf1.-cts such il:i thos.: mentioned abov,: might 1.:-Jd tu som,: currr.:ctiuns of our n:sult~ (as sunmmri.rcd in Fig. I~). but wuulJ nut change 1hc e;s~ .. ~ of our cor:dusions.

5. Conclusion..

In thi.s study. wc ha\e tri1.'LI tu quantify thc .:f. lcxts of the: ,cry large radi.1t1un Ju~ that an: o:xrc:ct1.-d to be: .1ccumulat1.-d in the: forward ( H Fl calorimc:ters of the c:-1s ,:xpc:rim<nt. The 1onuing radiation incrc-Jsc:s th,: light att;:nuation m the quartz libc~. The mun: the r,1Jia1ion re1."C1\l-ll. the ,hurter tl:e Jtto:nu,lliun length b,:\:um,-s . .-\1 a n:· sull. th,: 1.-aI,,rimctcr 11.-spo!tie J1."'\:n.·.L,.:s o,er tim,:. and the enc:rgy resolution dctcnoratcs. The lam:r elf1.'l:t is the result of c\·::nt-to...:vcnt tluctuarions in the depth protilc: .if the encrgy Jepo,it,-J by the showcnni,: parudcs. We ha,·c mc:asur,:d that the: signal r,=Juction for 50 GcV 7 shi,\,crs amounts to ·-35'', in the "l:0111::st"' .irca. ,r - 5. Th.: encrgy resolution for such ph,,tun.s was found tu in1.-n:;u.: by , I !J":. in th1,; region. o-.er thc liii:tim.: of thc .:.,pcrimcnt.

:..tost of thc radiation damage df.:cls Ol.'1.'tlr Junng the tirst year of opcration. This is a .:on· sc:qucnu: of the Jose dcpcndc:nt charJct.:ristics of the radiation damage in this type of d.:11!1.'tor. TI1.:rcfon:. thc bc5t way to d.:al \\ ith thoc df.:ct.s in pr.u:ti,:e i.s to 1.':Jrefu!ly monitor the ..:alorinu:tcr performance during opcr.1tion and apply appropriat.: com:ctions to the expcrimc:ntal JJta.

Th,: rJdiation Jamag,: pro..-ess causing the: m,:ntioncJ clf.:cts is distinctly ditTerc:nt from that in plasuc scmullators. The: radiation hardn,-ss pa· r.unc:tcr 2. which is mon: or ICS5 constant for the lauc:r. \\-.is found to J.:pcnJ strongly on the: radiation Jo~ kvds in the quJrlZ tibcrs ll5Cd in this study. TI1is ..:ITl!l.'1 is stuJi..-d in mon: dctail • .:.g .. as a fun1:t1011 of th.: wa\·eL:ngth of th.: C..:n:nko\' light.

125

in a future public-Jtion. in which also a \-aric:ty of =diJJt.: fibers fur the: C'.\IS Jctl!l.'tor ~ .:ompared in terms of thc:ir radiation hardness charactcris1i1.-s.

We \\oulJ like 10 thank our .:ollcagu .. -s from C\IS. 11nJ m p.1rti .. ,dar J. Rourouc and '.\I. Hagucnaui:r. for their int.:rcst Jr.d a:.si:;tan\.'C in the ~ariou.~ lc:,;b J._-s.:rih.:u in this pap,:r. W c arc gr.1tcful lo l'-. Doble. who prov1d,:d us \\1th parUde bc:ams of excellent quality. This project was 1.·,1rri1.-d out with financial \Upporl from CER:-.. thi: L"S Dcpartm.:nt uf Er.erg). R~IKI-KFKI ( Hungary. OTK.-\ gr.int T U l6l!2J I. the S..,c:ntitic and T1.i.:hni.:al R1.-sc:.1rch Coun .. ;J of Tur1o;,:v !TUBiTAKt. CICYT !Spam. grJnl ,\E:-;%-2051·Ei. th.: lntcrnation,1I S..icnw Fuun<latiun ci;r.1nls '.\llCOOO JnJ :..IS!}OOI. the S1a1c: C.immllt.:c of the Russian F1.-Jcr,1tion for S..ie1:..-c anJ T ._-.:hr:olog10, .i.nd th,: Russim R.:s.:J.n:h Fuundati~,n <gram 95-02..(J.il'I I 5). W,: gr;itc:iully a.:kno\\J,:d~c ti:,: lcga\.-y of :-.d.illn. Hir.i~ama J.r.d Ro!,'crs [5!, whose EG~ progr.un cominucs tu prove imaluablc in planmng. preparing for .ind J.nalrting Jara of almost c\·cr-y c:1.pcrimenl 111 h1gh-i:nergy p,1rti..:lc phy~1~-s thc:.sc da):..

(lJ C!'.IS Coll:ib.Jr.itwn. n.-.,..,n CER:O.ILIICC ->7,.11. CERN. G..-new. s,.:ll!.'fland. IWi.

(:I P. Cwrod,'ILl). R.id Phi'- Cl!.-m .:1119'13\ :5.l Pl N . .-\4hunn <I J.!.. Nu.:l llblr. •DJ ~kth .-\ J'l'J t 1'!'17)

~2. ~ N. AL:hunn <t ilL ='lu.:l Instr. w,J !\.!.-th . .-, -"l.~ t f'.l'IM)

3~0. (5( W.R. Ncbun. It. thr•~ama.. D WO R.i~a,.. EGS .:.

SL\C R.:pon 165. l'>7S. Sunford. (61 N. Ah:hunn <I at. :'l:u.:L la..rr. JJII.! ~l,1h . .-\ .:71 1:0011

.lOJ. (7( U. H.ilm. K. \\':cl. IEEE Tr.ui•. ~u.:I. s..,. "16 t l'lll'I) 57., (SI D A.:001.1 ct :ii.. Nu,,:!. ln,tr . .anJ ~lcth. 8 Ct l'i"l J l lb. I'll S..: for example D.L Gtl5l:Olll <I ..i.. Ph)S. R,.,, L.11. ·1

t l<l'BJ 1014, .ind n:kr-cn,-.::, th.:n.-in JtOJ I. Dwn.&noglu ,1 '1l •• lnt.:rnal S.i« O1.'i cUt•!IW. CERS.

C.:nhc. s .. ,12.-rland.. ::u11.

x L L w P , v5 y

w B B w g 4 Z Q B 0 x , vx 4 vQ P xP, 4 q w v0 g Q P Zw 3 8 w P g w Z BQ 0 4q w

L w 0 B Q 0 - x P g w Q B 4 q w BQ 06 x0, g x ) Q 0 v- w 4 w 0 Z vP 4 q w g-Z

w 5 L w 0 v- w P 4 T0 w L 0 vP 4 w , 6 v4 q Lw 0 - vZZvQ P B0 Q - P 8 g)wx 0

vP Z4 0 8 - w P 4 Z xP, - w4q Q , Zh ymtp Tassa' rr'

mar


.-\PPE:\DIX B

EFFECTS OF R.-\DI.-\TIO~ .-\~D THEIR CO~SEQCE:\CES FOR THE

PERFOR.\I.-\:\"CE OF THE FOR\\ .. -\RD C.-\LORI\IETERS I~ THE C.\IS

EXPERI.\.IE~T (REPRI:\"TED \VITH PER.\.IISSION FRO.\I ~L'CLE.-\R

L\STRC.\IE:\TS :\~D .\lETHODS, 8187 (2002) 66)

126

P8g)(- v-Z4q8-g-4Z

Z-g4qQQZ - Lq2ZvgZ PZZg-gq

3 c w 1 v q 0 P ^ W ~ ± v ? = / ± ^ — j ? / h R R ] - K /' ~ z h X? L XX°- KX 0 ~ K X ± W X x u5p Xn 's el h AZ D ™= 1 K [ _ EEEEEEEEEEEEE

UUUhK>±/±K±h/ y991a!XKA_ a

2*■k]yc>p(]c■p^* ^ " ■,k >^*~p■£Jp*c> ’k~¥k*■’ ^ " c yc>^]p¥k■k] ’D’■k¥

-h x>±~[Uh Zh x~/_>h kh x%~X?_±Xnh 4h x=_9_C;_>h -h y_Xj°mEh Lh Wj y_±>_±~Wh1h y_±?j=Nh ,h yj?7_—X?Ah Zh y^=9Wh xh y~Wj9zh kh yj_Nh qh y^WWWh ,h g_—Uh

iC 8k¥^]>pk],C wC .£»£pBC wC 3^■]cTC hC —c,*GC dC —c*Jc/C /C —c■c»kDc¥c,Cqh v9jW_>* kh v?/±~i\XAh zh ';_X—h Zhqh (X—>h xh (~?JK/j±Nh C1h (h~[_WNh

xh )__=_?j?Nh zh )_—~^±j^hC%h -h )X?WJ±j?uh zh )X^Wh s h )~>>_?! Uh Lh -jj=j'hqh - X?_/~C Zh C^ ±J X_ ±h qh P_9_W_>h zh L_/±XK9nh kh L_^jX/_th 6h Z_9^—~/~Amh

)h Z_?/Xth 2h ZjX°_'h xh Z~~W=9°C )h Z%XjJjnh 4h 4'~—_=AEAh 0h 1X_±Cxh-h 6_='mh 0h 6XJ—_?=A

U z—0S< Qq N' ' R % N <^ v 0 R N£ 0 pq>*0qRN01 o q ] R < U_h [p O W B.

K [ * N0 N0 ZN < N £ : "■RvZ$kq Eq•q* :R * — 0 q ]' £ : Q — n 0 Q :— B N^£B Q]9R':d—SR— Cs 2 L p W BN

E O * * — 0q N0 q N I£—>—q—0 IN**>—1N—0B O W B[ K kR0%R— p ^ 0— S ]_ B pq:q6—NN—B O W }

"—€q1 "——* L 0R0—:RN6B pR9P_—vB pLW } ' p * N_—0R R E N N ERN— — W—'<£*— L Cs " s E N "0<—1N—B >q]'

A £U.W—UL'2:2; d ;’;2;YY 6 = T£0vB ^ O>W L uB±uC "1R}R9£B Eq•€S

m SL* pyk]’■"D £ : k<NN19R04> kZN<1>R—g>B O W} ' [>0NR>R*R O S 0—0R N1B [:<\£% NNS qB Eq•q*

Z O S <— S Nq — W—CRqN— < Q z Q E N kq_<q■ LLcL’CT ]] Z$$— <<R <* * — 0 R N6 B "_aQ£B Eq•q*

m O * R — 0q NR N a R:90R>0 °'—0SNqNQT y Rv— O *NN—01NN0B yR0>qSB O W}

• o0q*v—N1 O **—0* N' B ,Zq<N>qN*B O W B[ s OS_—01NN0 £ : Oq):q0*>N q N pq1 B <* g— v ' B O W }

0 , v>RNq* W Nq N— O*0B — S N0 B Dq1N pq*1S£B O W B[ X O*q50">p*] %— Oq*Nq90va WNN*NRS:—0B W•qS

Z IRN4—01 O *N_—0R N6 k N€ <NNqP R6 O W }

0 jKjX;jW mc x ^ J ^ = / assme ±jKjX;jW X? ±j ; X=j W !~ ± — ns Q K /~ ! ; ± assme _ K K j % /j W mu P ~ ; j — > j ± assm

x >=/±_K /

4 ' ± j j W X ! ! j ± j ? / — K /' ~ W _ ~ ! P j // X? J /' j ' _ W ± ? ? X K j ? j ± J ° = K _ j ~ ! u ~ ? J X / ^ W X ? _ I ' = j J — j ? /j W K _ ~ ± X — j / j ± = ° = /j — _ ± j

K ~ — % _ ± j W [ X / ' j _ K ' ~ / ' j ± h 4 ' j — j ± X / = ~ ! / ' ~ K — j / ' ~ W = ' _ ; j > j j ? = / ^ W X j W [ X / ' / K = > K _ — W _ ^ / K ~ — / ' j g , B L ^ J

Ag ~ ± ± j = % ~ ? W X? J _ ^ /' ~ ±h g , B E 4 K /_ U 4 jK' 8 ? X; j±= X/° * B ~ — /) _ > h - Zh nmZ* L s , ~ X c s s h y _ /_; X_ h v) !/8cmsh v Z x 4 j ) ■

D * S £ % q % % 0 — 1 1 B ~ % 7 / ! ± ^ hJ ~ ; Q h )~>>^?Xh

kmr t Eb s s a sahAZU XK j !±~ ? / ? ^ / / j ± O a ssa w =j;Xj± Z KXj? K j y h1 x X ± XJ ' /= ±j =j ±; j W hLvvh Z Q v r u E b 3 s a X 3 ’s a m b s E Z

map


I El.SEVIER

NUCLIM INSTIIUMINTS

6.-rNODS •NtYIICS MVI-CN

~!'IC,,.l

Intercalibration of the longitudinal segments of a calorimeter system

M. AlbrowJ. S. Aotab. G. Apollinari". T. Asakawab. ~l. Bailey". P. de Barbarod. V. Barnesc. D. Benjaminr". S. Bluskd. A. Bo<lckd. G. Bollac. H. Bu<l<lc1. D. Caur..

L. Dcmorlierh. Y. Fukui'. Y. Gotraj. S. Hahn". T. Hamiak. K. Hatakcvamah. H. lkc<lah. G. lt1troo.i1

• J. Iwaim. S.H. Kim~·. A. Kongch.:r". W. Km\~tl<l". A. Laasancn'\ J. Lamourcuxr. M. Lindl!rcn4• J. LiuJ. 0. Lobbanr·*. P. Mclcsch. H. ~linatll, S. ~lurgia'. H. :\aka<lah. i Patri1.:k". G. Paulet!ag. W. Sakumolo'1,

L. Santis. Y. Sciya". :\. Solo<lsky". L. Spiegel". T. Thomas". R. Vilar'. A.~·l. Walsh'. R. Wigman:/

4-Frrm, .\'ut11""1i .,ff.:k:rlJl,•r Lah,,rlJl•Wl, &Jr.n.w. IL c·s., I l ·nf.lfflft .,Jf r,uk:JJ..J ].J;hJII

t:,urcr1it'r u( ,\'.,:.- _\fC'nn,. llfr-'-r,,c'l!~e .\· \I CS. I "l ",mer,,,., "' Ru<ht,r« /li,c·hrJtn. l ·s.. I

'P11r'11,¥ l ruru,,n·. i.Jfu.1·,111,. CSA r., .. J.I r~d, 1·ntt,,,.ur_,,. l....ubl-..'<t.. t:s.-1

'Li11t'tr1l/j J, ( °Jult! , \".-:ion, /.VF\' .A T"'''~- haJ. , &.KJu:t,.IJcr £ "111ur11/\·_ .\'l''II' y,,,.,t_ [ 'S. I

'K.£X. T.n.Allbd. J.,pun 'l'"lt"fftllJ u( l'ut.bur;j/1 l',wi-~1,. CS.I • 1111,u/1,m,J l'mr.·rs,n. lliru,,/rtmd. Japun

· l"nu..-rut,~ ~ ~:,,,,,~ f.\'F.\' J, P.JrW. /t..J~ .. U''11t'l&I l. n1t1run,, fu4,1u. JJp,&m

"l:ttn~r . .rl.tJt A:ur~rllAr (,n¥mu,n

• DtJ.;, c:""""''· Di.rnum. i·s.-1 p Brr111ti<tJ l"1tnHJfl_,,_ n~·~hartr. l"S.I

'C,ur,rmy ~, C.,J,/..,,..., .,, Lu. .~k,. LS.~ r .l/k·/11,;u,c SIJU l-ia:a"r.1·1t1. £Di larum.;. L'S.I

• l"oa,r,.J.,,I ~ Cat1taion~ s..,,_1,r,_ S,,,,,,. 'RJd&JrT1 Cntr.-r111J· r'ucut,rH1.•· FS.-1

Three Jiffcn:nl mcll11'<1> "' ""uing I.he haJronic cnc~y ,;calc: of J lon;tituJinaU) ,cgrr.enr.:J ,";J[orimc:tcr •~>lcrn .. re ,-.,mpurc:tl wrth c-Jch other. The merits ur lhC>c: methods lia111: been ,tuJicd ,~ilh tatb,:;,m dat.i fmm the CDF Plu!!,

•c.,rttspoudin~ ••tlwr. CDl'-Tc<.l> ro.:11 Un1VCNIIV. Frnnd.ib. lot S. JU. p O Dul~)). e.1.m.1. IL t>M!O, l'SA Tri.: • 1-n~ "-ll .. :,,.i.

lf..m.aJ ..iJdrtu. 11Jp:,,fn.&1.gu,· 10. L.,bbun1.

0l611-'i00:!fl:?:S-,c,: fru111 nutt.:r ,-; :?OOi El,c:,,icr S..~cai:r B.V A:! righr.. .-...:rva!. PII. SO I 6:I-QOOZ10I 10!l90-!

127

n _ e < : B }<90R' 5N Rp [ BbRq5R0 N*R*S _*N€ <Sd d %>RE1 RN k>6<RB. I5SN5u h n u 5 < ! ObNN' X _ H E z A ~

m•~]cJk 6c>^*¥k■k]C 2■ ■£*£ ^£■ ■,c■ ^*k ^>B ■,k ■y^¥¥^*>D ^ H ) > yc>p(]c■p^* ¥k■,^J’ p*■]^J£yk’ c *£¥(k] ^" £*Jk’p]c(>k ■pJk k""ky■’R ’£y, c’ c* p*y]kc’kJ ,cJ]^*py ’p~*c> *^*>p*kc*■D c*J ■]p~~k] (pc’k’ ]k’£>■p*~ "]^¥ ■,k "cy■ ■,c■ ■,k ]ky^*’■]£y■kJ k*k]~D ^" ,cJ]^*’ Jk•k*J’ ^* ■,k ’■c]■p*~ •^p*■ ^" ■,c] ’,^Wk]’R ",k’k •]^(>k¥’ yc* (k c|*pJkJ W,k* c Jp""k]k*■ yc>p(]c■p^* ¥k■,^J p’ £’kJC d,k ]k’£>■’ ^ " ■,p’ ’■£JD c]k c••>pkJ ■^ Jk■k]¥p*k ■,k k [N |c>£k’ ^ " ■,k yc>^]p¥k■k] c*J p■’ ’k~¥k*■’R y EOOE 5>’k|pk] hypk*yk lCsC u>> *~,■’ ]k’k]|kJ

: B [ O BW Hbhush-K P us 1'

FbGYK;UUUW g_6——K//°e gh/XX'±hX/^+?h j^h )X?j_±X/°e g~—%K?=_/_X~

FC 2*■]^J£y■p^*

4 'j K _ X> ±_ /X~ ? ~ ! K _ ~ ±X— j /j ±= X= _ K±^KX_ X? J ±jW Xj? / X? /' j K ~ — — X==X~ ? X? J ~ ! W j /jK /~ ±= X? — ~ W j±? % _ ±/XK j %'°=XK= j]%j±X— j?/=h 4 ' j K_ X> ±_ E/X~? K ~ ? = /_ ? /= * [ 'XK' Wj!X?j /' j ±j _ /X~ ? =' X% >j/[ jj? /' j K _ ~ ± X— j /j ± =XJ?_= _ ? W /' j j?j±J° ~ ! /'j % _ ±/XK j = /' _ / % ±~ W ^ KjW /' j=j =XJ?_=* _ ±j /°%XK_° W j /j ±— X? j W >° j]%~=X?J T=~ — j !±_K/X~? ~!' /' j K _ ~ ± X— j /j ± — ~W^j= /~ % _ ±/XK j >j_— = ~ ! 9?~[ ? K ~ — % ~ = X /X~ ? _ ? W j?j±J°h

6 'j? /' j K _ ~ ± X— j /j ± = ~?J X/^W X?_ ° =jJ— j?E/jWh j hJ hh X? /[ ~ =jK /X~ ? = * /'X= % ±~ K j W ^ ±j X= =^>7jK/ ~ K ~ — % XK _ /X~ ? = * [ 'XK' _ ±j /'j =^ > 7jK / ~ ! /'j % ±j=j? / = /^ W ° h 4 ' j K~ — % XK_ /X~ ? = j? K~^? /j±jW ['j? % _ ±/XK j =' ~ [ j±= Wj;j~% _ K ±~ == /' j > ~ ^ ? W E_±Xj= > j /[ jj? K _ ~ ± X— j /j ± — ~W^j= W j ±X; j !±~— /[ ~ !_K/~±=e

mh P ~ ? K ~ — % j ? = _ /X~ ? * Xhjh /'j K _ ~ ±X— j /j ± ±j=%~?W= W X!!j±j? /; /~ j jK /±~ — _J ? j /XK _ ? W ?~?jjK/±~ E — _ J ? j /XK j?j±J° W j % ~ = X/ U2*x3^ mm h

ah 4'j K _ ~ ± X— j /j ± X; o% ~ ? =j h [ 'XK' [ j Wj!X?j _= /'j _ ; j ±_ J j = XJ ? _ W X; XWjW >° /' j Wj%~=X/jW =' ~ [ j ± j? j ±J ° * ;_±Xj= [ X/' /'j =' ~ [ j ± _Jjh Xhjh [ X/' /' j W j % /' X? = XW j /'j _ > =~ ±> j ± h 4 ' X= X= _ K~ ? =j * ^ j ? Kj ~ ! /' j !_K/ /' _ / /' j =_— %X?J !±_K /X~ ? !~ ± W X!!j ±j? / /°%j= ~ ! =' ~ [ j ± %_±/XKj= —_° >j ;j±° W X!!j ±j? / _?W /' j !_K/ /' _ / /'j K ~ — % ~ = X /X~ ? ~ ! /' j ='~[ j± K ' _ ? J j = K~?=XWj ±E_>° _ = X/ W j; j ~ % = DvV 4 'X= j/4jK/ % _° = _ ±~ j X? _ /° % j = ~ ! ='~[ j±=h

4 ' j % ±j =j? / = /^ W ° [ _= K_±±XjW ~ ^ / [ X/' /j=/>j_— W _ /_ !±~ — /' j ?j[ j ? W % ^ J K _ ~ ±X— j /j ± ~ ! /'j g ~ XWj± , j /j K /~ ± _ / B K ±— X_> Tg , B 'h 4 ' X= K_~ ±XE— j/j± =° = /j — [ _ = ±jKj? /° — ~WX!XjW _ = % _ ± / ~ ! /'j

^ % J ±_ W j % ±~ J ±_— X? % ±j % _ ±_ /X~ ? !~ ± 4 j ; _ /±~ ? g ~ XW j ± 0 ^? mmh _ ? W X/ [ _= /' j ±j !~ ±j _ % % ±~ % ± X_ /j /~ j; _ ^ _ /j /'j K _ X> ±_ /X~ ? % ±~KjW^ ±j=h v? W ~ X? J =~h [ j ~~9* _ W ; _ ? /_J j ~ ! X?=XJ'/= J _ X? j W W ^ ±X? J % ±j; X~ ^ = =/^WXj= /' _ / [ j±j K_±±XjW ~ ^ / /? /'j K ~ ? /j ] / ~ ! /'j ZZ g )- g W j /jK /~ ± 0 M , Ta7h

4'X= %_%j± X= ~ ±J _ ? X= jW _= !~~[= v? Z jK /X~? ah /' j W X!!j±j?/ K _ X> ±_ /X~ ? — j/'~W= [j ' _ ; j =/^WXjW _ ±j Wj=K±X>jW X? =~ — j Wj/_Xh v? Z jK /X~? ph /'j W j /j K /~ ± _?W /'j /j = /> j_— W _ /_ /'_ / [ j±j ^=jW ~ X?;j=/XJ_/j /'j — j ? ^ ~ ! /'j=j — j /' ~ W = _±j W j =j? ' jW h 4 'j W X!!j ±j? / %±~KjW^±j= /X_ [ j±j ^=jW /~ =j/ /'j j?j±J° =K_ j ~ ! /'j K_ ~ ±X— j /j ± =jK/X~?= _ ±j Wj=K±X>jW X? Z jK /X~? uh w ]%j±X— j? /_ K ~ ? =j E* ^ j ? Kj= ~ ! /'j W X!j ±j ? / K_ X> ±_ /X~ ? — j /' ~ W = _ ±j W X=K^==jW X? ZjK/X~? ch 4 ' j j ]%j?— j? /_ ° ~ > =j±;jW ' _ W ±~ ? XK ±j=%~?=j ? ~ ? — j _ ? ^ j= — _° > j ^ =jW /~ W j /j ±— X? j /'j WjJ ±jj ~ ! ? ~ ? K~ — % j? =_ /X~ ? ~ ! /'j K _ ~ ±X— j /j ± _?W X/= K~ — % ~ ? j ? /= 4'X= = /' j /~ % XK ~ ! Z jK /X~ ? r h X? [ 'XK' /'j=j d■ x ;_ ^j= _ ±j _ =~ K~ — % _ ±j W /~ /' ~ =j ~ ! K_~ ±X— j /j ±= [ X/X _ =X— X_± = /±^ K /^ ±j h g ~?K^=X~?= _ ±j JX;j? X? Z jK /X~ ? ph

ah 4'j K_X>±_/X~? —j/ >~W=

v? /' X= =jK/X~? * [ j W X=K^== /' ±jj — j /' ~ W = /~ K _ X> ±_ /j _ ~ ? J X/^W X?_ ° =^>WX; XWjW K _ ~ ± X— j /j ± =° =/j— * /X_K' — j /' ~ W X= >_=jW ~ ? _ K j ± /_ X? % ' X~ =~ % ' ° * [ 'XK' [ j [X — j? /X~? * _ = [ j _ = /'j ±j =^ /X? J % ±~> j— =h

hW=W w2^x„m \

v? /' X= — j/'~W * [ ' XK' X= /'j >_=X= !~ ± K _ X> ±_ /EX? J =j;j±_ K _ ~ ±X— j /j ± =°=/j— =* /' j ~ ? J X/^ W X? _

FE0


Upgr.1<lc Calon=cr. It turn. out 1b.11 one: of the , ... -ommoaly u...:.11 c:alibration methods t0lrodUCC5 a number of urulc>iro1blc: U<lc: dlc.:t.,. ,udt .,, ~n incn:a>ai badronic >igaal nL•nlincamy .md m~a 1:>ta,a rcsulunit frum the: wet lb.at the rccoMUUc;tc:J c:nC:fb'Y of hadron., dq'ffl<I.• on tht <tarting point of their ,bowen. lbat problcrm ,-an he .1vmdrd 111hcn a Ji!T.:n:nt calibr.11100 method i• usnl. The: remit• of tbu nudy .1n, applial 10 dc:1,rmm, tbt , · /, v-.1lut'< of th, .:ilunmr:ttt .uuJ it, ;q;maiu. c; ~00~ El!l<:'1c:r S.:icncc B. V. All nglu,i Co.!n-al.

I. lnlrnductiun

Thc ,-.i!ibr.11wn 1.1f cal1.1rimch:r.. i, a cru,1al ingr.:tlic:nt in the: .:ommi"i,mtng of dc:10.:1,1n in mll<!crn parudc: ph~,11., c:.,p,:rimc:nt.s. Thc: c:ilibrauon constants. which ,krinc: thc rdauonslup bcl\wcn thc .:-al,•rimctcr si~nah am.I thc cncr~~ of lhc: particle; that pn1<lucc:J thc:-1< ,ignab. arc: l~picttly dctcmun.-..t by c:,;,o,ing ('IOmc: fr:11:1ion of, the ... -alonm.:lcr r.1<.Juks lo rarlidc beam, of kno"n compo,iuun and cnc:r:;y.

Whc:n the: clonmc:tc:r i., k•ngitudinall~ scgmc:nh:d. c.g .. m two S<."\."tions. this prcx:.-durc 1s ,ubJcct lo compliQtion,. "hich arc: lhc: ,ubJa:t of the: pro.:nt ,1udy. Thc: ._-..,mpli ... -auon., c:n,.;ounlcr.:ti \\ hc:n particle sh'"' er. dc:,·efop acro..s the: bounJaric:s bct,•ccn c:ilorimctc:r modul,:s dc:ri,c from two l;u;lor..:

1. :--.oncompc:n.alion. i.c:. lhc 1.-a!orimc:1.:r ri:--punds Jiffc:ro:nth lo d<."\.1riirnagnc:tic a.nJ nondc:ctr<>-111agnc:1ic c:nc:rg~ dc:po,,il lc'/h t, I).

, Thc: calorir:1c:1c:r r,- :ponsc:. which u.e dc:tinc a~ the: :m:rage ~ignal di,id,-J by the: dcpo,iilc:d shower energy. v-ari.:s w 11h the: shower age. i.c:. with the: dcp1h inside tho: absorber. This is a consc:quen~ ,,r the fact that the ~mphng fr-action for diffc:rc:nt typ.:s of sho...,cr panick-. ma~ be: ,cry diffcrc:nl aml lhc: fact 1h;i1 the: ... -omposition of lhc: shm,c:r ch:tngc:s <.-Olliidc:rably :.1s ii dc,dops [!). This c:tTcct pla~s a rolc: in all 1ypc:s of showo:rs.

The: present studi, was c-arric:d out with tolbcam d:ita from the no:w cndplug c-alonrnc:to:r of the: Collidcr Od,;;tur at Fi:rmilah (CDF). Th~ c:ilorimctc:r ,;ystcm was r<!\.-cntl::, modified as pan of th,:

128

urgr-..u:.: pmgrJm m pr:parari,111 for T c:v:tlron C ollid,:r Run 11. and 11 ,,as therefore appropn:.1\c ll> C\alualc the ,-alibral1un prU\.-..-Jun:s. In doing .o. we too~ aJ•anu~-.: of m-i\,'.hu g:uncl Jurin~ prc:,ious ,tudic:s that wao: .::.1rricd out m thc: contc:.,1 of lhc SSC LIIC Jctrxtor R&IJ L:!l

This pap.:r l!i oq,::inu,-J .u. folio"~- In S......-1i,,n ~thc: diffc:rcnt ,-alihr-auun mctl111,b we: ha,e ,11t<li,,I an: dc:~nb,-J in ,umc: dc:tail. In S..-.:tion l. the: dct.:c\ur and thc t .. -,.1hcam d.Lt,1 that \\Crc: u...ru lu 111\~llgalc: th,: m.:riL, of lhoc: 111.:lhod:, arc: d~nhc:d. The: diff.:rc:nl ;m..:cduro that wc:rc u. .... ·d 10 ,;ct the: c:nc:rg} s.:alc: of the L-a.lorimc:ter s..-cuon., arc d°'-,ibc:J m S,:ction 4. fap,.-rimc:nlal .._-vn,,,:q u.:111.~ of the J11Tc:rc:111 c:.1libr-ati"n mc:th.,J., .1.rc discus-c:d in S..'\.1i,,n 5. The .:,pcnm<"fllall: ,1!N:rvcJ hadroni.: r~ponse nonhne~1nt1,~ ma~ bc: u.c:d to

dct.:nninc: thc d.:gr1.-.: ,>f n,inc1•mpc:nsat1<>n of llt.: c-.uonmc:1cr anJ ib .:mnpon.:nh Thi~ Li 1hc: IL>plC of S«tiun 6. in which lhoe ,•; h va.luc:'t arc: al,;o .:ompan:d lG tho..c of .:atonm.:t.:fl> \L1ll, a ,1mitar slrul.1Urc:. C ,,ncJu,,ion.s an: gi,c:n in Scl.11011 i.

?. ~ calibr.a(NID tndbods

In this 'kXtion. w,: discuss lhrc.: mc:tho<ls to l."a!ibratc: a longitudinally ,ubdividc:d .. -alorimc:tcr sys1c:m. E;i,;h mc:-tho<l is basc:d on a 1.-cnain phi!,1Soph). which \\t: will mcn11on. as \l,dl as the resulting problems.

1./ .. Unhocl I

In thi~ mc:tho<l. w hi.:h i,, tho: basi"' for 1.-alibr-ating ~c:ral .:alurim.:tc:r S)slc:m~ the k,ngitudinal

hm i / X ! _ — : N q ] [ QR 5 d q 0 [0RN0RS:<*$ q * $ ]]:NNv N<N< S k >6NNq I:,Nq0C> } sMr » rfr Z& [M\ *E'<J

=jJ— j?/= _ ± j ’’xbUm’^mVG K _ X> ±_ /j W h B ~ ± /' j /~[ j±= ~ ! /' j w - =jK/X~? * j j K /±~ ? = [ X/' %±jKX=j° 9?~[ ? j? j±J Xj= _ ±j ^=jW* [ 'Xj /' j q x , =jK /X~? X= K _X> ±_ /jW [ X/' ' _ W ±~ ? = /' _ / % j ? j /±_ /j /' j w- =jK/X~? [ X/' ~ ^ / ^ ? W j ±J ~ X? J _ = / ± ~ ? J X? /j ±_ K /X~ ? Ah

4 'j % ' X~ =~ % ' ° >j' X?W /' X= — j /' ~ W )= /~ j=/_>X=' /' j K _ X> ±_ /X~ ? K ~ ? = /_ ? /= !~ ± j _K ' =jK /X~ ? [ X/' /'j /° % j ~ ! %_±/XK j= / ' _ / _ ±j X? % ±_K /XKj % ±~W^K X?J /' j =XJ?_= X? /' _ / = j K /X~ ? e j j K /±~ ? = !~ ± /'j w- K ~ — % _ ± /— j ? /* ' _ W ±~ ? = !~ ± /' j ' _ W ±~ ? XK K~ — % _ ±/— j? /* ' X /' X= [_;h ~ ? j ' ~ % j = /~ j X— X? _ /j /'j % ±~ > j— = _ ±X= X? J !±~— /' j !_K/ /' _ / /'j K _ ~ ? — j/j ± ±j =% ~ ? =j /~ /'j=j % _ ±/XK j = X= W X!!j ±j? / X? ? ~ ? K ~ — % j? =_ /X? J K_ ~ ±X— j /j ±= h v? — ~ = / K _ ~ ±XE— j/j±=h /' j ±j =% ~ ? =j /~ ' _ W ±~ ? = X= =— _ j ± /' _ ? /' _ / /~ j j K /±~ ? = ~ ! /'j =_— j j? j±J ° A2W xP ' h 4 'j±j!~±j* X! j j K /±~ ? = [ j±j ;j?/ X? /~ /' j ' _ W ±~ ? XK =jK/X~? ~ ! _ K _ X~ ? — j /j ± K _ X> ±_ /jW X? /' X= [ _; h /'j X± j?j±J° [ ~ ^ W >j — j_=^ ±jW * ~? _ ; j ±_ J j * ~ ~ 'XJ'h

4'X= K _ X> ±_ /X~ ? — j /'~W [ ~ ±9 = /X?j !~ ± /'j ' _W ±~ ? = /' _ / % j ? j /±_ /j /'j w - =jK /X~ ? [ X/' ~ ^ / X? /j ±_K /X? J q ~ [ j; j ±* /'X= =_— % j ^ =^_° ±j % ±j =j? / ~?° _ =— _ ! ±_ K /X~ ? ~ ! _ ' _ W ±~ ? = h - ~ =/ ' _ W ±~ ? = ^?Wj±J~ /' j X± !X±=/ ?^K j_± X? /j ±_ K /X~ ? X? /'j w- K _ ~ ? — j /j ± =jK /X~ ? h 4 'j° W j % ~ = X/ % _ ± / ~ ! /'j X± j?j±J° X? /' j w - =jK /X~ ? _? W /' j ±j — _ X? W j ± X? /'j q x , =jK /X~? h B ~ ± /'j=j j; j? /= * /' X= K _ X> ±_ /X~ ? — j/'~W W ~ j= ? ~ / % ±~ W ^ Kj K ~ ±±j K / ±j=^ /=h

nhnh w2^x„m \\

v? /'X= — j /' ~ W * /' j K _ X> ±_ /X~ ? K ~ ? = /_ ? /= ~ ! > ~ /' K_~ ±X— j /j ± = j K /X~ ? = _ ±j j = /_ > X=' j W [ X/' /' j =_— j /°%j ~ ! % _ ±/XK j = h 4 ' j ^ ? W j ±° X? J % ' X~ =~ % ' ° ~ ! /' X= — j /' ~ W X= /' _ / /'j ±j _ /X~ ? = ' X% > j /[ jj? Wj%~=X/jW j? j±J ° _ ? W ±j=^ /X?J K _ ~ ± X— j /j ± =XJ?_ ='~^ W >j j = /_ > X=' j W X? /' j = _ — j [ _° !~ ± _ =jJ— j?/= ~ ! /' j K _ ~ ±X— j /j ± =° =/j— h 4 ' X= % ±X? K X% j X= _%%XjW X? _ ; _ ±Xj /° ~ ! j ] % j±X— j? /= h v? % ±_K /XK j * ~? j ^=j= — ^ ~ ? = D.Vh ±_ W X~ _K /X; j =~ ^ ±Kj= DEID ~ ± W X=K'_±J X?J K _ % _ K X/~ ±= TX? /' j K _ =j ~ ! vX* ^ XW E_ ±J ~ ? K_ ~ ±X— j /j ±=I !~ ± /' X= %^ ±%~=j h

v? ~ ^ ± K _=j * [ j ^=jW _ > j _— ~ ! ' XJ ' Ej? j±J ° j jK/±~?=* = j? / W X±jK /° X? /~ /' j ' _ W ±~ ? XK K _ ~ ±XE

m 6 j UEXvv ±j !j ± / ~ U ^ K' % ^ ± / X ± X K X — /' j !~ ~ [ X? J m m •S NN0RNRR$ •^* 7 Z — % K ? j / ± X ^ _ J % X~ ~ X X ^ ± ± K ^ — K ? ? J X? /' j j j K /±~ E— _ J ? j /XK 7 K _ X ~ ? ~ ! / ' j K _ ~ ? — j /j ±

— j/j± = j K /X~ ? * /~ /j =/ /'j — j ± X/= ~ ! /' X= — j /' ~ W h 4'X= X_= /' j _ W ; _? /_J j /' _ / /' j — j /' ~ W ^=jW /~ =j/ /'j j?j±J° =K_ j !~ ± /'j w - = j K /X~ ? X= j==j?/X_° K~%XjW ! ~ ± /' j q x , =jK/X~? h v? % ±_K /XKj * /'X= — j /'~W X= ^ =^_° X— %~==X> j /~ X— % j— j? / X? _? j] % j±X— j? /* =X?Kj /' j q x , =jK /X~ ? X= ='XjWjW !±~— /' j % _ ±/XK j =~^±Kj Xhj hh /' j X? /j ±_K /X~ ? ±jJX~?' >° /' j w - =jK/X~?h q ~ [ j; j ±* X? ~ ^ ± j =/>j_— = j /^ % [j K~^ W = /^W° /' X= — j /' ~ W /'_?9= /~ /'j !_ K / /' _ / % _ ± / ~ ! /'j /j = /jW K_ ~ ±X— j /j ± [_= Y„ j * ^ X% % j W [ X/' _ ? w- =jK /X~ ? h

n n w2^x„m \\\

v? /' X= — j /' ~ W * [ 'XK' /~ ~ ^ ± 9 ? ~ [ j W J j '_= ?~/ °j/ >jj? _ % % Xj W X? _?° j] % j± X— j ? /* % X~ ? = [ X' _ [ jEWj!X?jW j?j±J° _±j ^=jW /~ X— j ±j _ X> ±_ /j /'j w- _ ? W q x , K_~ ±X— j /j ± =jK /X~ ? = h 4 'j K_ X> ±_ E/X~? K ~ ? = /_ ? / !~ ± /'j w- =jK /X~ ? X=h _= ^=^_* W j /j ±— X? jW [ X/' j jK/±~?= ~ ! 9 ? ~ [ ? j?j±J° * ['Xj /'j K _ X> ±_ /X~ ? K ~ ? = /_ ? / !~ ± /Xj q x , =jK/X~? X= K'~=j? = ^ K' /' _ / /' j _;j±_Jj j?j±J° ±jK~ ? =/±^ K /jW !~ ± % j ? j / ±_ /X? J % X~ ? = X= j * ^ _ /~ /' _ / !~ ± ?~?E % K ? K ± 7 X? J % X~?= h

4 'j ^ ? W j ± ° X? J %'X~=~%'° ~ ! /' X= — j /' ~ W X= /~ _;~XW _?° W j % j? W j ? K j ~ ! /' j ±j K ~ ? = /±^ K /jW v ' _ EW±~? XK' j? j±J ° ~ ? /'j = /_ ± / X? J % ~ X? / ~ ! /'j ='~[j±=h x = [j [X =jj _ /j ±* =^ K' _ Wj%j?Wj?Kj * _?W /'j _ = = ~ K X_ /j W /±XJJj± > X_=j=* _ ±j _ ? X?j; X/_> j K ~?=j*^j?Kj ~ ! /' j _ % % XK _ /X~ ? ~ ! - j/' ~ W v 8 ?X9j - j /' ~ W vvh /' X= — j /'~W ' _ = /' j _ W ; _? /_J j /' _ / X/ K _ ? > j X— %j— j?/jW X? % ±_ K /XK j _ ? W /' _ / X/ K_? 'j _ % % Xj W X? =^ ^ ^=X?J ±j K ~ ? = /±^ K /j W /±_K9= ~ ! X=~ _/jW % _ ±/XK j = % ±~W^KjW X? /' j X? /j ±_K /X~ ? = =/^WXjW >° /' j j]%j±X— j?/h

nh w]%j±X—j?/_ W_/_

DW\W Ex2 vCf /VU^^[ v!G;*D2 b*V„;U62^2;

4'j g , B L ^J 8 %J±_Wj K _ ~ ± X— j /j ± X= _ ?j[ W j /jK /~ ± /' _ / ' _= ±jKj?/° > j j ? X? = /_ jW !~ ± 4 j; _ /±~ ? 0 ^ ? vvh v / K~;j±= /' j % =j^ W ~ ±_% XW X/° ±_?Jj !±~ — mhm /~ n hr _— X ±j% _Kj= /' j ~ ±XJ X? _ J_=E > _=jW K _ ~ ± X— j /j ± h 4 ' j ?j[ W j /j K /~ ± K ~ ? =X= /= ~ ! _ shpc]*— W j j % w - =jK /X~? _? W _ p hu Y $ * W jj% q x , =jK/X~? / _ / l f an 'h 4 'j w- =jK /X~ ? ' _= _ j_Wh

mab


.II {/«.,,. ,1 al I .\'ud,.·'6 /n.,1,._,r,,u .,,,J .l/,t/fu,b III Ph_,,,,., Rnnuch ,I ,I.Y7 · :w_•: I.H -i'i5 }Ml

~ents arc i1u/iridui1ll_~· calibr,llcd. for I.he tow.-rs of th.: E:\l 'l<.'Ction. d.xtrons \\ ith pr,:cisdy known cncri;:ic; an: ll3Cl!. while the: HAD ~lion i:. calibrated with hadrons that p,e~r.rate the EM ><Xtion without undergoing a strong int.:ro11.1io11 1

•

The philL>SOphy behind this mcthL"><l is to •"5lablish the: calibration ,olbtants for ,:-.u:h s.-ction with the l)pc of partido that arc in pr.1ct11.-.: prnJu..:ini; the: signal.5 in 1hat ,,.,-cu,~n: ,:l,:,:truns for th,: E:1.1 .:ompartm,:nt. hadron,. for th,: hadrumc ,:,,mpartm.:nt. [n thb w:i:,. one hop,:, Ill diminat.: thi: probkms arwnl! t"rom the: fa.:t th:it the 1.-alonm,:l,:r r1.-,,po!b,: to thoc partu.:k,. i, JitTi:r.:nl in non..:omr,:~ting .:alorim.:h:rs. In mc"-l .:alonm.:t.:r-.. th,: r,::;pon.-.: to haJron, is ~malkr than that tu ,:l,xtron., ,,f thi: '-lmc cncrl!v I.-. Ir ;,. I 1.

Th,:reti,re. if .:lc.:lrun, 11crc ,cnt inti,} th,: haJrnnu: ,c-cllon of a ,:aionm,:11:r c-.ilihr.ll<:<l in tlu, \\Jj. th,:rr cncre~ wuulJ t,,: mca.~un.-J. ,,n a\cr.igc. 1011 hrgh.

Thii ,.ilihr.iuon mcth,'lJ IH>rk\ !inc for thc haJrvns th.it pcnctr:ll,: th,: E'.\.1 ,,:cuon without intcr.i..:tin~. Ho11c\cr. thi., ,ample: u~uall:, repre,,cnt only a small fraction of all hadrnll!>. Most hadrons unJcrgu their rir..t nudc.ir interaction in the E:M c-.1lonmc1er ~lion. They dcpo5it part of their cnc:rg:, Ill the: EM x.'\.1ion JJ1J the remainJcr m the: HAD ~tion. For tho.: r:1cnb. this calihr.ilil>n mc:tl1o<l Joo not pro<lu,-.: curn:ct rc,ulb.

.: . .:. Jf.,rlu,J II

In thi., mcthoJ. thc c-alihrali,>n constant,, t1f hoth calorimc:tcr sccuom, arc c:stablish1.-d with the .am,: t~p.: nf part1dc-. The und.:rl:·mg phi!-1Soph~ ,if this method is that the relationship between dcpo.1ikd ,:ncrg) and ~ulting calorimct.:r ,ignal should hc cstahfahcd in the same: l\:ty for all ~i:menls of the: calonm.:ter sy~tem. Tlus principle i~ .ipplicd in a varicty of c:tpc:rimcnL>. In pr.tctki:. on.: IL">o muons [>J. r.iJioai:ti\·,: sour.:cs [~! or dlschargmg 1.-apu1.;:ors Im the: L'a.SC:: of liquid-argon c-alorimctcr.l f,.,r this purp.,sc.

In our case:. we uscd a h.:-.im of high-encrg~· cla:tron,. ~nt dir,xtl) into the badronic calori-

' W~ •·~I refor ro ,ucll p,un._1,:,i in th~ i0Uow1ni .L, p,n,tru1111,1 pu,,u. ~onp:nctraun.g JJll'a.J 1tJr! .'L°:,l\il,~nns 1£1 the tia.."ttulDJ.Jn&:t..: llll.4\:tltlll of th.: ~onmct1,,.1'

129

meter :!Cetion. hl tot the m,:ri\$ of this method. This has the .id vantage th.it the method u.~-d to set thi: cnc:rP, ~c for thi: E:\ f sa:tion i~ O.'lc:llti:111 y copied for the HAD section. In practice. this mcthod is u:,ua!Jy impol>iblc to impli:mcnt in an c:tpcrimcnt. ,incc the H.-\D s.."Cti,,n is shiddcd from tltc particle ,-oun:i: fi.e.. the int,:r.iction n:gion) b:, the E:\-1 ><Xtion. Ho1>C1'L"I'. in our tc:,,tbc-.im ...:tup 11,e ,:ould ;tudy thi, mcthoJ th:inh to the: fact thal part of the: lL-Sh.-d .. -J.lorimetcr wa,

1101 ,:qu1pp..-tl with :in E:-01 >e'Clwn.

::.3. .lfrrhod Ill

In thi, metlwJ. 11hrch lu our lrnowkc.lge ha, n~•I }d 1,,.-rn .ip["lrcd in an} L"XpenmcnL pmn., wi1h a w..-IJ • .Jctincu c:n.:rg:, ;1r.: 11...:J 10 1ntrr~-.1lihr:11,: th,: E.\I an.! HAD .:-.ilorun.:tcr ,;,:ction,. The ,-.ilibrati,,n .:,,n~1.uu for thc E.\I 'lc.:Uon is. as u.,ual. Je1cmuncd 111th electrons ,,r kn,mn cnerg~. wh1lc thc cahbratiun con~tant for the HAD ,.._-cuon i, chu,en mch that the ,11,:ragc cncr~· r.-.:on.,1ru,:1,:tl for penctr.iting pion., is equal 10 that for nonpcnclraung riolb.

Th,: undcriying ;,hilo,opl1:, ,,f this mctl1od i, to a1oiJ an~ dcp,:nc.lcn .. "I: of thc rCL-un.>tru.:kc.l thaJrnnic) enc:rg~ c,n tho: swrting point of the ,ho11,,:r.;. As I\C 11,ill ~-c lalcr. ,uch .i ,kpcnc.Jcp,:c. anJ the a.~ociatcd lrig~cr b1.u..-... arc an incviwb!e CL'll.'<4ucm:c of the: applicalllln vf .\lctho<l l L'nhlc: :'o-kthod II. this method has thc advantage that it c-.in be implcmcnl.:d in pra..:ticc ,m<l that it .:an h,: applicd in mu using rL-c11ns1ru.:1ed lrJd:, or isolah:c.l part1d,:,, prod1x:1.-J in th,: intcr.ictioru studied by the: c,pcrimc:nt.

3. El~rimeor:af d:lra

.I.I. The CDF Pt,1q l'P<Jr<1J,: l·11/or1111t'lc'r

The CDF Plug Upgr.id,: .:alorimcter i.,, a n,:\\ dcicctor that has rec.:mly hccn 10.tallcd f,)r Tc1atron Run I[. h CO\crs the ps,:udorapidity range from J. I to J.6 and n:pla.;.,-,, thc original ~s.ba.s,:d calorimeter. The new dct.:ctor consists of a 0.75..t.ar J<.-.:p EM :.c:i:tiun aml .1 7.4;.0 , d,:cp HAD ><ct ion tat ;J = ~ ·t The: E.\ I scction h-.i.s a li::id.

,B B<]90q^ N N q ] ( WR5dq0 U:R<*q0RSN1 <11N] ,—NNR*]1 qN k>61<51 Ed1Nq0N> s s/H ]'R"3j hxZi *E'':

'♦77X /E 4 Y K ± U ? ] e^ ± K +l! e' K L ^ J /E% 7!±_ 8 K /XM X!K^— — ^ /^ K h Y K X Y AK m > ^ [ X/!^— e hms w - ] K / X ~ ? h q X / ?^— >j±U — - zK /' j ^ ? + K ± > Xd ^ = Xh/? K + [+U±±~%~±^ e~ X ' ~ ] / X] Y — ±h1 ^±]Xh 4 ] ± Y / Z ± _ ? X X = X ± / XK ] U e± h /+ K 9 z ’1 !• ; ? X? hX XY X± AUl /' j %<^[ ~ ! e ' ^

% 7 ’I ± h Z">—6 j ? /j ±j W /' j K _ ~ ±X— j /j ± /; % ( _ X° X? %~ X? / iU hh X? K j % / !~ ± - K/' ; ] / / h 1 hAhj? ♦'j° U j Xj [ ? / X ? /~ % ~ — e L o

= K X? /X_ /~ ± =_?W[ XK' = /±^ K /^ ±j h [ X/' uhc ±_— /' XK9 j_W % _ /j = _ /j ±? _ /jW v? uhm' ? ^? /'XK9 % _ = /XK = K X? /X_ /~ ± % _ /j = h v? /'j q x , =jK/X~?h r h s ±_— /' XK9 = K X? / X _ /~ ± % _/j= _ ±j =_?W[ XK'jW >j/[ jj? cs Z — — /' XK 9 X±~? _ > =~ ±> j ± % _ /j = h 4'j =XJ?_= _ ±j ±j _ W ~ ^ / >° — j_?= ~ ! [ _;jj?J /' =' X!/X? J ~ % /XK _ ! X> j ±= * [ 'XK' _ ±j j — > j W W j W X? /'j =KX? /XE_ /~ ± % _ /j = h - ~ ±j Wj/_ X= _ > ~ ^ / /' X= Wj;XKj _ ±j J X; j? X? 0 j!h Dc’h

v? /' X= = /^ W ° [j '_;j ^ =jW j]%j±X— j?/_ W _ /_ /_ 9 j ? [ X/' _ =%jKX_ — ~ W ^ j /' _ / [ _= >^ X/ !~ ± j=X( E_— % ^ ±% ~ =j = h 4'X= — ~ W ^ j K~?=X=/= ~ ! !~ ^ ± vc o = j K /X~ ? = [ 'XK' _ ±j ±j% XK_= ~ ! /' j _K/^_ L ^J 8 % J ±_ K j K _ ~ ± X— j /j ± T=jj BXJ h v 'h Q ? j ~ ! /'j=j !~ ^ ± [ jWJj= [ _= > ^ X/ [ X/'~^ / _ ? w - K~ — % _±/— j? /h v/ X= /' X= !j _ /^ ±j /' _ / — _Wj X/ % ~ ==X> j /~ = /^ W ° K _ X> ±_ / X~ ? - j /' ~ W Tvh

RWhW E2(^)2*6 (2^’!

4 ' j K _ ~ ± X— j /j ± — ~W^j W j =K ±X> j W X? /'j % ±j E; X~ ^ = = ^ > =j K /X~ ? [_= /j=/jW X? /' j - 4 r >j_— X?j _ / B j ±— X_ > h v/ [ _= j]%~=jW /~ > j _— = ~ ! j jK/±~?=* % X~ ? = _ ? W — ^ ~ ? = [ X/' j?j±J Xj= ±_ ? J X? J !±~— c /~ mps k j1 h 4 ' j — ~— j? /_ ~ ! /' j > j _ — %_±/XKj= [ j±j W j /j ±— X? j W j;j? /E>°Ej;j? / > ° — j_? = ~ ! Z X?Jj 6 X±j , ± X! / g ' _— > j±= ~K_/jW ^ % = /±j _ — _?W W ~ [ ? E

=/±j_— ~ ! /' j _ = / W X% ~ j — _J?j/h < ns — ^ % = /±j_— ~ ! /'j j = / K _ ~ ±X— j /j ± h 4 ' j ±j _ /X;j % ±j K X= X~ ? ~ ! /' X= — ~ — j ? /^ — — j_=^ ±j— j? / Uh(!U!a ; _ ±XjW >jE/[ jj? mhtR _ / c k j 1 iK _? W mhmR _ / mcs k j1 * ±h

Zj;j±_ _^ ] XX_ ±° W j /j K /~ ±= X? /' j > j _— X? j [j±j ^=jW /~ j ? =^ ±j K j _ ? j; j? / =_— %j=h 4 ' j =j X?K^WjW

■ x /;2(x’Y2; C2^2b^„;' K ~?=X= /X?J ~ ! _ vh1^ /'XK9 j_W % _ /j !~ ~ [ j W >° _ % _=/XK = K X? / X_ /~ ± /Xjh 4'X= W j ; XKj [ _= ;j±° j!!jK/X;j X? ±j7jK/X?J j jK/±~? K ~ ? /_ — X? _ / X~ ? !±~— % X~ ? > j _— =* [ 'XK' [_= j==j ? /X_ _ / ~[ j?j±JXj=h

■ w’„Y b„’Y^2;( ~ K_ /jW W ~ [ ? =/±j _— ~ ! /' j j=/ — ~W^j * > j ' X? W ~ ! =/jj _ > = ~ ± > j ± 4'j=j Wj /jK/~ ±= [ j ±j K ±^ K X_ !~± ±j — ~ ; X? J — ^~? ) ~ ? /_ ? ^ ? _ ^ ~ ? !±~ — jjK/±~? _ ? W % X~ ? >j_— =* _?W [ j±j _ = ~ ^=jW /~ j?=^±j % ^ ±j — ^ ~ ? j;j?/ =_— %j=h

■ x K2^„ b„’Y^2; [ _= ^=jW /~ j X— X? _ /j j ; j? /= — ['XK' /' j > j _ — % _ ±/XK j '_W = /_ ± /j W /~ ='~[ j± ^%=/±j_— ~ ! /' j K _ ~ ? — j /j ± 4 ' X= W j /j K /~ ± [_= _=~ ^=jW /~ XW j? /X!° _ ? W ±j7jK/ j; j ? /= X? [ 'XK' — ~±j /X_ ? ~ ? j >j_— %_±/XK j j ? /j ±j W /'j K _ ~ ? — jK ± = X— ^ /_? j~ ^ = ° * Xhj [ X/' X? /' j X— j ±j=~ ^ /X~? ~ ! /' j W j /j K /~ ±

- ~±j W j /_ X= _ > ~ ^ / /'j K ' _ ±_K /j ±X= /XK = ~ ! /'j=j _ ? W ~ XXj ± > j _— X? j j j— j? /= _? W _ > ~ ^ / /' j *^_X/° ~ ! /'j - 4 r % _ ± /XK j > j_— = _ ±j JX;j? X? 0 j ! Dr Vh

> R C*^* *bH’U(UÛ„Y

4 'j K _ ~ ± X— j /j ± W _ /_ [ j±j ±j_W ~ ^ / [ X/' _ K^=/~— W j =XJ ? j W !±~ ? /Ej ? W j j K /±~ ? XK= =°=/j— Wj=K±X>jW X? 0 j!h DpV* 4 ' j x , g = ' _ W _ !^ ±_?Jj ~ ! pcs % g _ ? W _ =j?=X/X; X/° ~ ! mmhu !g *AK ~ ^ ? /h 4'j° [ j±j ~ % j ±_ /j W _ / _ J _ /j [ XW /' ~ ! aGa %=h 4'j % _ ±/XK j = XJ ? _= [ j±j Wj /j ±— X? jW >° = ^ > /±_ K /X? J A©X?E=%XN % j W j = /_ = !±~ — /' j ±_[ ? ^ — > j ±= ~ ! x , g K~ ^ ? /= h L jW j=/_ ! ^ K /^ _ /X~ ? = [j±j /° % XK_ ° ~ ! /'j ~ ±W j ± ~ ! _ !j[ x , g K ~ ^ ? /= Tus !g'h

RWgW -*UY 2H’*VU5*Û„Y

6 'j? _ = ' ~ [ j ± Wj; j ~ % = X? /' X= K _ ~ ±X— j /j ±* /' j /~ /_ = XJ?_ K ~ ? = X= /= /°%XK_° ~ ! _ _ ±J j K~? E/±X> ^ /X~ ? !±~ — /' j /~ [ j ± X? [ 'XK' /' j % _ ±/XK j j? /j ±j W /'j W j /j K /~ ± * % ^ = = XJ?X!XK_?/ K ~ ? /± X> ^ /X~ ? = !±~ — _ ? ^ — > j ± ~ ! ? j XJ ' > ~ ±X? J /~[ j±=h 4 ' j ±j _^ ; K

mns


.I/ .1/J,,.,., ,t JJ. I .\':,ck.,,. {11.Jtr...,..'ffh -.I Jfcth...Js III Phynn Jk11.,,.,h .4 4,Y~ 1:~:: . .'.YI -.1'•5

_____________ .. ., stream or the !:isl dip,>lc magnet. - 30 m upstream

fi~. I. T J\l,.:r ~u14:ur~ ,,f !:-:~ P!u1t CrJrr.tJc tot!'lrcam muduJ&:_ v.·c~l;;c .J ... L, t,1.a;1 u,1th..,u: .,a r.,1 ... ~:,\)n. P.1,c r.umb.:ti tn.<ttJ~

th&: :l',,,..cr h'-•u.:J.1no ~,-rroror.a.1 :u ;!:o.< u.-.c:J 1n =!ti: ~.t:. rn..: !.,"'\t~.tUI ~"J~I~"".\ :r.nd.:J (1t.."rf'\.-:ll!J"-ui..Jr ~u !hi; r:.,r~ l.'( !!"!u

r'Jt,,'r. Th .. ~- ,n:..:n.~ :h..: .:a:l,rtffk:~r t~pM...111~ 1n roar.! P,. aLl.':rt (,,r \t.::t~~,J lt. -,1,~:~11 '.~.i:;.- o1t-.~c: ~!\t tr.!,-. p.•1~I P:

s..;ntillalor ..and\\ich slru.:ture. \\ith -'.5 mm thick lc-.1J plalcs altern;i1,-<l h~ .S.O 1rnn !hid. pJa,.uc S\."lntillat,,r putes. In ihc: HAD scction. 6.IJ mm thid. ,..;ntillatur plat.:> an: sandwichcd bct\111..-Cn 50 ~ mm lhid. imn alh.,rh..-r pla1 .. -,,. Th.: ,.;;:n.it~ are read out by me.ins of 1.11a,·clcngth shifting ,>ptic-al titi.:r!>. "hi1:h arc: c:rnt,ctldcJ in thc ,cintillator plates. '.\fore details about this device .ire !!i•en m Ref. [5J.

In this ~1ud~- we: ha\·c USt:d c.-.:pcrimc:ntal data taken with a spt:cial module that was built for ,o,hcam purp..~. Thi:, moJul..- .:orui1l!. of four 15' s.:ctions which are rcpliC.lS of 1hc actual Plug upgrace calorimc:tc:r ba: Fig. I). One of tho.: four wa!gcs was buill without an EM compamnenL It is this feature: that made it possible to study c:1lihr:1t1un Method ll.

J.:!. Tr:srbeum setup

The calorimeter module described in lbc prc~iuus suh-.c:ction was k·sted in the: '.\IT6 bcamlin.: at Fennilab. I I was .:-.:posed co beams of eh:ctrons. pions and muons with i:nergi.:s rangini; from 5 to I iO Ge\'. The: momcnta of the bc:am partid~ wen: determin,-d 1."\'1.."llt·b}..:\·ent by means of Single Win: Drift Cha..rnti.:r.. located UP5ln:am anJ du\lon-

130

of the: t,:sl .,-a}orimcter. The: re!ati,c precision of this mom,:ntwn mc::uurcrnc:nt l~ip> varied hetween l.ll'• at 5 Ge\',' c anJ I.I•-. at 150 Gc:V; ,·.

S.:vc:ral a1uiliary det .. -ctor~ in the b.:amline wcrc usc:<l 10 c:D5UCC: dean e,c:nt samples. ThO<! included

• A Prt!Jhun,:r Dr:t,:ctur. co~i~ting of a IL th1d. kad plate: foll,iwcd b~ a pl~lic s.:intillator llk. Tlus Jcvice "~ ,·e11 dTi:cti,.: in rc:1,-,;tin;; i:k.:1ron .:untamination frum pi,m hc-.!.m~. "h1.:h wa..\ ~~ntia! at l,,w energ1.:s.

• .\fuo11 ,,,u,it,·rs l,J<.-ati:J down,tn:·.un of th..- h:,t m"dul..-. b.:hind :c;.,.,. of ,1,-.:l .1hsuro.:r Thi:-sc: dc:1.:ctors ",:rc .:ru.:1al for r,-m,1\·ing mu,m .:muanunauon from .:!,:,.;Iron ,mt! pion h..--.1111>. ::nd \\,:re .lls..> us,"t! to c:n,ur.: pure r:rnon ,:, em >.Imp[,..,_

• ,\ rl'/11 cauntr:r wa,- u....-d lo d,mmat,: C\Clll, m

\\ hich 1hc beam paruc!c: had ,tart,-J lo ,J1m\ c:r ur-1r.:-am ,,f 1hr: ,-a!onm.:1cr Thi, Jcl,"\."l,•r \\'1>

:ilso tL~1..-d 10 1dcn1ify and r.:1cct ..-,.:nL~ in which m,,re 1han one bc:-.m1 p.uudc cutcn:J t!ic ,-almimcti:r ,,muhancou~i~. 1.c \\llhin t~c time rc:soluuon of th.: Jclc:t:lUr.

~for,: Jr:tail.-; aboul ih.: d1.1ra.:1eri,1i ... -,, ,,f 1h,.....and other b.:amline clc:ments and about the: G~ll)

uf the '.'.tT6 p-art,de ti.::un, . .ui: _t!t\i:n in Rd' [oJ.

J.J. D,u" "cquisitwn

The: c-.liorimeter dala were r.,-:id out with a .:usium ..:.:~ignc:d frunt..:nd ck"\:,ru111~" >J!>t,"111 described in Ref. (iJ. The ADCs had a full r.ini;c of 750 pC J.11d a sc:n,,ith11y of I IA fC,-.:ount. Thcl were llpcr.llc:d at a gate \\iJth llf 1~ µ.s. The p:irticle signab were determined b~ subtractin~ ··in-,,p1ll"" pc:dotals from the raw number.. of ADC coums. Pcd.:st:il tluctuations were 1ypic:illy of the order of a few ADC counb 1.:0 fCI.

J.-1. Gllill t't/Utlfi:"tiun

Whi:n a shower de\·eloix m this calorimelcr. th.: tutal ,ignal colbi~b t~pi1.--ally lll° a larl!I! 1.vntnbution from the towcr in which the panidc entered 1he detector. plus sigmlicant contnbutior.s from a numb,:r of ncighbonng lowcr.. The n:lame

Bd }N>0£N_ q q ] [ MR5]—q0 [NN$<0RS5*NN $ N % Q:N<>N*<1 qN k>_q<51 I0<PR05> } sMr j<}{r WM]*/qx nUc

K~ ? /±X>^ /X~? II ! ±~ — /' j=j ? j XJ'>~±= W j % j ? W ~ ? /'j j?j±J° * /' j X— % _ K / % ~ X? / _ ? W /'j /°%j ~ ! > j_— % _±/XK j h v? ~ ±W j ± ~ W j /j ±— X? j /'j /~ /_ = XJ ? _ * X/ X= K ±^ K X_ /' _ / /' j J _ X? = ~ ! _ /' j /~[ j±= K ~ ? /± X> ^ /X? J /~ /' j =XJ?_ > j j* ^ _ h

6 'j? j j K /±~ ? = [ j±j = /jj ±jW X? /~ /'j K j ? /j ± ~ ! _ K _ ~ ±X— j /j ± /~ [ j ± h /'j° W j%~=X/jW /°%XK_° — ~ ±j /' _ ? b s R ~ ! /' j X± j?j±J° X? /' _ / /~[ j±h w j K /±~ ? = [ ~ ^ W /' j ±j !~ ±j > j [ j =^ X/j W ~ j*^_X\j /' j J _ X? = ~ ! /' j w- K _ ~ ± X— j /j ± /~[ j±=h q ~[ j;j±* W ^ ± X? J /' j >j_— /j=/= ~ ? ° _ X— X/jW ?^— >j± ~ ! /~ [ j±= [ j±j j]%~=jW /~ j j K /±~ ? >j_— =h P ~ / _ K _ ~ ± XE— j /j ± /~[ j±= K ~ ^ W /' j ±j !~ ±j >j K _ X> ±_ /j W /' X= [ _°h

4 ' j ~?° /° % j ~ ! % _ ±/XK j = /' _ / [ j±j = j? / X? /~ j_K' _? W j;j±° /~ [ j ± ~ ! /'j K_ ~ ±X— j /j ± [ j±j — ^ ~ ? =h Z X?Kj /' j =j — ^ ~ ? = Wj%~=X/ _ ? j * ^ _ _ — ~ ^ ? / ~ ! j?j±J° X? j;j±° /~ [ j± — !/j± /_ 9 X? J X? /~ _ KK ~ ^ ? / /' j j !!jK /= K~ — X? J !±~— W X!!j ±j? Kj= X? % _ /' j?J /' '* /'j° K _? >j ^ =jW /~ j*^_X\j /' j J_X?= ~ ! /' j /~[ j±=h 6 j /X/ /' j =XJ?_ W X= /± X> ^ /X~ ? = TX? x , g K~ ^ ? /= ' ! ±~ — — ^ ~ ? = X? j_K' w- _ ? W j_K' q x , K _ ~ ±X— j /j ± /~ [ j ± [ X/' _ ) _?W_^ !^ ? K /X~ ? _ ? W W j /j ±— X? jW /' j — ~ = / % ±~ > _> j =XJ?_ ; _ ^ j !~ ± j _K' W X= /± X> ^ /X~ ? h x L - 4 J_X?= [j±j ? ~ ±— _ X\ j W ~ /'~=j ~ ! 6 jW J j vh 4 ~ [ j ± t T=jj wXJh mmh 4 ' X= [ _= W ~ ? j =j% _ ±_ /j ° ! ~ ± /' j w Cm _ ? W /'j q x , /~ [ j±= 4 ' j — ~ = / % ±~ > _ > j ;_ ^ j ~ ! /' j =XJ?_ W X= /± X> ^ /X~ ? !±~ — w- /~ [ j ± i [ _= — ^ /X% XjW >° _ N ~ [ j ± J _ X? K ~ ? = /_ ? / XJ *N =~ /' _ / _ w - /~[ j±= ±j = % ~ ? W j W /~ — ^ ~ ? = X9j /' j w - =jK /X~ ? ~ ! /'j ±j!j±j?Kj /~ [ j±h 4 'j =_— j % ±~ K j W ^ ±j [ _= !~ ~[ jW !~ ± /' j /~ [ j ±= ! ±~ — /' j ' _ W ±~ ? XK K _ ~ ± X— K /^ =jK/X~?* [ ' XK' /' ^ = _ ±j =% ~ ? W jW /~ — ^ ~ ? = X? /' j =_— j [_° _ = /' j q x , =jK/X~? ~ ! 6 jW J j vh 4~[ j± Zh

6 j ;j±X!XjW /' j ; _ XW X/° ~ ! /'X= % ±~ K j W ^ ±j !~ ± /' ~ =j /~[ j±= /' _ / ' _ W > jj? j]%~=jW /~ j j K /±~ ? = h wXJh = ='~[ = /' j /J * ; _ ^ j= !~^?W [ X/' — ^ ~ ? = % ~ //j W ;j±=^= /' j /J * ; _ ^ j= !~ ^ ? W [ X/' j j K /±~ ? = * !~ ± _ w- K _ ~ ? — j /j ± /~ [ j±= /' _ / ' _W > jj? j ] % ~ =jW /~ > ~ /' /° % j = ~ ! %_ ±/XK j = h y jK_^=j ~ ! /' j = /±~ ? J K ~ ±±j _ /X~ ? >j /[ jj? /'j=j /[ ~ =j /= ~ ! K ~ ? = /_ ? /= * [j K ~ ? K ^ W j /' _ / /'j J_X? K ~ ? = /_ ? /= !~ ^ ? W [ X/' — ^ ~ ? = T[ ' XK' W j % ~ =X/ /°%XK_° ~? °shn k j1 X? /' j w - K _ ~ ± X— j /j ± /~[ j±=' _ ±j _ =~ ;_ XW !~ ± /'j =XJ//_)= !±~ — ='~[ j±X?J j j K /±~ ? = * [ '~=j j?j±J° W j % ~ = X / X= /°%XK_° /[ ~ ~ ±W j ±= ~ ! — _ J ? X/^ W j _ ±J j ±h 4 ' ±~ ^ J ' ~ ^ / /'j ±j — _ X? W j ± ~ !

'

q1' &&

■Xh' O‘ Xh Xe X e5>ky■]^* ■^|(k] ■Wp* y*pW£*■’ ”cC£CZ

' X" 'B 4KU6ChU/ "^ X? K^ 0 7X_ ? /U ~ ^ ± ^ X ♦±~ — — ^ ~ ? ±^?hU CK /— '

/' X7] o / ~ ^ _ z 4±~X^ K ^ ] ± ~ ? ± ±G; X/ % ~ ^ = e < K%!gPK±h)l ~ ± j g- K h^ ? ? X±[ //4 / X — j ± 4 'j jhXX?_ 7± hU ±hXl±±X^X^[X U X/± 7 ±;Y±]]/ e»+ 4 X — j ± Z X+v 8 ~ / ; vh

/X/= _ ? _ ° = X= * [j '_;j _ % % Xj W /' j /J* ;_^j= !~^?W [ X/' — ^ ~ ? = /~ j*^_X\j /' j J _ X? = ~ ! /'j K_~ ±X— j /j ± /~ [ j±= * > ~ /' X? /'j w- _ ? W /' j q x , =jK /X~? h

gW ,j/j±—X?_/X~? ~! /'j j?j±J° =K_j=

g \W Ex2 2Y2;4G ^b*V2 » i ^x2 kh1i (2bV’K^

6 j W j /j ±— X? j W /'j j? j±J ° =K_j ~ ! /' j w- K _ ~ ± X— j /j ± =jK /X~? h cW _=

v d c a hTK— * E % j W !Y z J !s iG T m'

[ 'j±j K — *h % KW % ® _ ? W /J !“ _ ± j /' j — j _=^ ±jW =XJ?_* /'j % j W j = /_ _ ? W /' j /~ [ j± J _ X? K ~ ? = /_ ? / !~ ± /~[ j± ~ ! /' j w - K _ ~ ±X— j /j ± = j K /X~ ? * ±j=%jK /X;j ° * _? W kb X= /' j j ? j ±J ° ~ ! /'j j j K /±~ ? >j_— h w jK /±~?= [ X/' j ? j ±J Xj = ±_? J X? J !±~ — t /~ mts k j1 [ j±j ^=jW ! ~ ± /' X= % ^ ±% ~ =j * _ ? W [ j =^ — — j W W Xj =XJ?_= ~;j± _ t ] c — _ /±X] ~ ! K _ ~ ± X— j /j ± ~ [ j±= =^ ±E±~ ^ ? W X? J /' j /~ [ j ± 'X/ >° /' j > j _— %_±/XK j=h

B XJh n =' ~ [ = /' j ;_ ^j ~ ! hEv _ = _ !^ ? K /X~ ? ~ ! /'j j j K /±~ ? > j _ — j?j±J° h 4 'j j ± ± ~ ± > _ ±= X? /' X= !XJ^±j* _= [ j _ = X? /' j !XJ^±j= = ' ~ [ X? J /' j ' _ W ±~ ? XK K _ X> ±_ /X~ ? K~?=_?) =h _ ±j W ~ — X? _ /j W >° /' j j!!jK/ ~ ! _ = ° = /j — _ /XK ^ ? K j ± /_ X? /° X? /' j J_ X? = ~ ! /'j

mnm


contributi,ms from tho.: neighbor, dc:pcnd on the: i:nc:rgy. the impact point and the: type: of beam particle. In orc!c:r h> dc:t.:rmin.: the total ,ig11.1I. it 1s crucial that the gains of all lhe lowers concribuling 10 th.: si!_!nal be: equal

\Vhc:n electrons were ste.:r.:d into the cent.:r of a calorim.:tc:r to,~c:r. they dL-pt>sll.:u I) pically more than 90°. of their c:nc:rgy in 1h;11 tow~r. Elc:ctwn, ,rnuld t.hc:refon: b.: wc:ll ,.uit .. -d 10 .:,,iualuc the ~aim of thc: EM cal,,rim.:tc:r l<lWC:l'\. Hm~e\c:r. during the: bt.':lrn tc:st_; only a lim11c:d numl'>c:r .if lu\\c:rs wc:rc: C:'tposcd to dc:ctron bc:-am,;. :--iol all ,:al,1rirnc:1c:r towc-rs could thc:rc:fore b.: calibr.itc:d this \\'1~-

Thc: onl) l)pc: of partid.:s that ,1c:n: ,.;Ill into c-.1d1 and """.:ry w-...:r of the c':l!urimc:lc:r ,1en: muons. Since 1hc:se muons d(p<1·m an .:qual am,,um ,,f i:n.:rg) in .:1..:ry ll'w.:r 1:ilkr wlmg 111w

a,-count the effi:cts cumin!_! from Jiff.:rc:nces in path lc:ngthl. th.:) ,-an b.: u"c:.l 10 1.'\jualuc: thc: ~ai11" of 1hc: towers. \V..: tit 1hc: ,ign.11 di,1r1hu11ons (in .-\DC ,Llunts• frur:i muuu,- in .:-.11:!t E:\I and c-.u:h H.-\D ,alurimc:lc:r 1m1.:r -..uh .1 Lindau fum:uun and d.:1c:rmmed the mo5I probable: signal \.uuc: for c-.11:h dis.trihuti,,n. All PMT ir.i.in.-1 \loere normaliLJ:d lu lhu,c: LlfW::dgc: I. To\\er ~ (-...-c: Fil,!. I 1. Thi" v.a:,

done: sc:par.11dy for the EM .ind 1J1e HAD h.,w·er.;. The: most prob-.iblc: 1·aluc: of the: signal Ji,tnhuuon from E.\I ,.,wer i ..,a,, rnullipli1.-J by a ··1m1cr g:iin cons Ian I tg, ·• so that all EM 10111.:~ =ponded to muon" hkc: th.: E!\.I 'i<.i.:lmn of the rcf.:n:n .. -.: 10111·cr. Thc: sam.: pm1:.:dure was follo-..,-d for lhc: lowc:n from the: !udroni~ c.J'-,run.:lc.r ,o;tiun. ""hi.:h lhu-, all r.:spond.:d to muons in lhe ,;ame \\-a} as the HAD 'i<:Clion l•f Wedge I. fowc:r 8.

We: vcriticd thc \"alidiry of this prOCl:durc for th= 10-..er.. lhal had bcc:n exposi.-d ro c:kctron:;. Fig. 2 shows thc rg, values found \\ilh muon., ploued vc:r.1L, the: 1g, \-alue,. found with ckctron:;. for all EM c-.dorirnc:1,:r lowc:rs. that had been l!llP<™--d to both t) pc!> of particles.. lkci.usc of the strong correlation betwc:c:n t~ two ~I\ of constant>. \\"C condude lhal thc gain con;,tanis found with muons (which depus1l typically only U.J Gc:V in the: EM ..-alorimc:1c:r 1owcrs1 are also \alid for the signab from shLlwc:ring ,:t._i.;tron'l. whose: cnc:r1,,y deposit is l}picall) l\10 ordc!'i of ma!_!nitudc: larger. Throughout the remainder of

131

!.!..-------------------,. -~ " ~ I.I

:: = 1.0 ;;. ... " 1 O.•I

/

,..,

. ,-., , .. , . . -:··,

~-.... . ...,, ... ., I • •

,-' I ,.--'' .

,

o.,"-------------~-....... --~-,u, l.U 1.: I ~

t-11 .!. r .. ,"'.,. ~;Jin ,_,,:ur:.J:ar:t, f-.,u:..J ~·rum mi:, 1 r:. rur .. , \11,,*f,1~,

t!:...: !uc..:i.J :"rom t:!&.~:ron Cl,,j.r_,. ~l f"nu: 1crn::-ic:::l~ .... ni: E\I ~:.ll,,nn\4:t.:r :u"'c:r The 1.uru. .1r.: r-L~rn1o1.lui.;J .-1:~1 rt.~ra.,: ~,, r ..,,,.c: " ,,!' \\·'"~n: 1.

!Im analy~i~. 11e ha\c applied the l~, 1aluo found ·.1i1h muon., lo ,:4u.tli1c: the ~in,- of1he ~-alonmcl.:r 10\\,:r.. both in the E.\I and thc: U.\O sc:cuon.

-I. I. 111.: •·m:rgy 1<"<1!.· of th,· EJI w,·ru•n

Wc dc:tc:rminc:<l lhc: .:ncr~y s.:ak of the EM calorimetc:r s.:..-tion. A. as

< .. tc:m, - pc-d""')tl!"', ") A - -· I -

Ee {I)

where em,. pc:d;"' and It,"' arc 1hc: mc;uurcd ~ignal. the: pedob! and thc 10-..c:r gain corutant for 10-..er 1 of the: EM calorimc:ter ,;c:ction. respc:cti\c:I). and ~ il> thc encr!!v of the: ekclron beam. E!..i.:1run,wi1h c:nc:r~o r.ingini; from S to 180 GcV wc:re u~ for this purpose. and we: summed the: -.ign.ils ol'er a 5 x 5 matrix of c-.!lorimcler lowc:n surrounding thc: lo\\ .:r hit by the: bc::un partidc:s.

Fig. 3 shows the valuc: of .-f as a function of the dl.'l:tron b.:am en.:rgy. The error hars in thi.s fi!,!ure. a,; wcll a:, in thc ligurc:s !>howing ta.: hadronic c-a!ibr.ition coiutanl,. arc dominated by lht: c:11<.-ct ,,f a ,ystcmatii: uncertainty in lhc: gain:; of the

n5r CF L } $> 0 N 0 ' — N <% i M R5<0q0 °*1<0R<*NS N$ q * % C>La u¥p] S k > 6 N R 1 E d N— R * > } suJ Z°}]J A WW[ * E X x

d QE ■ ■ © # © E E E E E E G E

+ UN U0 ]>P 7»w]]7° kd1 X

(X9h n 4'j K? K /7±° !~ ± /' j w - K _ ~ ? — j /j ± 9 ] X — ± h }■ _ = _ !^ ±] K ^ — ~ ! j?j±J°

L- 4 = W ^ ±X? J /' j > j _— /j=/=h [ 'XK' [ _= j =/X— _/jW _ / X“A»h Q /' j ± =~ ^ ±Kj= ~ ! ^ ? K j ± /_ X? /° X? W ^ W j =/_/X=/XK_ j ± ±~ ± = _ ? W j ±±~ ±= W j ±X; X? J !±~ — /' j J_X? j* ^ _X\_ /X~ ? % ±~ K j W ^ ±j T=jj Z jK /X~? nhuh LXJh q ~[ j=j±h =X?Kj _ ?jXJ'>~±X?J /~ [ j±= K~ — > X? jW Jj?j±_/j /°%XK_° ~? ° E v TL X ~ ! /' j = XJ ? _ = !±~— j jK/±~? =' ~ [ j±= * /' j j!!jK/ ~ ! /'j 8 //j ± =~ ^ ±K j ~ ! ^ ? Kj±/_ X? /° X= ?jJXJ X> ° =—_h Q ^ ± ±j =^ /= ='~[ /' _ / /'j ;_ ^ j ~ ! hm X= K ~ ? = /_ ? / [ X/' X? /'j j] %j±X— j? /_ ^ ? K j ± /_ X? /Xj = * ~;j± _ [ XW j ±_? J j ~ ! j jK/±~? j?j±J Xj=h 4 ' j [jXJ'/jW _; j ±_J j [ _= !~^?W /~ >je *m < va Z hv " s hc K /= k j1 T h 1 m E phZv < Tmhsn - j1 % j ± x , g K~ ^ ? /'h

gWhW pp7j 2Y2;U*G (bUm2 „3 ^x2 .cC (2bÛ„Y

gWhW=h hm A2^x„m \v? /'X= — j /' ~ W * [j ^=jW % X~?= =j? / X? /~ /' j w-

=jK/X~? ~ ! /' j K_ ~ ±X— j /j ± _ = /' j > _ =X= !~ ± W j /j ±— X? X? J /' j j? j ±J ° =K_j ~ ! /' j q x , =jK/X~? h 4 ' j %_±/XK j > j_— = [ j±j =/jj±jW X? /~ /' j K j ? /j ± ~ ! 4 ~ [ j± Zh 6 jWJj v T% ~ X? / /] X? B XJ h v' * _ ? W ~? ° % X~ ? = [ 'XK' % j ? j / ±_ /j W /'j w- =jK /X~ ? [ X/' ~ ^ / ^ ? W j±J ~ X? J _ ? ^ K j _ ± ±j_K/X~? TXhj hh [ X/' ~ ^ / = /_ ± /EX?J _ ='~[ j±' [ j±j =jjK/jW !~ ± /' X= % ^ ±% ~ = j h 4 'j j?j±J° =K_Xj ~ ! /' j q x , =jK/X~? h T]W [ _= /'j? Wj!X?jW _=

* d — C>,cJR * •kJ"Y—~)TY 'X E # ©h Ta'

[ 'j±j ' _W ** % j W !UUm _ ? W /J !U m _ ±j /' j — j_=^ ±jW = XJ?_* /'j % j W j= /_ _ ? W /'j /~[ j± J _ X? K ~ ? = /_ ? / !~ ± /~ [ j ± U ~ ! /' j q x , K _ ~ ±X— j /j ± =jK /X~ ? * ±j=%jKE/X;j°h k X= /' j j ? j ±J ° K_±±XjW >° /' j % X~ ? = h [ 'Xj k26 _ ? W =U9 W j ? ~ /j /' j j?j±J° W j % ~ = X/j W >° /'j — X%EX9j % X~ ? X? /' j w- K _ ~ ? — j /j ± =j K /X~ ? _? W

/' j j? j±J ° j_9X?J ~ ^ / /' j > _ K9 ~ ! /'j K _ ~ ±X— j /j ±* ±j =% jK /X; j ° h 4'j _ //j ± /j ±— X= j?j±J° W j % j? W j ? /h

6 j ~ > /_ X? j W w Y * ! ±~ — /' j =XJ?_= % ±~ W ^ K j W >° /' j % j? j /±_ /X? J % X~ ? = X? /' j w- K _ ~ ±X— j /j ± =jK /X~ ? h 4 ' j _;j±_Jj ; _ ^ j= _ ± j X=/jW X? 4 _ > j m !~ ± /' j ; _ ±X~ ^ = % X~? ±^ ? = /' _ / [ j±j ^=jW X? /' X= K ~ ? /j = / h 4 'j=j K~;j±jW _ ? j? j±J ° ±_?Jj !±~— t /~ m A s k j1 h 4 ' j K _ ~ ±X— j /j ± — ~ W ^ j X= _ > ~ ^ / W j j % _ / 4 ~ [ j± t h 4 ' X= X= ? ~ / W j j % j?~^J' ~ !^° K ~ ? /_ X? /' j 'XJ'Ej?j±J° % X~ ? ='~[ j±=h v? ~ ±W j ± /~ j = / X— _ /j /' j j?j±J° j _ 9 X? J ~ ^ / !±~— /'j > _ K 9 ~ ! /' j K _ ~ ±X— j /j ± * [j ^=jW j] % j±X— j ? /_ W _ /_ /_ 9 j ? >° /' j 6 x g ~ _ > ~ ±_ /X~ ? _ g w 0 P DZV* 4'j° — j _ =^ ±j W /' j _;j±_Jj j?j±J° !±_K /X~ ? W j% ~ =X/jW >° =' ~ [ j ±X? J % X~?= X? j _K ' ~ ! mu K~?=jK^ /X;j X±~ ? % _=/XKE=K X? /X8 X/~ ± =jJ — j? /= * !~ ± % X~?= [ X/' j ? j ± EJ Xj= ±_ ? J X? J !±~— ms /~ mnp k j1 h Q ? /'j >_=X= ~ ! /' j =j W _ /_ * [j j=/X— _/jW /' j wX~; ;_^j= X=/jW X? 4 _ > j v h

4 ' j _ =/ K~ ^— ? ~ ! 4 _ > j v X=/= /'j ±j =^ /X? J ; _ ^ j = ~ ! /' j K _ X> ±_ /X~ ? K ~ ? = /_ ? / !~± /'j ' _ W ±~ ? XK K _ ~ ± X— j /j ± =jK/X~? h t *h

B XJ h u ='~[ = /'j ;_ ^ j ~ ! Z X ~ > /_ X? jW X? /' X= [ _° _ = _ !^ ? K /X~ ? ~ ! v'j j?j±J° Wj%~=X/jW X? /'j ' _ W ±~ ? XK K _ ~ ? — j /j ± =jK /X~ ? >° /'j % j ? j /±_ /X? J % X~ ^ = h P ~ /j /'j ~ J _ ±X/' — XK =K_ j ~ ! /'j ' ~ ±X\ ~ ? /_ _] X= h 4 ' j ;_ ^j ~ ! !X X? K ±j _ =j = [ X/' j?j±J°* [ 'XK' — j _ ? = /' _ / T'j T' _ W ±~ ? XK =jK /X~ ? ~ ! /'j' K _ ~ ±XE— j /j ± X= X? /±X?=XK_° ? ~ ? X? j _ ± !~ ± %X~? W j /j K /X~ ? h 4 ' X= ? ~ ? X? j_ ±X° _ — ~ ^ ? /= /~ E v \ mm [ 'j? K ~ — E% _ ± X? J /' j ~[j=/ _ ? W ' XJ ' j =/ % X~? j?j±JXj= ^=jW !~ ± ~ ^ ± /j=/=h

gWhWhW w2^x„m :v? /' X= — j /' ~ W * [j ^=jW j j K /±~ ? = [ 'XK' [ j±j

W X±j K /° =j? / X? /~ /' j q x , =jK/X~? ~ ! W Xj K _ ~ ± X— j /j ± /~ j =/_> X=' /' j j?j±J° A =K_j !~ ± /' X= = jK /X~ ? 6 jWJj n ~ ! /' j K _ ~ ? — j /j ± /j =/> j_— — ~ W ^ j [ _= >^X/ [ X/' ~ ^ / _ ? w - =jK/X~? * _ ? W /' ^ = — _ W j X/ %~==X> j /~ ^ =j /'X= K _ X> ±_ /X~ ? — j /' ~ W h 4 ' j j jK /±~ ? > j _— = [ j±j =/jj±jW X? /~ /' j K j ? /j ± ~ ! 4 ~[ j± Zh 6 jW J j n T%~X? / /L, X? B XJ h v 'h 4 ' j j?j±J° =K_ j ~ ! /' j q x , =jK /X~ ? W j /j ±— X? j W [ X/' /' X= — j /' ~ W h y ^* [_= /' j? !~ ^ ? W _ =

G d qh'_WX E %jWYqJY '

mna


.II .-tJJ,,,,.. ,r "' / .\"u,:1,-ar ,,..,,_,.,, ..,,J .11~,ltu.h u, Ph,·ri.1 luJNrrn ., ,:e, :flll.' 1 1.,1 -195

(i ~ '"'I

;- -.---- ·-. --· ··--· ....... ___ .... -----

-< t IIU'--------------

iUJ '..Oft .:r•t E:,,:'l~1G<V1

F1~. _i fh..: ~:11."f!) ~~ :·L,r t!'lc: E~t \.'"a.OnrDl..wfC't' .n.1.h,r.. A . .1:1 J.

:"ur.L:wn o( C\cC#)

P:1.IT, during the beam lest-. whi.:h wa, .:stimat.:<l al i •·., Othc.-r soum."5 of unccrtaint} indu<lc: ,1.uisli,;aJ c:rmrs am! cm.>r, dc:ri\ ing from the: gain c:qualiLation pnx-rourc: I'>« Sc:ction }.-l. Fig.::,. Howc\cr. sin..--c: all nc:rghboring towcrs .:ombmcd gener.uc: 1~pi1.,tll~ only ~ tw·, of thc: ,ignab from c:l.."\."tron \howers. thc: .:11.-ct of thc wttcr sour.:c: of nnccrt,nnly 1, nc:gligihl~ ,mall. Our roult,; ,how that the: \.Uuc: of . I " constant l'ithin the: .:xpc:nmc:nlal un.:eruinti~-s. ovcr a w1d.: range: ,1f c:lc:ctrun c:nc:r~ics. The WC:l!!hl<!\l a,c:rai:c: wa, ti.,und In he:: ,-I ; I ::iu .:: U,5 :ts ·Gc:V 1.-1- 1 ~ 7.li I.::

ll,0.\ :l.t.:V fl'-"!' .\DC CUUnt).

-1.l. TT,,: t:nerq_r ,ca/,: ul the: lf..1D s.:L·twn

-I.:!. I. .\fetlwd I In thi.,; mc:thu<i. we: u!>C:d piuns ,cnt into the E~I

sc:cti,>n of thc: calorimc:tc:r as the: has&\ for dc:terrninin~ lhc: c:nergy ><:ale of thc H,\D So!\.-iion. The partide bc:ams ,,.er,: s1c:cr.:d iulo thc: cc:nLC:r of Tower li. Wc:dg,: I tpoinl P1 in Fig. I). and only piom 11ohich pc:nctr.uc:d the E.1\1 ,c,:tion .,.ilh,mt undc:rgning a nuclear l'\::11.-tion (i . .: .• without ,tarting a 'lho.,.c:rl \l.c:rc sc:lccrc:d for this purpose. The c:nc:rgy s.:alc of the HAD section. 81, was then dclin.:<l a.\

., ) ,f had, - pcd!'-'-1 )ll!ho.l ·, n, = ' -· · -· · c11 < £. - E«,. - £1c,t)

whc:re had,. pcu;"4 and 1~ arc: thc: mc:asurcd signal. th.: pcd .. -s1:i.l :ind the tower gain constant for tower i ,>f the HAD calorimctc:r sc:,."lion. n:sp..-cli\·cly. £, is the: c:nc:rgy <.-:irnc:d by the pions. whilc: E.a,, and E:,,t denote the energy Jeposilc:d by the: mip-li 1.:c: rion in the El\! calorun.:tc:r s.:ction and

132

lhc: energy Icaling out the: had, of the caJorimcta:r. respc:cti,cly. The l:lllcr term is c:nergy dependent.

Wc obuinc:d E.,.... from the: )ignab prudu1."Ctl by the: pcnc:traring pions in lhc: EM calorimeter ..:.:lion. The an-rJgi: ,alu.:s arc: futc:d in Tabk I for the \arious pion runs that wc:re ~ in this contc:11. These: cu,crc:d an <."flcri,,y range: frum 8 IO

I 70 Gc:V, The: •-alorimct.:r mutlule i, about s; . ..,, d1.-.:p at To.,.c:r 8. Thi,, is not d.:-.:r cnuu!!h lo full)· 1.-ontain the high-..:ner!!~ pion shu\\ers. In ordc:r ll.1

.:stimatc: thc: encri;y le.1lm!! oul from lhe lvad.. of the 1.-Jl0rimc:tc:r. 11,,: 1is,:d c\pc:rimc:nl;tl data ta.ken hy the: W.-\l Collah,,rati,,n al CER:-. [SJ. The:~ m .. -:LSur .. '1.l the a\·er.1gc: c:nc:r!,!} l'r.u:tion dcpositcJ b~ ,hll\\,:nng pion> in each of l-l <.-OlbL'\:ut1\C: iron plastic--..:intill.11,,r scgmc:nls. for pi,ms wuh c:nc:rg1 .. "S rangm!! from IO 10 I y; GeV. On th.: ba,;i, of rhe,c d.11.a. •,\c: e-;1ima1c:J the . Ei.:,, · ,aluc, li,teJ m Table: I.

The: la.,t column of T .1,hlc: I li,u the: r1..,.ul1in!: ~a!uc:s of thc: L":llibrati,,n ,on,tant for rhc: hadronic 1.-:iionm.:tc:r 'i<."Cllon. 81 .

Fig. -l ~hlm·s the: value of Br ohrainc:d m this \\ay a.s a functil•n of the cn.:r~) J.:po,11~J m thc hadronic .;;1l,>nmclc:r ...:cuon h)· thc pcnc:tratingpion.,. ;'1;,,rc: the: loganthm1.: s..--alc: of 1hc: honzon~,1 a.\i,,. The \aluc: of 81 in1.,-c:-.uo \\llh encrln'. "'hich m..--ans 1ha1 the 1haJronic s..·,:ti,~n of 1hel .-aI,,nmc:ter rs inlriru;i~-all) non!iru:ar for pion Jctc:ctiun. Thi, nunlinc::mty amount,, tu - IO"~ \\h,:n 1.·umparin!,! the: lo\\ol and h1~h .. ~1 pi,•n .:n.:rgic:s u_~

for our 1 .. -,,1~.

-1.J. :!. Jlerh,,J II In this method, \\e used drxtrons \\hich wic:rc:

directly sc:nt illlo th.: HAD sc.:tion uf the .. -atorimc:ler lo l!!l!abli.\h lhc: energy "'--,lie for 1hi,,

secuon. w~'dge J of th.: calonmc:1.:r testbc:am modulc: ~as buih without an E~I ,cction. and thus mad.: it pos.>ihlc: 10 use: thi~ calihrauon mc:lbod. The el..-ctron beam.:, w.:re ~t.:cr.:J into th,: ccnlc:r of Tm\cr S. WeJ!lc: J (point P; in Fig. I). Th.: c:nergy sole: of the HAD s.."\.-iion d.:u:rmir. .. -tl with thi~ mc:tho<i. Bu. \\as then fowid a.\

, }]v0£N_ —N qp N WNN5dq0 N*1N0RS—*R d—+i dNN>S<1 [ k>61<51 I—1—q05> } s■.r .jQByr EE]]*Eb :

4_'9 I">— _ ; j ±_ J j j Y ° zK % ~ =? _ X — /'j w- K/!~?/~jXj± XKK/X~?* X!KK _;j±_Jj K_j±Y 7 AhK_9X?J ~^X /'j >///9 £° /'j K_~±X—j/j± _X^ /'j x ;j±_Jj

j ±] ±7° Wj%^+X/K/X X= /'j '~/X?jUo K~z^?—jXK± XKK/X~_ _?e '+/_ 4~± %/E_j/±_XK7 %/~j= _ ! zX/4X±!j?/ K=j±%KUh x Kj j ±% j X _ X± %;j_ X? ~?/U ~! kj1h ± U ±j=^^_J ;~XKj ~! /'j K_X>±_^~j K~±^/~?X !~± /'j '~W±~jUe K_X~±??j^! »K^~j h onB ~ ~MX~X — /'j > ' K~^—?

L X~ ? j ? j ±J ° ■ h " » A x U j A■ E "m* E " $ » E Z oQ 9 " + hg K 1 '

Zh- QzEQhv s z8±Aq muumXehe ~7U_X ~ X Xhb+~ X F1eeaz+h4 ? / E X h /+ u XQ hv l hs EUl hv± U X v > E ^ z c r /'± U+n mcmu&» hn s n E s m m r heE X- mcr /E+■l s n ■ s hm mrs u E m s hAZ hX

a

hQX

! X X u 4'j KK K ] j ; [ _ j h♦~ ! /' ] ' _ W ± ~ K X] K^ X»2 ^?K /K± [ KÛ±( /!h _l _ ! ^ = 9 / X~ ? ~ ! j ? j ±J ° * ! ~ ± /' j /' ±j j =_ z X' ±_ 8 ~ _ ±_K X' K] 8 ^_KhX X? /= X+ _? _ l Ñ\ Z ± ' K _?»±U /' ± ~ ^ J ' /' j j ] % j ± X— j ? /_ % ~ X? / X _ ±K W ± _ [ = ^l J ^ XW j / ' j j Cj h Z jj / K X / !~ ± Wj /_ XU h

[ ' j±j ' _ W ** % j W U Y _ ? W XJ!UE _ ±j /' j — j_=^ ±j W = XJ?_* /' j %jW j= /_ _ ? W /' j /~ [ j± J_ X? K ~ ? = /_ ? / ~ ± /~ [ j ± X ~ ! /' j q x , K _ ~ ± X— j /j ± =jK /X~? * ±j =%jK /X;j ° * _ ? W w E X= /' j j? j±J ° ~ ! /' j j j K /±~ ? >j_— h

!EzjK ±~ ? = [ X/' j ? j ±J Xj = ±_ ? J X? J !±~ — m m /~ mpp k j 1 [ j±j ^ =jW ~ W j /j ±— X? j /'j ;_ ^ j ~ ! !X? h [ ' XK' X= =' ~ [ ? _ = _ !^ ? K /X~ ? ~ ! /' j j j K /±~ ? j? j±J ° X? B XJ h uh 4 ' j ; _ ^ j ~ ! ! X$ [ _= !~ ^ ? W ~ >j K ~ ? = /_ ? / [ X/' X? j ] % j ? — j ? /_ j ± ±~ ± = T ± E AEm' !~ ± _ [ XW j ±_ ? J j ~ ! j?j±J Xj=h 4 ' X= ±j!jK/= /'j X? /± X? = XK X? j _ ±X/° ~ ! /' j q x , =jK /X~? !~ ± j j K /±~ E— _ J ? j /XK = ' ~ [ j ± W j /j K /X~ ? h 4 ' j _; j ±_J j ; _ ^ j [ _= !~ ^ ? W /~ > j = XJ? X!XK_? /° ' XJ ' j ± /' _ ? /' j ;_^j=

!~ ^ ? W [ X/' - j/' X] ve !X? E mpnhc j = iQ K 1X! X * * A ■ chp' x , g j=* k j 1 +h

sBtBtB ,—N>£% ::]x = X? - j/'~W vh % X~?= =j? / X? /~ T% ~ X? / L * ~ ! X

/' j !K- K _ ~ ? — j /j ± =jK/X~? [ j±j ^=jW /~ W j /j ±— X? j /' j j?j±J° =K_j ~ ! /'j ' _ W ±~ ? XK K _ ~ ±X— j /j ± =jK /X~ ? h q ~[ j;j±* /'X= /X— j /'j K _ X> ±_ /X~ ? K~ ? E= /_ ? / h !? Xh [_= K'~=j? =^ K' /' _ / /'j j?j±J° ±j K ~ ? = /±^ K /jW !~ ± % j ? j /±_ /X? J % X~ ? = [ ~^W >j j * ^ _ ~ /' j j?j±J° ±jK~ ? =/±^ K /jW !~ ± ? ~ ? % j ? j /±_ /EX? J % X~ ? = h v? ~ ±W j ± /~ _; ~ XW /'j j !!jK /= ~ ! =' ~ [ j± j _ XEXJ K h [ 'XK' [ ~^W %±X— _±X° _ / j K / /'j ±j=^/U !~ ± /' j % j? j /±_ /X? J % X~?= _ ? W /' ^ = > X_ = /'j ±j =^ /= * [ j ~?° ^=jW ~[Ej?j±J° ehl k j1 ' % X~ ? ±^ ? = /~ !X?W /'j ;_ ^j ~ ! !X— h [ 'XK' ? jjWjW /~ =_/X=!° /' j K ~ ? W X/X~ ?

■e 1 /' _ W h E % j W ® 7 / Z! l

cQ[WZ;;;;;;;;;G ?~/A~%K? E

X) hXK — * E %KW!—'/J!U E T'_W * % K W Y / J Y l

wXTu'

4 Xj _;j±_J j ;_ ^j !~ ± [ 'XK' /' X= K ~ ? W X^ ~ ? [ _= !^ !XjW [ _= !~^?W /~ >je !— f mZrhc K /= ik j 1 T!X!$o f chcr x , g K /= ik j 1 'h 4 X?= ±j =^ / X= _ =~ X? K ^ W jW X? BXJh uh

gWRW £2b„Y(^;’b^2m 2Y2;4G 3„; x*m;„Y( *Ym [2^(

q _ ; X? J WX=K^==jW /' j ;_ ±X~^= — j /' ~ W = /~ =j/ /' j j ? j ±J ° =K_ j ~ ! /'j ' _W ±~ ? XK K _ ~ ±X— j /j ± =jK/X~? h

mnn


.I/ ,l/1,rc,... rt .Ji. 1 .,·,,.1,.u f,u1,,_,, .,,.., 1/nhu.b 111 /'h_vnc, t&-,ch A ,,,; , :u;_• • Ml -19:S 3!!7

T.able I ~ .lV~U~ =cr¥)I Jcr-mtoi in th&, EM ""1una>eter -....~on, 1hr ,.~.,.._.g,., CtlC'!) :eabllj "1111be t>.oo:k <>f 1M .:u.>nnictct .,nJ the ,...,._.IV ,r.rfJY Jq,uo,«.-.1 •• t~~ !:;u!n..,,.; ~ ...,_"ti,.., = :..1.:J for P<-n.:tr-.au::i I"""' .,r Jitft-rcnt .::zrp:1 . .-\II """''JIC' = jt>Yffl ,n aruu <)( G.:V. 1% n:suJun~ \".UC.: '1( the ""1ibr.UWCI .:or1>·u.,u f,lC' the baJto""' c:alonmi,t..'f -'Cl:IIOC. B,. 1> :t.lCII 111 :he !.l;i Cl)IUfflD

P\un cni:r~ ·.E.-

!.1>-1 I• •

~-~

~·J ••I .l -.·,·1

OJ=•ll O.J::lll O} :0.1

II~:: !I. I I) 3 ::ll I 1); .:0.1

::o,~--------------

'"'

t-O

' ---------- -------

,_ __ ___ ----···-t------,--·

~1· . a::i I · ilu j'

1:11.___ __________ ~

-·c..a.·, I)

0

II~ :V.I I b:.n_t

J ".:.•J ., 10: :::o

t: Ill \cl .CII \oll

En,:rr> C(c\-l

hi. -' The::~~:- -:.ak :~,, :r.c :~rllru...- i:.a.,-rufk."':rr ,~-:u-r .. 8. .o .a fu.-:...uor. ,.if I!~:,'. for :h.4: :trtt wlahr.da-.>n mc:t."-.... ~ :.ac.,1 1n t!U., ..an.al~-..... 1:-..e :.:i~ ~hro~i,!b ;he ~,,-..fUJ:.&.-nr..; rv11:~ Jr.: Jr,u1.-: tu gi;.1.J.: tt-.c .:,~. S.:C !..",-t for lk:.ub..

where had,. ix-d~ and t!f,""' arc: the: m .. -:isun.-d signal. the: p,:<lotal anJ the h>Wc:r gain .:on,LU11 fiJr lo\\c:r i of thc: HAD calorimetc:r Sl!\."lion. ropc,;uvdy. and £: is Lhe c:nergy of the dc,;tron h..-am.

El.:ctroru. ~ith energic:s ranging frum 11 10 IT: G,:V "'.:re u.sc:d to dc:tc:rminc: th.: value of Bu. which i,, sh<>\\ n as a func1i,1n <>f the: d.:ctrnn .:nergy in Fig. -t The value: of Bu was found to be constant \\iLhin c:.xr,:rimc:ntal c:rror'> 1::: :'. o)

for a wide: r.ingi: of c:nc:rgi~. This r.:lla:u the: inLrinsic lini:-.1ri1y of the HAD >C\."liun for dc:\."tromagnetic shower detccliun. Th,: a,cr.ii,.,e value wa:1

founJ to be ,ignili.:anll~ higher Lhan Lh.: value,,

133

,:£.,-£..-£a1,·

U::•I I 11.9::•J I

=~-0 ::ll.1 ~6.0:.0J

'46.==I)"' I/OH~ :.o

l~.I tJ~ 5 1.a-.J l'I ~ I '6.1

f,,unJ

tBu'

,\1th :\kth,'ll! !· 8 11 •- 17}., cL,. GcV 5.-:'t, ADC ch.- <.ic\·,

-1.:.3 .. 11.-thvJ Ill ,\, in \kth.xl l. ('1,,11, ...:nl mto \,w,nt P! llf\

th.: EM .:a!,mmctcr ,._.,;111.111 "',:re usc:J t" Jc:tc:rmin.: the: cn.:rg~ '1\-:ilc of thi: hadmmc ,-al,,ramctcr s.:ctwn. 1-hmc:\cr. 1hr, umc: 1hc .:-alilirauon con,tanl. 8111. 11.1, dw,i:n ~ud1 that th.: cm:rg~ rc:con.,truc1.:d for pcnc:1raung ('ttln.~ \\OUld he: .:qu.al t,, th.: ..:ncr~) r,-..-..111.>lruct .. 'll for n,•nr-:n.:tr.11-mg pi,•ru.. In order tu ;irn1d th,: dfo:ts ,,f ~hll"'-« !i:-..1.L1gc. whu.:h would pnm.irtl) .iffo:t th.: r,=,;ulL, for th.: pen.:tr:itmg r1,1ns and thlL, hia~ th.: resulL,. \\Con!~ lL"'--<l low...:n.:rg) 1-:: ~O Gc:\'1 pion run~ to rind th,: valu.: of B111 • "tuch n«di:tl 1,1 -ausf) the: conditwn

· \ - tlud .....1•....i)lc1>J , £1.'Cfl - ·. -· ' - .~~. _, ' 111 - E, - t:,~ = n;'i;',:,<:I

'. ,-.,cm, - p,:J:..,,.Hg;""' - (haJ, · p..-d:u-i11~ > £.

(•0

TI1e '1\Cr.ll,'1: ~alu,: (ur "hi..:h lhis comiiuon w.c. fulfilled wa, found IO he: 8111 = IS6.5 ,:ts/Ge\' I 8 11/ = 5.J6 ADC ..:t.s;Gc:V). Thi,, ~ult is ab,, included in f-ig. -'·

-1.J. Rc:wrutn1<·c~d eneryy for huJrvns ,mJ jec.s

Ha11ing disc~ thi: vario~ m.:lbo<ls lo sc:t the: c:nc:rgy seal.: of th.: haJronic 1.-alorim.:1.:r ><!\:lion.

»<:B }E90R^ 5N =VB [ MR%Sq0 [S1N0SN—*N< qS< <<5 <>R N> ? k>6q51 I—N5q05v . sMr . h 6 z tM. * W Nt

[ j K_? ? ~ [ W j /X?j /' j ±j K ~ ? = /±^ K /j W j?j±J° !~ ± _ J X;j? ' _ W ±~ ? ~ ± 7j / _ =

Tj±_* E % j W Y / j ! £"N<~ f Hl ® EEEEEEE

T ' _ W * E % j W Y / J . E m EEEEEEEEEEEEEEEz a G T c ’® v z 8 v v

[ ' j ±j _ =°— >~= ' _ ; j /' j =_— j — j_? X? J _= > j !~ ±j h v ! [j K ' ~ =j - j /' ~ W v /~ =j / /' j j?j±J° =K_j ~ ! /' j q x , =jK /X~? * [ j [ ~ ^ W ? jjW /~ =%jKX!° /' j j ? j ±J ° _ / [ 'XK' /' j K _ X> ±_ / X~ ? K ~ ? = /_ ? / !* [ _= W j /j ±— X? j W * =X?Kj /' X= ; _ ^ j X= j? j±J ° W j % j? W j? / , j% j? W X? J ~ ? /' j j? j ±J ° * /' j ;_ ^ j ~ ! T — _° K ' _ ? J j >° _= — ^ K' _= m s “ h T=jj 4 _> j vh BXJh u' 4 ' j ~ /' j ± /[ ~ — j /' ~ W = _ ±j > _ =j W ~? j ?j±J° E X? W j % j ? W j ? / K _ X> ±_ /X~ ? K ~ ? = /_ ? /= h v? % ±_K /XKj * [j ^ =jW _ ; _ ^ j E mc mhu j = kj1 !~ ± ~ ^ ± = /^ W Xj= ~ ! W Xj X— % XK_ /X~ ? = ~ ! - j /' ~ W vh Xhjh /'j ;_ ^ j ~ > /_ X? j W !~ ± /'j cr k j1 % ~ X? / _ ? W _? _ % % ±~ ] EX— _ /j _; j±_J j ~ ! _ /' j ; _ ^ j= ~ > /_ X? j W ~ ; j ± /' j j?j±J° ±_? J j [j = /^ W XjW h

c h w ] % j±X— j? /_ K~?=j*^j?Kj= ? ! T— X=9±_X>±_/X~?

v? ~ ±W j ± ~ j ; _ ^ _ /j /' j — j ±X/= ~ ! /'j W X!!j ±j? / K _ X> ±_ / X~ ? —K'XlW]* [ j K ~ ? K j ? /±_ /j W ~ X /[ ~ _ =% j K /= e

v h TU*(2( )*(2m *Y ^x2 (^*;Û6^ !„UY^ „3 ^x2 (x*^^2;(W v? j] % j±X— j ? /= [ X/' ' XJ ' ° =jjK/X;j /±XJJj±= =^ K' > X_=j= _ ±j _ ? ^ ? W j = X±_ > j !j_ /^ ±j - _?° ; _ ±X_> j = /' _ / X?;~ ;j /' j ±jK ~ ? = /±^ K /jW ' _ W ±~ E? XK j? j±J ° TjhJ hh X' j /~ /_ /±_ ? =; j ±=j j?j±J° ~ ± /' j — X==X?J /±_ ? =; j ±=j j? j±J ° l j] ' X> X/ _ =/jj%°E !_ X? J W X= /± X> ^ /X~ ? h v ! ~ ? j /±XJ J j±= ~ ? /'j ;_ ^ j ~ ! =^K' _ ; _ ±X_> j * — ~ = / ~ ! /' j =jjK/jW j;j? /= _ ±j /' ^ = ~ K _ /jW ? j _ ± /' j /± XJ J j ± /' ±j=' ~ W h y X_=j= ~ ! /' j /°%j — j ? /X~ ? j W ' j ±j [ ~^W j _W /~ j; j ? / =_— % j= /' _ / _ ± j % ±j W ~ — X? _ ? /° % ~ % ^ E_ /j W >° j;j? /= /' _ / [ j ±j _ K /^ _ ° >j~[ /' j /± XJ J j ± /' ±j =' ~ W * > ^ / [ ' XK' ' _; j _ ^„!„V„^[K /' _ / > ±X? J = /'j— _ > ~ ; j /' _ / /' ±j='~ W h x = j] _— % j= ~ ! =^ K' /~ % ~ ~ J Xj = [j — j? /X~ ? j;j? /= [ X/' % X~ ? = /' _ / = /_ ± / /~ = ' ~ [ j ± W jj% X? /' j W j /j K /~ ± * ~ ± 7j /= X? [ ' XK' _ ? _ ? ~ — _ ~ ^ = ° _ ±Jj j?j±J° !±_K /X~ ? X= K _ ± ± Xj W >° °♦= !±~— h/♦♦ W jK_° hv ! /' j j?j±J° ~ ! =^ K' j ; j? /= [ j±j =°=/j— _/XK_°

~ ; j ±j = /X— _ /j W _ / /' j /? J J j ± j;j* /' j ? /'j K~ jK /jW j ; j ? / = _— % j = [ ~^ W > j > X_=jW h

ah .*m;„YUb (U^[6^V Y„YUUY2*;UVGW 4 ' X= X= _ ? ^ ? W j=X±E_> j ! j _ /^ ±j !~ ± _ ? ° W j /j K /~ ± * = X? Kj X/ — _° _=~ j_W /~ = ° = /j — _ /XK j?j±J° — X=— j _ =^ ±j — j ? / !~± K j ± /_ X? K _ /j J ~ ± Xj = ~ ! j;j? /=h q _ W ±~ ? XK =XJ?_ ? ~ ? X? j _ ? /; — j _ ? = * !~ ± j] _— % j * /' _ / /'j K _ ~ ±X— j /j ± = XJ ? _ !±~ — _ 7j / K ~ ? /_ X? X? J ~?j cs k j1 % X~ ? X= =° =/j — _ /XK_ ° _ ±J j ± /' _ ? /'_/ ~ ! _ 7j / X? [ ' XK ' /' j cs k j1 X= = ' _ ±j W >° =j;j±_ ~[ K±Ej?K±J° % X~ ? = h v? % ±_K /XK j * /' j W X!!j±j?Kj >j /[ jj? /' j =j /~ % ~ ~ J Xj = X= ? ~ / _ [ _° = j;XWj?/ !±~— /' j j ] % j ± X— j ? /_ W _ /_ h x ? W _ / /' j /±XJJj± j;j* = ^ K' j4jK/= — _° K_^ =j /' j =_— j _? W ~ ! > X_=j= _= W X= K ^ = = j W _> ~ ; j

v/ /^ ±? jW ~ ^ / / ' _ / /' j K _ ~ ±X— j /j ± % j ±!~ ±— _ ? K j X? /' X= ±j=%jK / X= * ^ X /j =j?=X/X;j ~ /' j K ' ~ XKj ~ ! /'j K _ X> ±_ /X~ ? — j /' ~ W h

K i >U6[V2 x*m;„Y(

WRW=W=W C2!2Ym2Y^ 2 „Y ^x2 (^*;^6* !„UY^ „3 ^x2 (x*^^2;(

6 j = /^ W Xj W /' j X— % XK_ /X~ ? = ~ ! W Xj ;_ ±X~^= K _ X> ±_ /X~ ? — j /' ~ W = [ X/' j; j? /= K~ j K /jW X? /'j Zh r k j1 % X~ ? > j _ — h 6 j =% X/ ±XXK=K j ; K? = X? /~ /[ ~ =_— %j=* > _ =j W ~ ? /' j =/_±8 ?J % ~ X? / ~ ! /'j ='~[ j±=e 4 ' j % j ? j / ± _ / X? J _ ? W /' j ? ~ ? % K ? j /±_ XX? J j;j?/=h

BXJh c = ' ~ [ = /' j ±j K ~ ? = /±^ K /jW j ? j±J ° W X= /± X> ^ E/X~?= !~ ± /' j =j /[ ~ j ; j ? / =_— %j=* ~ > /_ X? j W ~ ? /'j >_=X= ~ ! - j /' ~ W vh ^ = X? J T] < mcmhu K /= ik K 1 h 4'j — j_? ;_ ^j= ~ ! /' j =j /[ ~ W X= /± X> ^ /X~ ? = W X!!j ± >° mcR h q _ W [ j ^ =jW _ =— _ j ± ; _ ^ j !~ ± T]' j hJhh I u u K /= ik j 1 _ = =^ J J j= /jW >° 4 _ > j vh /' j ? /'j W X!!j±j?Kj > j /[ j j ? /' j =j /[ ~ — j _? ; _ ^j= [ ~^W ' _; j >jj? j; j? _ ±J j ± h

BXJh r = ' ~ [ = /' j = XJ ? _ W X= /± X> ^ /X~ ? = !~ ± /'j =_— j j; j? / = _ — % j = * > ^ / /' X= /X— j - j /' ~ W vvv '_= >jj? ^ =jW /~ K _ K ^ _ /j /' j ±j K ~ ? = /±^ K /j W j?j±J° Tc /? f vZrhc K /= h k j 1 Xh v? /' X= K _ =j * /' j — j_? ;_^j= ~ ! /' j ±j K ~ ? = /±^ K /j W j ? j ±J Xj = ~ ! /'j % j ? j /±_ /X? J _ ? W /' j ? ~ ? % j ? j /±_ /X? J % X~ ? = [ j±j !~^?W ~ > j j * ^ _ [ X/' X? /' j j] % j± X— j ? /_ ^ ? K j ±/_ X? /Xj = T_ =— _ !±_K /X~ ? ~ ! mR 'h 6 'j? - j/' ~ W vv [ _= ^ = j W * /' j — j_? ; _ ^ j = W X!!j ±jW >; E c R h

mnu


M. ,llbr,- n ,tl I .'iud.ar 1,ut,-,u, <ftl .Unl>oJ, 11 I'll_,_, Rr,n,rdt .4 ,1.,r, , .'1111! _ !:J/ .JII.<

we: can now detinc lhc rcconslructed energy for a given hadron or jct a~

~ '°' km, - p ... -d~ ll;f,'° E,a.uc L.,,,

' A

(had, - p...-d'....ilt~

Buuu 15_1

when: .i.11 1ymh~,1, h.i.,·c the -;amc: mc-.i.mng a., be for;:. If we cho'IC \k1hod I lo '\Cl the energy \Cale of lhc: HAD i<:l:li,m. we: would n ... -cd to ,pc...-if~ tl1.: enc:rgy at which the: calibrauun consunt 8 1 \\;t~

1.!.:termmed. ,in1..-.: thL~ , alue 1, cnc:rgy <lc:p,:ndcnt. 0.:pendmg nn the cncq;y. thc \·alue ,>f 81 ~I!< change by .i., much J.> 10·~ I.a: Table: I. Fig. 4) The othcr two rnc:tho<ls .i.n: ha.-.ed on cncrg:,inJcp,:n<lc:nl ..:alibraliun ..:oru.lanb. In practi<.--.:. \\C:

u..:<l a valuc 81 ~ 151 A cto. · Gc:V fur ,,ur ,tudic, of the impli<.-aUon. of Method I. i.e. the: value: obtained for the 56 Ge:\' l"''inl and an appr,,,. m~tc a\c:rJ~c uf all th.: valu<.-,, ublamc:d O\,:r tl1,:

In order to c:\aluatc the mc.-ril.s of the different ..-a!ibratwn mcth,~b.. we ... -om:c:ntrat...'1 on t-.,,o asp,..,..-is:

I. Biwa bt1.n·J u11 Ilic: Jtt1rti11,1 ptJ/111 u/ thc: sl,u.,·1:rs. In cxperimc:nb \\Ith highly .ck'\:tl\C: triggc:n \U.:h hia.,c:s arc an unJ,:,urablc: foature :l.lan!< ,·ariablo that inmlve the m.:on:strui:t,-d hadromc cncr1,•y (e.g .• the total trans\·,:rs.: cnerg~ or the: mi.-..~ing tr:m~vc:rsc enert,ry, .:.,h1bi1 a steeply falling distribution. If one triggers on the value of such a variablc. most of the: sc:Jc:ctetl c:vcnl!I arc: th~ 1~-aled nc-ar lhc: trigger th~hold. Bi.aso of the t!<(i.: mc.-nti.,ncJ hc:n: w"uld le-ad to ,:\ent samples that arc: predominantly populated by C:\ ettl.s that \\ere aclually below the trigger throhold. but which ha\·c: a !Opoloy_i tmt brin~ thc:m ahlnc: that thn.~hold. A:s examples of such topologies we mention c:\·enl!I wilh pion,; that ,tart to sho\\er deep in the dc:tcclor. or jets in which an anomalou.'1)· large: cnc:rin, fra.:tion b carried by ;•"3 frum :i'' d.:cay. If the c:nergi, of ,ul:h event~ wen: systcmati,:ally

13-!

o\crcstimatcJ at the: tnggcr le\"el, then the i:ollect ... -d ev.:01 '\ampk"!> \rnuld be biased.

~- Hudro,uc- ,iynul ,wn/ineurit_,._ This b an undc,;irablc fi:aturc: for any dct,:,:tor. ,in._--.: 1t may aho le-ad 10 sntc:matic enc:ri?\" mi.~mc:asurc:mcnt for <.l:rtaiu c=ategurio uf c:~-~nts. Ha<lwnic ,i~nal nonlineanty means. for c,ample. that the: <.-alorimetcr signal from a Jct containing one 50 Ge\" pion i.3 systcmati ... -ally larger than that of :11.:1 in wlm:h th.: 54) GcV i;; ,har.:d b!< ..:v.:ral lowcr-cncr!,,ry pioru.. In prJ.:ti<.--.:. lhe Jiffc:n:n.:c !-.:tw~,:n t11 ... -,,c: t<.>pologrc, 1s n,ll ah\ay., c, 1J.:nt frum the c:'l.pc:rimcntal J;ua. And ;H t!ic: trigg.:r !c\d. ,ud1 df1..-ct,, ma~ ~-Ju~.: the ,am.: lmJ of hia,ei as d1...:u.ss.:cl ahmc.

IL turn,..-d out that th.: c-.i.k•runch:r pcrform.i.n<."l: in th1> re>pccl 1, quite -.:mlll\C to the dwi.:c of the 1.-a!ibrauon method.

5. I Sln;1l.- h<1,lro1t<

5.1. I. Dcpt'11Jr:m t' ,,,, rlzr: ,t<1rtm!1 pv1i11 ,,,- ti:,· J/ro,rc:rJ

We: ,tuJic:d the 1mpli<.-.H1.,rL, of tl1c: \ari,,u, calibr:mon methods with C\ents colk._;tetl in the S.6 Gd" ;:ulln h.:an1. We split the:...: ,:,cots into two sampk~. basc:<l on the starling point of the: ,howel",: The: p,:n.:tr-ating and the: nonp.:nc:tratmg e,c:nts.

Fig. 5 ~how,~ th,: rc,:un~tru.:ted .:ncrg~ d1stnbu-1ion, for 1h .... ""S.: l\,o C:\.:a1 ~1mpf.-.;_ oh1arn.:d on lh.: ba.i.. of Method l. u.,.inl,! B, ,, 15 IA <:b: GcV. l1i,: rnc:-an \·aluc:s of th= two distrihuuons differ by 15~-•. Had we r.ucd a smallc:r \alue for 81 • .:.g .. 14-l cts/G,:V as suggested b~ Table I. L'icn the dilli:relk.'1: bct\loecn th= two mc::in \-a.lu.:s would ha~e bttn ,:\·en larger.

Fig. 6 \ht>\\S th.: ~i~-nal di,tributions for the same: C\Cnt ,;amp!cs. but this time: Method Ill has been iucJ to c-.ikulat,: the: r,"l:oru.tru..:ted enc:rgy 18111 = 1~6.5 cts/Gt:V>. In tho case:. the: m .. -an value; of the rt:con>lrlll."leti c:ncrgio of the pcn.:tr-ating and th.: nonpenc:tr.uing pions wc:n: found to be .:qua! within the C::\p,:rimc:ntal um.-.:rtaintio (a small fraction uf 1•;.1. When Method (I wa, usc:<l.. th.: mc:.10 valuo <liffcrc:cl by -s- •.

M\B ]<v0q^ —N » i M R%—q0 :S'N*S'NR1 q*% ,—N>£%1 S k>01R0$ I—1—q05> } % b Zj, jB

vZq v f08/9E

v ®INE j E *

_h #

Z'- »z-»+±+ XlUCQC 1XFU —_±=Uv/!q- ql+o !/y8 m

%K_j/?~X%= %U-+U[

U +?E± *u! +u 7

C / _ » U o CZ # x x E Y Zv 4Z»d7J♦; V

v- hA?% ±?K/? /7? T 7

0 j K X] ; _ — XX_ j? j ±K° !k K 1 X

BXJ c 4 ' j — Xl K ^ / ± X ? / K W K±]E±±l z ± / /? /? X? ~ K eU ! ~ ± • ] ? K /± 7K X± hJ d 7X 7?+ ± ^ — E ! ; ± K / ± _ /— J »X+X % X^ — ~ ! 1 r k j 1 h ~ > /_ X? j W ~ ? /' j > _U ^ ~ ! nk7CA./XW vh 8-XXJ WQ ] v cm u /Il k j 1

7 ± ; C GGG

Cc Q? h-

%K+K—Xh?d %l/»»

^ aZN , G] h?U XUUo ERX E h ^ Iv !

qP•]ppk]]p"£j’ "p£■*

c j ' T p _ p - pT -k *( K = e~ _ = ^ ^ K /K XX j ? j ±J ° /g Uj1 v

q d AX 4'j ± _ E ~ ? = / ? ] / X = X j ? ± ±; ° X ' K ? > ^ / h— = XhEA! % j ? XU A4 e? J Tz z X ± ^ X ? ^ ? % ± _ ± / ± X X ? J v > X % / /+ ^ _ / Z r k » 1 h ~ > /_ X? j W ~ ? e? K !jX=/= ~ ! - j /' ~ W q v h ^ = X? J x XX E m X ? c h e = k j 1

- j/' ~ W Dv W ~ j = ? ~ / % ±~ W ^ Kj /' j = _ — j ±j =^ /= _ = - j/' ~ W vv v h > j K_^ =j /' j w- _ ? W q x , =jK /X~ ? = ~ ! /' j L^J 8 % J ±_ W j K _ ~ ? — j /j ± ' _ ; j _ WX4 j±j?/ K ~ — % ~ =X/X~ ? * [ ' XK' /±_? = _ /j= X? /~ W X4 j±j? / 2*x _ ? W 2*YUU! ± _ / X~ = h 4 ' j±j !~ ±j * j; j? /' ~ ^ J ' /' j j?j±J° =K_ j ~ ! > ~ /' =jK/X~?= X= W j /j ±— X? j W [ X/' /' j =_— j % _ ±/XK j = Tj jK /±~?= X? /' X= K _=j '* /' j ±j=%~?=j /~ ~ /' j ± % _ ±/XK j = v ' _ W ±~ ? = * — ^ ~ ? = ' ~ ! /' j /[ ~ K _ ~ ±X— j /j ± =jK /X~ ? = — _° 'j W X4 j±j? /h x ? W /' X=

±j =^ /= * _— ~?J ~ /' j ± /' X? J = * X? W X!!j ±j? / ±j = % ~ ? =j !^ ? K /X~ ? = ~ ± % j ? j /±_ /X? J _ ? W ? ~ ? % K ? j / ±_ /X? J % X~?= h v ! /'j w- _ ? W q x , K _ ~ ±X— j /j ± =j K /X~ ? = ' _ W j]_K/° /'j =_— j = /±^ K /^ ±j _ ? W K ~ — % ~ = X / X~ ? * /' j? - j/' ~ W = vv _ ? W vvv [ ~ ^ W 'j K ~ — % j /j ° j * ^ X; _ j? / _?W =' ~ ^ XW j_W /~ /' j =_— j ±j = ^ /= h

4 ' j ±j=^ /= W j =K ±X> jW _ > ~ ; j Kj_±° W j — ~ ? = / ± _ /j /' _ / ^ = X? J - j/' ~ W v /~ =j/ /' j j?j±J° =K_ j ~ ! /' j q x , =jK/X~? X? /±~ W ^ K j = _ W j % j ? W j ? K j ~ ! /' j ±j K~ ? =/±^ K /jW % X~? j?j±J° ~ ? /' j = /_ ± /X? J % ~ X? / ~ ! /' j =' ~ [ j± x = _ — _ //j ± ~ ! !_K/* /' j — _ X? — ~ /X; _ /X~ ? /~ W j; j ~ % - j /' ~ W vvv [_= /~ j X— X? _ /j /' X= j!!jK/h

iG ♦h >UHY*^ Y„YUUY2*;UVGB ~ ± ' _ W ±~ ? ='~[ j±=* /'j _ ; j ±_J j j?j±J° ! ± _ K /X~ ?

K_ ±±Xj W >° ]“♦= _ ? W ~ /' j ± %_±/XK j= W j ; j ~ % X? J j jK /±~ — _J ? j /XK ='~[ j±= Tj hJ hh ABA= X X? K ±j_ =j = _ = _ !^ ? K /X~ ? ~ ! j?j±J° D X h &' ’ 4 ' X= K_^=j= _ ? UY^;UY(Ub =XJ?_ ? ~ ? XX? j_ ±X° !~ ± ' _ W ±~ ? = X? *VV ? ~ ? K ~ — % j ? E =_/X?J K_~ ±X— j /j ±= h 4 ' X= X? /± X? =XK ? ~ ? XX? j _ ±X° _ % % j _ ±= [ 'j? /' j % X~ ? j?j±J° X= ±j K ~ ? = /±^ K /j W ^=X?J /' j K_ X> ±_ /X~ ? K ~ ? = /_ ? / i.oeX !~ ± /' j = XJ ? _ = !±~ — /' j ' _W ±~ ? XK K _ ~ ? — j /j ± =jK/X~?h

4'X= X= ='~[ ? X? BXJh ph [ 'j±j /Xj ±_ /X~ ~ ! /' j ±j K ~ ? =/±^ K /jW j?j±J° _ ? W /' j W j% ~ =X/jW j? j ±J ° X=

■ -KX '^W v n vv ’h - j/'~W - ♦

.p7xh

d >£^ms8k•^’p■kJ k*k]■]D p 3ks 2

B XJ h ph 4 'j — ' ~ ~ ! /' j ± K ~ 7 K X / ± ^ ' K W j ? j ±J ° _ ? W /' j W j % ~ = X /j W j? j ±J ° _ ! j K J X ~ K ~ ! X' j j ? j ±J ° W j % ~ = X /j W >° % ^ X±^ U!K~[ K??UX X K /' j g , B L h^ ! 8 % J ±_ W j K X X ^ ? — K /j ± h 0 ~ ^ X/l _ ± j X X / K ? ! ~ ± /' j /' ±j j K _ X> ± _ / X~ ? — j /' ~ W = X9 U h8 X=X? X — /' j / K / / ± ' j K ^ ±; j U /' ±~ ^ J ' /' j 7 ; — / X _ ± K ± X _ /~ /' j ! ^ _ K ^ K _ X? wu X< 7

mnc


,

1:Jl•

,...,.

:,u

1,u.

(~)

,t,,

;

;

tGin,,., .Nii - '-"" ut, ! .... -::-,d--~.!.'.U -c_......., 11.0.;: .. ~, ~ "-'"'•llJP"'ill 1lplt. u,r;.,f).DiM.I

=· :~;. I ~~"_!___j .c·. ,"1 i.r,,... I

;,;:--1 !l~I~ !~,!:., j ""•- 1~,ua.:\_!

0t_,np-nn:ns.1 nc ,,..~ l 111 ,, ,., ••

Rc:..-.>rNru,1al .:nn;.ry I Ge V •

Fi,_ ~ T~ n:,:un~tn4.~a.f cr..:rn ~tnt'tUnJc-. (Jr r-,:.1l!tucm,: 1.11 .an.I :1&tn-r,..--r.etr:1~1ng ti,1 r1un., "'f 111_1> G..:\', ,..,bt.u:xJ 1.m :be n~,,. ..,r \lc:!!L.J I. 1.:-.et1r s,, ~ 1 ~1 .a -.;t:.. C..:\·

2 E ~

= .. .ii

··- , .. IU>t

'

·-r "' ~· !"lt

:,,u "~ .. ·~· i •\,;'\ I,::_ - ---1 .( ..... , ... " .... , c ..... - ,;.1,,.111 : ,...... .. . ' ... ·- ; \,£_..·• """I; 1 ,• 1

rc-,::,.;a1.nc p,or ..

I ,,

~· .,,;---l ltr.- .,__.,, I

?:'-: '-'.!·_ ... , 0 1 ,-.MJ .... ,:_\.1 .. 11 I i

l"t ....

11)1•

~•-

v.,__, !'lt,'fl. t •It.: .. I

~,.... - !.\~ ..:__l"ll;~ t • ...,.,ir·r.dUII,.,._ I

,-IJ -~ -- -- - - - __ ._ e_._ -- _j a ' 1 J I! '"' :t>

Rc.:on.uu.:t.:J =!!Y \C.C\.)

.. h~ ~ fhc n:a.unstr1a::at ~nrr:y libtn~lMru fur ~1-'""l:•::--#: IJl •nJ ....-~r.1.hrtC 1b1 f'k>ns ul ~ 6 Go,',', "bu,nat -,n ,~ il.ul\ J( \l.:&,.,.J Ill. 11>1:1~ Bm " I ,c., 5 ,~ Ge\'

Mo:thod II <loo not produc.: the sarnc: r~ulls as .\lcthod Ill. bc\.':lusc the EM and HAD s(Ction., of the: Plug L'pgr:idc caforim,:t.:r ha,.: a ddlcrent compmilion. which tran>lalo into ditTc:n:nt t!lh and <!:'mip ratios. Therefore. even though the energy seal&: of both ><.-ction, is detc:nnin.-d with the ~me partidc:s 1dcctrons in this C-.LS<:). the n:,pon.,c: t.:, ,>lhc:r partides f hadron,-. muon,1 of thc: two 1.":1ll1rirnelc:r ,;c:ctions may b,: diff.:n:nt. And thu

135

J~9

r~ults. among othcr things. in diffcn:nt n:spu~ functions for pcnctr:iting and nonpcnctr.iung piulb. If the EM and HAD caforimc:tc:r ~-lion" had exactly th.: same structure and .:omposuiun. then :0-1.:th<Xb II and Ill would b,: cumpl.:tdy ~w~alent and ilio.dd k·.id to the= n:sults.

The roulb J.-s..,ibcd abo\e d.:-.irly d..."Inolbtr.itc: that \bin~ Mcthod I to >et th,: ,:nc:rgy scale .:,f the H:\D s..-cuon iruruducc:s a depend.:ni.--.: of thc: r•"\.·oru.truct,'1.1 pi,rn cnc:rg~ on thc: starting ['<'int .:,f the ,bower A~ a matti.:r of fa.:t. th.: m~un rnoti\atrnn to J,:\d,,p \kthod Ill "'a., to dimin;1tc: thi, cllo:ct.

5.1.:. Siqrw/ nunlin.·,,rity· For hadron 1hu\,ers. the a\·,:r.1;;.: o:ner;;~ fr.11.-ii,rn

carric-d b~ :f·, and uthi.:r partidi.:, di.:, cl,,pin;; ck.-ctron1agn~hc ,111,".:r~ h:.g .. 11·,1 i1u.,-r.:a.~ a.., ;,1

funcuon c•f energy [ 1.91 Th,, .::111-.~ an mrr111.<1c

,ignaJ nunlinc-anty for hai.lwru in "" nun.:ump.:11--alln~ ..:alonm.:ter... Tl11~ intrin.,ic nonlin,:aril~ appears \\ hen th,: pion i.:ni.:rl?) is r,-co11.,tru.:1c:d u,111;; th,: 1.-;:Ji!,rativn .:011:>tanl Bm f,,r the ..i;;na!:, from the hadrunic calonmetcr ... -cuon.

This 1,; ,hu~ n in Fi!_!. 7. \\ hc:rc: th:: ralto ,,f the reconsrru.:rc:d energy and the depo,ue<! c:ncq,•y 1s

I If

.. .t : . ~k,huJ I

1: M,-,,,_,.i II Mr1hnl Ill :-

.,/

i .,-< t

<l''t

.,,..,,,,..< - _.,.,.,.-- ~ I\ ..

J ~ .. ; !.

o.~f , ..•.. -~ •· .-··

-.- ,..'- ---

~J ~ Ill -~' IUJ .~ .. ,

Dcp<r,irro Cll<.'f'~'J' , Gc1.·,

F,,. 1. The,.,..,"' th,: r,:u,ru.rn;.;ral ,-r.r:rgy .ru1 :lie Jq,<1>1tal c:tl.O\~ ~ .1 !" La:C:JtJC uf t..":t: cncr::!- JcposucJ hy pwns ~t:uwt..TU:lf. u, t~..: CDF P!u, L'pgrJJr c,!.,nm::a. Rouit, '"'I""":·.,, :he t.~ -.-..a.Jt!,uti-,n m..1!:u,.b Ju...lb.•11:,J u1. :hi: rcu fhl: ~un-o thr-,u;:l:. th.: ru,nt> ,,~ :la to the riur.1011 ut E4l ,-1

a:B }E>0<S —] qN [ WR5<—q0 :*<N0_S—^N1 NS $ dN]aqd1 S k>6R5] I—<5R0%< } }MZ Zf W W}[*EgW

% ~ //j W _ = _ !^ ? K /X~ ? ~ ! /' j j?j±J° W j % ~ = X/jW >° % X~ ? = =' ~ [ j ±X? J X? /' j K _ ~ ±X— j /j ± h B ~ ± _ X? j_ ± K _ ~ ±X— j /j ± * /' X= ±_ /X~ [ ~ ^ W ' _ ; j /~ >j j? j±J ° X? W j % j ? W j? /h 4 ' j W j % ~ = X/j W j?j±J° X= kYb[6 L ! X ~ X h [ ' j±j ! X _ / * X= /' j _ ; j ±_ J j j?j±J° /' _ / _ % X~ ? = T% j ? j /±_ /X? J _ ? W ? ~ ? % j ? j X±_ /X? J ' j_9 ~ ^ / /' j >^K9 ~ ! /' j K _ ~ ±X— j /j ± h 4 ' X= j_9 _J j j?j±J° [_= j = /X— _ /j W ~ ? /'j >_=X= ~ ! /' j 6 x m W _ /_ Dt ’* X? /'j =_— j [ _° _ = [ _= W ~ ? j !~ ± % j ? j /±_ /X? J % X~ ? = X? Z jK/X~? u ha h vh

v? /' j !~ ~ [ X? J * [j [X * ^ _ ? /X!° /' j ' _ W ±~ ? XK [J?_ ? ~ ^ X?j hX±X° Tx4.' _ = /' j ±j _ /X; j K' _ ? J j X? /' j K _ ~ ± X— j /j ± ±j =% ~ ? =j > j /[ jj? m s _? W mss k j1e

c£ FTmss' Fmms' E v T-

[ 'j±j F ’ m s s l X= /' j K _ ~ ± X— j /j ± ±j =% ~ ? =j TXhjh /' j _; j±_J j = XJ ? _ %j± k j1 h X? _ ±> X/±_ ±° ^ ? X/= ’ !~ ± m8s k j1 % X~ ? = _ ? W i. Tms' /' j ±j =% ~ ? =j /~ ms k j1 % X~?= h y _=jW ~ ? /' X= W j !X? X/X~ ? * /' j X? /± X? =XK ? ~ ? X? j _ ? /° ~ ! /' j g , B L ^J 8 % J ±_ W j K _ ~ ±X— j /j ± [ _= !~ ^ ? W /~ >j 4 hZ A1

v! [j ^ =jW /' j K _ X> ±_ /X~ ? K ~ ? = /_ ? /= !±~— - j/' ~ W v /~ ±j K ~ ? = /±^ K / /' j % X~ ? j?j±J° * /' j ? _ V*;42; ? ~ ? ' ? j _ ± X° [ _= ~ > =j ±; jW e m m h m R ~;j± /'j j?j±J° ±_ ? J j !±~— ms /~ mss k j1 h 4 X?= K _? >j ^ ? W j ±= /~ ~ W !±~ — /' j !_K / /' _ / _= /' j j?j±J° ~ ! /'j % X~ ? =' ~ [ j± X? K ±j_=j=* — ~ ±j _ ? W — ~ ±j j?j±J° X= W j % ~ = X/jW X? /' j ' _ W ±~ ? XK =jK /X~ ? ~ ! /'j K _ ~ ±X— j /j ± h v? - j /' ~ W vh /' j = XJ?_= !±~— /'X= K _ ~ ± X— j /j ± =jK /X~? _ ±j N > ~ ~ = /j W N [ X/' ±j=%jK/ /~ /' j = XJ?_= !±~— /' j w - K _ ~ ±X— j /j ± =jK/X~? h

B XJ h p = ' ~ [ = /' j ±_ / X~ ~ ! /' j ±j K ~ ? = /±^ K /jW j?j±J° _ ? W /' j W j % ~ = X/jW j?j±J° _ = _ !^ ? K /X~ ? ~ ! /'j _ / /j ± !~ ± _ X /' ±jj W X!!j ±j? / K _ X> ±_ /X~ ? — j /' ~ W = h w _K' W _ /_ % ~ X? / ±j % ±j =j? /= /' j — j _ ? ;_ ^j ~ ! /' j W X= /± X> ^ /X~ ? ~ ! k ' Tw * h Tc''h [ ' j ±j _ % X~ ? = h % j ? j /±_ /X? J _ ? W ? ~ ? % j ? K /±_ /X? J h '_;j >jj? /_9 j? X? /~ _ K K ~ ^ ? /h w _K' W _ /_ =j/ ^ _ = X/ [ X/' /' j !^ ? K /X~ ?

C q±KE ? ' T©'

4 _ > j a X= /= /' j ;_ ^j= ~ ! /' j % _ ±_ — j /j ±= — _ ? W —5 !~ ± /' j W X! !j ±j ? / K _ X> ±_ /X~ ? — j /' ~ W = * _= [j _= —5*—UW [ ' XK' X= _ — j _ =^ ±j ~ ! /' j = XJ ? _ ? ~ ? X? j _ ±E

4 EX> K o

1 X X^ j = ~ ! ♦W ± % _ ± _ — j /j ± = 1v _ ? W Z E* T X~ ±~ /' j ' X ~ ! /' j K ± % j ? — j ? )_X W _ /_ / ^ w*h .p' [ ' XK ' 8 K = K ? > _ v' j ' _ W ± ~ ? XK ^ J ? _ X ? ~ K ' ? j _ ? /° h !~ ± j _ K ' ~ ! e' j /' ±j j K _ X> ± _ / X~ ? ?_j/'K-/= X /K = j ? ' j X/ X? /' j j_I

g 7 X X > ± _ /^ ± _ U h

- ± / ' ~ z m m'sum Al s eu u

vw s j ='~[ = /' _ / /' X= ? ~ ? X? j _ ±X/; X= A u Xz A* _ ±J j ± [ 'j? - j/' ~ W v X= ^=jW _= K ~ — % _ ±j W /~ - j /' ~ W mmm

x ph v„Y(2H’2Yb2( aY; [2^^

v? — _?° — ~Wj±? % _ ±/XK j %'°=XK= j = % j ? — j ? = h /'j W j /jK /X~ ? ~ ! 7j /= _ ? W _ % ±~ % j ± — j _ =^ ±j — j ? / ~ ! /' j X± j?j±JXj= X= ~ ! % ±X— _±° K~?Kj ±? h 4 ' j ±j !~ ±j * [j _ =~ = /^ W XjW /'j j4jK/= ~ ! /' j W X!!j ±j? / K _ X A± X— j j ± K _ X> ±_ /X~ ? — j/'~W= ~? /' j ±j =% ~ ? =j /~ 7j /= h 8 ? !~ ±/^ ? _ /j ° * ? _ /^ ±j W ~ j = ? ~ / % ±~ ; XW j /j=/ > j _— = [ X/' 7j /= ~ ! %±jKX=j° 9 ? ~ [ ? j?j±JXj= _ ? W h /' j ±j E!~ ±jh [ j '_W ~ ±j° ~? - ~ ? /j g _±~ = X— ^ _ /X~ ? = !~ ± /' X= %^±%~=jh

6 j ^=jW _ - ~ ? /j g _ ± ~ = X— ^ _ /X~ ? % ±~ J ±_ — /' _ / [ _= %±j;X~^=° W j ; j ~ % jW _= % _ ± / ~ ! K _ ~ ± XE— j /j ± 0 x , =/^WXj= X? /'j K ~ ? /j ] / ~ ! /' j ZZg ) q g Dms’h 4 ' j X? /j? / [ _= /~ = X— ^ _ /j /'j ±j =% ~ ? =j ~ ! /'j K _ ~ ±X— j /j ± /~ 7j /= — _ 9 X? J — _] X— ^ — ^=j ~ ! j] % j ± X— j ? /_ K_ ~ ±X— j /j ± = XJ?_ W X= /±X> ^ /X~ ? N * /~ X? W X; XW ^ _ %_±/XKj= ~ ! 9 ? ~ [ ? j?j±J° h v? /' X= _ % % ±~ _ K ' * _ 7j / X= /±j _ /jW _ = _ K~ jK/X~? ~ ! ;_±° X?J ? ^ — > j ± ~ ! %_±/XK j=* j_K' [ X/' _ ; _ ±° X? J j? j ±J ° _ ? W _ ;_±° X?J K'_±Jjh 4 ' j j?j±J° ~ ! j _ K ' 7j / % _ ±/XK j X= =jjK/jW ±_ ? W ~ — ° _ KK ~ ±W X? J /~ _ !±_ J — j ? /_ /X~ ? !^? K /X~ ?

Tv E ±!"lTE■' e T+ E v!E TZ'

[ 'XK' [ j Wj=K±X>j= _ ; _±Xj /° ~ ! j] % j±X— j? /_ W _ /_ =j /= Dv ’ h q j±jh \■oa W j ? ~ /j = /'j % ±~ > _ > XX/° /' _ / _ 7j / !±_ J — j ? / [X j? W ^ % [ X/' _ !±_K /X~ ? o ~ ! /' j 7j / j? j±J ° * _ ? W X X= _ % _ ±_ — j /j ± h B ±_ J — j ? /_ /X~ ? !^ ? K /X~ ? = — j_=^ ±jW X? /' j g , B j?j±J° ±_ ? J j !_ ; ~ ± _ ; _ ^ j a f r * [ 'XK' [ j /' j ±j !~ ±j ^=jW X? ~ ^ ±

mnr


l'JO 1/ . • {J,,,.,. d .,J I .Vwkur /n,"-""IJ .,,.J .1/~ritu.l.r u, Ph_>11e1 &,cur,-1, .{ .J.'r r :co:, J:ll-./<15

plollc:d as :i function of the encr~ dc:positcJ by pions showering in the calorimeter. For a lin.::u alorimc:ter, this rJtio would ha~e lo be energy iruJCJ"."lldenL The deposu.cd .:nc:rgy i) Etium -E1cu. where: £al is the :i ,·c:rJgr c:neri,,y that all pions (penetr:iting :ind nonpenetr:iting:_1 leak out the bad. of the calorimc:ter. rnis lc:-.il.Jgc: c:nc:rgy w:is .:sumated on the: b:ui_, of the WA I dau [i-J. in the ,.;11111: way a.s was Jone for pcnc:1r.1ting pion, in S..'l.1ion -L~. l-

ln th..: folluwmg. 1,1,,: will <1uantif~ the hadrunic ,1gnal nonlinc:;1ri1~ 1.lRJ .1., the rdali\"e chang,: in the .:alonmcter n:spon.....: bc:twc:cn IO and 100 Ge\":

R(IINIJ :lR =--- 1111

R(IOI

1,1,here RI If.IOI L\ 1he c-.1l,mm.:1er n:spuns.: 1i.c. the: '" er.ig,: signal r,<:r Ge\,·. in arb11rar~ unit, I for 100 GeV piuns and R( 1111 the r • ..,pun...: tu IU Ge\' p1ons. lla,cJ on 1!11, Jc:tinitu>n. ihe m1rin~11: n,,nlinc:-.int:, ,,f the CDF Plug L'pgr.ide .-:.tlorimc:lc:r ,~a.s found 10 be ;_~· •

lf \\C: u.,c:d th,: .:alihration .:11nstanb from MethoJ I 10 rL'l:<>n,1ruc1 the pion c:111:rgy. then a l.ir.J~r nonlinr:.1/il;, wa., obs..:r,.-d; 11. l •;. uH:r the energ)' r.1n1,-.: from to 10 IOO GeV. Tlui .:an be understvod from the f.u:1 that .u the en.-rgy of the: pion shower IRL,c:asc:s. more :ind more energy 1s Jeposued in the hadroni.: s..-.:uon of the calornneter. In '.\lc:tb,,J I. the signal.; fr<>m tlus calonmeter ~-ctiun are "booML-d" 1,1,11h n_-,,pccc 1<1 th.: ,1gnab frum th.: EM cal.>nmcter Sc:\.'tton.

Fig. 7 ,huw~ the ratio of the r,:con)lruck-d enc:r1,•y and the deposited c:nergy as a function of the latter for all thr.-c different L"alihrauun mc:thods. Ea.:h Jala point rq,n:sc:nis the me-.in value of the Jistribution of Ero..,,. (Eq. 151). where :ti! pions. pc:ne1r.11ing and nunpcn.:tratmg. ha\e heen taken into account. Each data s.:t was lit with th.: fun\:tion

< £,._.,,., ) '· k l E = ..-:, - ! n Jc_,. ~ .... (ii

Table~ lists the \aluc:s of the par.imeters k1 anJ k! for the difTen:nt calibration methods. a.s wdl as k!/k,. which i.\ a measure of the: signal nonlinc::ir-

136

T •blc, ! ,·.iucs af :!:,: II= ,, '1"'1 t,. ::om th< :It -,r tl:.c ap,:nmcnul .!.l.l tu E.f. 171 wluch ~be, th&: t:.-aJrom<: .ai;::.,J noclm~Mtty. for caa:!1 of ~ thri:i: c!il,r;stit..~ mt't!iuds Jc:..nhal m t.!:c ta!

C•ub1:11JOn t, k, k, :i.,

Mct!loJ I 1J !'-' 1)11,:1 IJ 0:-U \kc!i.,J ll 0 •4 OU}.1 0.1-!',le,~) Ill 0 ·= o u;., O_t}_lM'/

it). The I.Ihle shows that this n,,nl111c:ari1y 1s - -111', !ar;;i:r "hen M.:1i1<t<l I i~ IL"--.! a~ .:or.ipared 10 '.\lc:1h,1,l II I

5 .'. (~ms.-q11r·11.-.-.i /or Jct~

In man~ mudc:rn par11d.: ph~\ics e,p,:-nm<.-nh. the: ,J.:1 .. -ction of Jets and .1 rn>p..:r r.1.:-cL,un:mc:r.l of their c:nc:rg1,._ h of pm:ury .:on.:em. T:1erc:forc:. 1\·.:

abu ,tudi.-J th~ cffc-.:1> c•f the diffcrtnl .-.il,•rinu:h:r •.ilihr.11iun m.:thuJs un th.: r,:)pun-e tu j.:t.. L'nfortunatdy. rutur.: does not pro\id.: 1.:,1 beams \llith j.:h uf prc:\:isc:ly lm,11\n energies and. thc:refore. 1,1,.: had to rd) on '.\l,rnte Carlo ,,muuu,ins for thi.:> purpt,-i;: .

W.: u.\Cd :1 ~"1111c: C:irl,1 -imulatwn program that w:.1> pre\i.,u,ly dc,dllf>.:<l :1> p:.lrt of .:alurimeter R.'1:0 nuJi • .., m the c:on1c:.,1 oi the SSC -L HC [IOI. The: intent \\:.I.', 10 simulate: the r.:-;puns.: uf the L-all•rimel.:r tu jc:b 1naling ma.,imum us.: uf c:,;,,:nmc:nt;:! c-.i.!orimc:le: -;ii;nal di$:r:hi::1cn-. to

inJi~1<lual partido of known energy. In this appruacil.. a Jet is lre-.11c:d .u J <.-olla:1iun of \·ar:, in;; number of panid.-s. each wuh a var:,·ing c:nergy and a varying charge:. The c:nerg} uf c:;u;h jel particle is sc:k-ctc:d randomly according 10 J

fragmentation fum;tion

(( - ;f' Dc:1 -_, (2 - IJ -.- (MJ

1,1,hich wdl J.:scribes a ~:iri.:ty of <=-'p.:rimental Jala s.:ls [ 11 J. Hen:. /)(:) Jenolo the probab1li1y that a jc:t fragmc:nl will c:nd up Y.ith a fraction : of the: jet c:nc:rin. and 1 is a par.1mcter. Fr.11,'ltlc:ntation functioR) mc:-~urc:d in th.: CDF c:nerg:. r.i.ngc fa\or a \·aluc 2 = 6, which we therefore usc:d in our

dB BN<9±^? N ] qp [ E1Ûx7± : <R N0 S R * R _— X ,—N>£%' S k>60$pN I—1—£05> hu sWH © jQEVj h .t. EzQz S

= X— ^ _ /X~ ? = h 4 'j K ' _ ±J j ~ ! j _K ' 7j / ! ±_ J — j ? [ _= K ' ~ =j ? ±_?W~— ° =~ /' _ / Y ~ ! /' j /X— j /' j ! ± _ J — j ? / [ _= _ X/s _ — X U ~ ! /'j /X— j X/ [ _= _ K ' _ ±J j W % X~ ? h B ~ ± _ 7j / ~ ! j?j±J° [ j ±_? W ~ — ° % _ j W Y % _ ±/XK j = !±~— /'j W X= /± X> ^ /X~ ? Wj=K±X>jW >° ! ± _ J E— j ? /_ / X~ ? !^ ? K /X~ ? TZ X = ^ K ' /' _ / k» # "Uh[ ' j ±j kW X? W XK_ /j= /'j j? j ±J ° ~ ! /'j X/' ! ±_ J — j ? /h B ~ ± j_K ' 7j / !±_J — j? /* [ j ^ =jW /' j — j_ =^ ±jW = XJ ? _ W X= / ± X> ^ / X~ ? ~ ± /j =/> j_— % X~ ? = ~ ± j jK /±~ ? = ~ ! /' j ? j _ ±j = X j?j±J° X? ~ ±W j ± /~ W j /j ±— X? j [ ' _ / /' j K _ ~ ± X— j /j ± =XJ?_ [ ~ ^ W ' _ ; j >jj? ' _ W /' _ / ! ±_ J — j ? / _K/^_° W j % ~ = X/jW X/= j?j±J° " 7 X? /' j K _ ~ ± X— j /j ±

B ~ ± j _ K ' 7j / !±_J — j ? [ X/' j?j±J° k» [ j ±_ ? W ~ — ° %^ jW _? )- =XJ ? _* = ANm* _ ? W _ q x , = XJ ? _ * _mUNm* !±~— /'j K ~ ±±j =% ~ ? W X? J =XJ ? _ W X= E/ ± X> ^ / X~ ? = !~ ± _ /j =/> j_— ±^ ? ~ ! j jK/±~?= T X ! /' j ! ±_ J — j ? / [ _= ? j^ /±_ ' ~ ± % X~ ? = X! T'j ! ± _ J — j ? / [ _= K ' _ ±J j W ' [ '~=j j? j±J ° [ _= K ~=j=/ /~ /' j j?j±J° K _ ±± Xj W >° /'j 7j / ! ±_J — j? /h B ~ ± X? = /_ ? K j * !~ ± _ vW k j1 K' _±J jW 7j / ! ±_J — j? h [j ^ =jW /' j j ] % j ± X— j ? /_ = XJ?_ W X= /± X> ^ /X~ ? = !~ ± _ ? Zh r k j 1 % X~ ? /j = /> j_ — ±^ ? !~ ± /' _ / % ^ ±% ~ =j h 4 ' X= 7j / ! ± _ J — j ? / [ _= /'j? _ // ± X> ^ /j W _ ? w- =XJ?_ E /hvs iZ hr + 7Ae— _ ? W _ q x , = XJ ? _ c. & E m m s i t hr 'nY h ±j =% jK /X; j ° h B ~ ± _ ms k j 1 ? j ^ /±_ !±_J — j? /* /' j = _ — j % ±~ K j W ^ ±j [ ~^W >j !~ ~ [ jW * > ^ / /' j = XJ ? _ = [ ~ ^ W >j /_ 9 j ? !±~— _ ? j j K /±~ ? ±^? ±_ /' j ± /' _ ? _ % X~ ? ±^ ? h

4 ' X= % ±~ Kj == [_= ±j % j _ /j W !~ ± j_K' ~ ! /' j Y ! ± _ J — j ? /= /' _ / — _Wj ^ % /' j 7j / ~ ! j?j±J° k* W 4 ' j j ? j ±J ° /' j K_ ~ ±X— j /j ± [ ~ ^ W ' _;j ±j K ~ ? = /±^ K /jW ! ~ ± /X? = % _ ± / XK ^ _ ± 7j / /'j? X h = X— %°

rg. [ H !^^?7 Tb '

[ ' j ±j /' j W j !X? X/X~ ? ~ ! /' j K _ X> ±_ /X~ ? K ~ ? = /_ ? /= hm

_ ? W T X= /' j =_— j _ = >j!~±j hB XJ h 5 =? ~ [ = /'j ±j =% ~ ? =j ~ ! /'j K _ ~ ±X— j /j ± /~

7j /= _ = _ !^ ? K /X~ ? ~ ! j ? j±J ° !~ ± /' j /' ±jj W X! !j ±j ? / K _ X> ±_ / X~ ? — j /' ~ W = W X=K^ ==jW X? /' j /j]/h B ~ ± j _K ' % ~ X? / h m s s s s 7j /= [ j±j J j ? j ±_ /j W _ ? W /' j K _ ~ ± X E— j /j ± = XJ ? _ [ _= K_ K^ _ /j W _ = W j =j ? > jW _ > ~ ; j h 4 ' j % ~ X? /= X? B XJ h h ±j % ±j =j? / /' j _;j±_Jj ;_ ^ j = ~ ! /' j m s s s s = XJ?_= _ K K ^ — ^ _ /j W /' X= [ _°h ? ~ ±— _ EX\jW /~ /' j 7j / j?j±J°

■ - j > ~ XX v E h- K/Z ^ v I © - ±/— 8 vvv 7

nq~K5

Tz

)k■ k*k]~D S3ks p

/ X J = ! ^ ± i; j ? j ±J ° ±j=±»XeXlj ; X±j g , 'E L ^ J ) A%j±=Q j

j 7 ~ ? — j / j ± 7 = / ~ ^ ? z [ X/' /' j C8 U ? K g _ ± ~ % ± ~ J ± _ — z K ± j ? > K / X — /' j /j ] / h , Xj j / X ± h j = / ' ± ~ ^ J ' e' j % ~ ± ? ~ _ ±j v v A e ? j ±^ ? ~ ? — /±h w? X4Xh

4 ' j ? ~ ? X? j _ ± X /° !~ ± 7j /= X= Kj_±° = — _ j ± /'_? !~ ± = X?J j % X~ ? = TKh!h B XJh p'h 4 'X= X= W ^ j T~ /[~ !_K/~ ±=e

mh L _ ± / ~ ! /' j 7j / = XJ?_* ~? _; j±_J j ~ ? j E/' X±W * K~ — j= ! ±~ — % ' ~ /~ ? = [ 'XK' W j ; j ~ % j jK /±~ E— _ J ? j /XK =' ~ [ j±= h 4 ' j K _ ~ ±X— j /j ± X= X? j _ ± !~± /' _ / K ~ — % ~ ? j ? / ~ ! W Xj 7j / = XJ?_h 4 ' j ?~?E X? j_ ±X/° _ !!j K /= ~? ° T'j ±j— _X? X? J % ~ ± / X~ ? ~ ! /' j 7j / !±_J — j ? /= h

ah 4 ' j ? ~ ? X? j _ ± X ° X= ? ~ / W j /j ±— X? jW >° /' j 7j / j?j±J° X/=j ! * > ^ / >° /' j „b2;*H2 2Y2;4G „3 x2 [2^ 3;6[62Y^(h Z X?Kj /' j — ^/X% XKX/° X? K ±j _ =j = [ X/' j? j ±J ° * /' X= _ ; j ±_J j j?j±J° ~ ! /' j !±_J — j? /= ±X=j= — ^ K ' — ~ ±j =~[° /' _? /' j 7 j / j?j±J° X/=j!h

v? =% X/j ~ ! /' X= h B XJh IU j] ' X> X/= K ' _ ±_ K /j ± X= /XK = /' _ / _ ± j ; j ±° = X— X_ ± /~ /' ~ =j ~> =j±; jW !~ ± =X?Jj % X~?=h v? % _ ± /XK ^ _ ± * /' j =~%j ~ ! /' j K ^ ±; j !~ ± - j /' ~ W v v v X= =~ — j [ ' _ / =— _j ± /' _ ? /' j = ~ % j ~ ! /'j K ^ ±; j ! ~ ± - j /' ~ W vh 4 ' X= X? W XK_ /j= /' _ / /'j ? ~ ? X? j _ ± X/° j !!jK /= W j =K ±X> jW X? Z jK /X~ ? c hm ha !~ ± = X?Jj % X~ ? = % ±~ % _ J _ /j X? /~ /'j j? j±J ° — j _ =^ ±j E— j?/= ~ ! 7j /= h

4 ' j /± XJ J j ± > X_ =j= W X=K^==jW X? Z jK /X~ ? c hmhm !~± =X?Jj % X~ ? = _ = ~ ' _; j K j ± /_ X? K ~ ? =j* ^ j? Kj= !~ ± 7j/=h 4 ' j =j _ ± j =% jjW ~ ^ / X? /'j ?j]/ =^ > =j K /X~ ? h

tWRW Ex2 3UY*V 2Y2;U[K ;2b„Y(^;’bÛ„Y

x = K _? > j =jj? !±~ — BXJ h ph /'j ; _ ^ j ~ ! /'j ±j K ~ ? = /±^ K /j W j? j ±J ° W ~ j= ? ~ / j*^_ /' j ; _ ^ j ~ !

mnp


51mulation.s. The charge of c:ach Jet fr:igmenl \\'a!>

cho'lal r.inJomi) ~l that tllf lhc time: lhc fragm,:nt w:u. a :cD and.; of the: time il wa§ a ckug.:d pion. For a jc:t of cn.:r~ £"". we randomly pulled n particles from the di;1rihuuon dcscrib..-d by fr.1gmcntation functilln ISi ,uch that £_"' = 1::'.a. 1 £ .. wh.:re £, indrc:11 .. -s the: energy of the ilh fragment. For c-ach jct fra~mcnt. we ic,cJ the mc-.1.,urcJ sii,mal dis1nbullon for t .. -sthcam pu>ns or ckctrons of the narcs• energy m order to Jc:tcrmine what the: ,-:ilorimc:tcr -ignal would ha\"e bec:n had that fragment actual!) dcpo,it.:J rts energy £, in the c;ilorimc:ter

for each jct fragment w11h cn,-rgy E,. ,, c: randoml) pulled an E!\.I signal. r"', and a t-1.-\D ,ai;naJ. _rWd. from th,: ~~•rropondini; signal di.s--1r1buti,,n\ for a t .. ..,tt>.:am run of c:lc:ctrons (if the fragmc:nt wa., ncutrall or pmn~ I if the: fragrm:nt w a:. cbargcd I "ho:..: c:ncrg) wa, do><.-,,t to thc c:ncrgy ,arri.:J h~ !he: jct fra;;mc:nt. For m,tan .. i:. for a 10 Gc\' chargc:Li jct fragmc:nt. wc us..-tl thc c'lp.:nmcnl.ll ,i;;nal dr,trihuli,•n. f,,r an ~-t. Gc:V pion tcstbc;un run for that purpose:. Thi> ;c:t fragment was thcn aunhut.:il an E:1.1 ,ag.nal ,\":"' 0 •

r_ lOi S.6).1.:m and a HAD ,i,mal ~ = I 10:~.61i""'. r.:sr,.-cti,c:ly. F,,r a JO Ge:\' nc:utral fragrn.:nt. the >.1t:1.: pr0<.i:dwc: would be followed. bul the: si!!fial,, "ould t'I<! taken fr,>rn an dc:ctron run rather than a pion run.

Thi\ procr:s.,; wa, repc:-ated for ea.:h of the n fra~.:nb that made: up the: Jct of c:nc:rl_[~ Ee,.. The cnc:rgy the caforimc:tc:r would ha\c: reconstructed for Ulb parta.:ul.:r JCt rhcr. 1~ ~:mrly

~r~ s;--il £'°'"" = ;, ·------7:-;'l --1 Buun,

(9)

whc:rc thc: dc:linirion of the i:a!ibration constant.,, A 30d B is the .arnc as hcfore.

Fig. ~ ,how~ th.: ropon:.c of th.: ~·:ilorirn .. -tc:r lll

jets as 3 function of ::n.:rgy for the: three diff.:rent calibration mc:thods di,,cu,,.-c:<l in the: rc:,t. For c:ach point. 10000 jc:ts w.:re generated and the: c:lionmctc:r signal wa~ cakulatcJ as dc,,crihc:d aho\'e. The: pomts in Fig. 8 repn:~t the: a\'erag.! \'::tluL'S of the 10000 ,i~nab a~-cumula1ed the; way. nomialtzcd to 1he je1 cnc:rgy

• ~lc<b.Kl I ~lctl....J II ' Mc-.bud Ill I ---------

ll:i --------------~ If) ~I 11.0

Jet energy 1(j,:V,

:!'JI

hi:. ,c n~r: ~t er.err')' rO('olltl.,t llf :~...: CDf· Ph:1 l'r~.iJ&:, ..:.1:1..,nrr,4"!.:r A founJ \A.1th tth: \hi::tc: C.ulo pn,~r.m1 J\.""nbi..-J Ul 1th= ti:u. rh..: ;.-ur.o th.rlui.~h :!:.: t"-'ln:.i .1.r.: ~ill: ... , ::i-.: ;u.:~t,l,: u: E4 ,~1.

Th.: nonlinearity for Jct., " d...-arly ~mallc:r th.1n for ,ing!.: paoru. (c.f. Fii;. '.'1. T!11, i, Jue: lo l\\11

fa.:to~:

I. Part of the Jc:t ,il_!nal. on J\C:ra;,.'\: onc:-t!Jird. .:0111..-s from piwt.m., whr.:h Jc:\c:l,lp ck-ctn,. ma!,!nctic ,bm\C:~. TI1c: ~-alonmc:h:r i, linc;ir for that compun.:nt ,,r th,: jet 'll!!t1al. T:ae nunIin.:-arit) affc:cL, on!~ th.: rc:rnainmg p,.,ruon of th.: Jc:! fragment-.

.!. Th.: nonlinc:ant:, is not dctc:m1111.:d b) th,: J.:I c:n.:rgy 11>.:lf. bu! by 1hc: ,m:ruq<' <'ll<T!IY of tire Jrt fr,1<1menrs. Sin.:e the multiplicity incr,:as.:s with c:n.:r~'). thi:. a,cragc c:ncri;: ,,r the: fral_!lnc:nb ri"<.'S mu.::h more slowl~ than the jct energy 1udf.

l:1 ~[lite uf thu. Fig. ~ c.dubii,, .:br.u:tcri~tia that .ire ,cry similar to those obscr.cd for sang.I,: pmn.. In par1t1.--ular. the slope of th.: .. -un·.: for Method Ill is somewhat miallc:r than the slope of 1h.: cun·c: for Mc:tho<l I. This indicaics that the: nonlinearity cff,:cts described in Sc:ction 5.1 . .! for single pions propagate: into the energy mc:a.,urc:mc:nl'i of jc:ts.

Th.: trigger hia.so Ji~usscd in S..-cti,m 5.1.1 for smglc paons also hav,: ceruin i:L1ns..-quc:na:s for jets. Thc:sc are ,pelicd out in th.: nc:xt suh,,,.-.;tinn.

JJ. 77rr final ellc'r!)y re.-unstruction

As 1.-an be: set.'11 from Fi~. 7. the ,·:i.l uc of the r..-constructcd ,:nergy do .. -s not c:qual thc valu.: of

cwi }£%' S kv61R1 I—60q05> Bs Aa 8 . a h W W [*tXx

/' j W j % ~ = X /j W j?j±J° * ±j J _ ±W j == ~ ! [ ' XK' — j /' ~ W X= ^ = jW /~ = j / /' j j?j±J° =K_ j=h v? ~ ±W j ± /~ _ ± ± X; j _ / /' j K ~ ± ± j K / ; _ ^ j ~ ! /' j j ? j ±J ° W j % ~ = X/j W >° _ % X~ ? X? /' j K _ ~ ± X— j /j ± * ~ ? j — ^ = / — ^ /X% ° /' j ±j K ~ ? E= /±^ K /j W j ? j ±J ° * !~ ^ ? W _ K K ~ ±W X? J /~ w *h Tc'* >° _ ? j ? j ±J ° EW j % j ? W j ? / K ~ ±±j K /X~ ? !_ K /~ ± * [ 'XK' X= = X— E% ° /' j X? ; j ±= j ~ ! /'j K ^ ±; j = =' ~ [ ? X? > XJ h ph

Z X? K j /' j K ~ ±±jK /X~ ? ! _ K /~ ± X= j?j±J° W j % j ? W j ? /* /' j /X? _ X % X~ ? j?j±J° — ^ = / >j ±j K ~ ? = /±^ K /jW X? _ ? X /j ±_ / X; j [ _° e

' + E X E T i ♦ e * k n v ? " * ( D g g l m m s '

[ X/' k L Ak6MMaW 4 ' j K _ K^ _ /X~ ? K ~ ? ; j±J j= ;j±° ± _ % XW ° _ ? W /°%XK_° ?~ — ~ ±j /' _ ? /' ±j j X /j ± _ / X~ ? = _ ± j ?jjWjW

v ! /' X= % ±~ K j W ^ ±j \ P _ % % Xj W /~ _ =_— % j ~ ! % X~ ? = [ ' XK ' X? K ^ W j = % j ? j /±_ /X? J _ ? W ? ~ ? E% j ? j /±_ /X? J % X~ ? = X? /' j (’62 ±_ /X~ _ = X? /' j =_— % j X X_ [ _= ^ = j W /~ — _ 9 j BXJ p T_ ? W /' j K ~ ±±j K /X~ ? !_ K /~ ±= W j ± X; j W ! ± ~ — /' _ / = _— % j h /' j ? /' X= % ±~ K j W ^ ±j ° Xj W = /' j K ~ ±±j K / j?j±J° !~ ± _ /' ±jj K _ X> ±_ /X~ ? — j /' ~ W = h v! h ~ ? /'j ~ /' j ± ' _ ? W * /' j % ±~ K j W ^ ±j X= _ % % Xj W /~ _ =_— %j [ ' XK XX X?K ^Wj= % j ? j /±_ /X? J _ ? W ? ~ ? E% j ? j /±_ / X? J % X~ ? = X? _ DU*32;2Y^ ±_ / X~ * /' j? X / ±j = ^ /= ’YUK X? /'j K ~ ±±j K / j? j±J ° ;_ ^j= [ ' j? /' j K _ ~ ± X— j /j ± K _ X> ±_ /X~ ? [ _ = K _ ±± Xj W ~ ^ / ~ ? /' j > _ = X= ~ ! - j /' ~ W vvv

4 ' X= X= X^ = /±_ /j W X? 4 _ > j n !~ ± /' j — ~ = / j ] /±j — j K _ = j h Xhjh =j% _ ±_ /j =_— % j= ~ ! % j ? j /±_ ^ ? J _ ? W ? ~ ? % j ? j / ± _ / X? J j; j? /= h 4 ' j /_ > j =' ~ [ = /' _ / - j /' ~ W v j _ W = /~ _ = ° = /j — _ /XK ^ ? W j ±j = /X— _ /X~ ? ~ ! /' j j? j ±J ° ~ ! ? ~ ? % K ? j /±_ /X? J % X~ ? = h [ ' j ±j_= /' j j ? j ±J ° ~ ! % j ? j /±_ /X? J % X~ ? = X= =° =/j— _/XK_° ~ ; j ±Ej = / X— _ /j W h >° _= — ^K' _ = m s R _ / ~[ j?j±J Xj=h

4 ' X= j ! !j K / X= _ =~ X— % ~ ± /_ ? / !~ ± /' j j? j±J ° ± j K ~ ? = / ± ^ K / X~ ? ~ ! 7j /= h x 7j / X= j ==j? /X_ ° _ K ~ j K / X~ ? ~ ! %♦= T!±~— W jK_ ° ' _ ? W ' _ W ±~ ? = * — ~ = /° % X~ ? = h - ~ =/ ~ ! /' j 7 j / ! ±_J — j ? /= _ ±j ;j±° =~!)h [ X/' j ? j ±J Xj = [j > j ~ [ ms k j1 h Xhjh X? /' j j ? j ±J ° ± _ ? J j [ 'j±j /'j j !!jK /= ~ ! = ° = /j — _ /XK j? j±J ° — X= — j _ = ^ ±j — j ? / _= _ ±j =^ / ~ ! X? X= K _ X> ±_ /X~ ? _ ±j _ ±J j = / h y jK _ ^ =j ~ ! /'j j !!j K / W X=K^ ==jW _ > ~ ; j * 7j /= X? [ ' XK ' _ _ ±J j !±_K /X~ ? ~ ! /' j j? j±J ° X= j _ ± ? j W >° ' _ W ± ~ ? XK !±_ J — j ? /= [X* ~ ? _ ; j ±_J j * > j ±j K ~ ? E= / ±^ K /j W [ X/' _ =° =/j— _ /XK_ ° ~ [ j± j ? j±J ° /' _ ? 7 j / = X? [ ' XK ' — ~ = / ~ ! /'j j? j ±J ° X= K _ ± ± Xj W >° i &=h Z ~ ! / * j _ ± ° =' ~ [ j ±X? J ' _ W ±~ ? = _ ±K ~ ! j== K ~ ? =j E* ^ j ? K j ! ~ ± W Xj /~ /_ j? j±J ° ±j K ~ ? = /±^ K /X~ ? ~ ! /' j

4 _ = /j n

4 Xj vX? hX/ j ? j ±J ° ~ ! % ^ l ±= X' ^ [ K ? ? J X? /' j g , ( L ^ ± 8 % J ±_ W j

K X X _ ? — K /j ± h K _ K ^ _ /j W ~ ? /' j > _ = X= ~ ! w _ m msV 0 j_^X♦= _ X; J X;j? !~ ± _ X % X~ ? = K ~ — > X? j W _ ? W ! ~ ± ^ ' ^ ± _ % / K = ~ ! % /~ ±^ /' _ / X X _ ± /j W m s W ^ ; [ j ± X? /' j w - ~ ± q x , EK j Q ~ ? ~ ! D' j j _ ^ ? — j K ±

, j % ~ = X/j W 50€€46 Xk K 1 X

q r k j1 € > j _ — maha k j1 Q > j_ —

Zhr ®

- j /' ~ W mx %^X±hU m m n E s XL j ? j /±_ /X? J ~ n + X' hI

P ~ ? % K ? j /? / X± ; 7 X e E X' X m v U+E©lI

- j /' ~ W vvx %/A!x q m X . ± &lvL K±[ /±^ /X? j q hb Em ' I m a !/ E ~ A

P ~ ? % j ? j /±_ / X? J Q x E +h m m m a E s v

" T8vEm - j /' ~ W v v vx ±^l!/l U /l U »- m a n E X l IL K?j/±_ /X— U 1 Es hm m m n X s mP ~ ± E% j ? j /± _ /? j W r E s m m m n e s X

_ //j ± /° % j ~ ! 7j /= h 4 ' X= % ±~ > j— [ ~ ^ W >j _;~XWjW X! - j/' ~ W vvv [ _= ^=jW /~ X? j ±K _ X> ±_ j /'j w- _ ? W q x , K _ ~ ± X— j /j ± =jK/X~?=h

rh ,j/j±—X?_/X~? ~! /'j K_~±X—j/j±A= 2 x ;_ j

x ? ~ ? K ~ — % j ? =_ /X? J K _ ~ ±X— j /j ±= _ ±j X? /±X?=XEK_° ? ~ ? X? j _ ± !~ ± ' _ W ±~ ? j? j±J ° — j_=^ ±j— j? /=h 4 ' X= X= _ K ~ ? =j * ^ j ? K j ~ ! /'j !_K / /' _ / /'j _;j±_Jj !±_K /X~ ? ~ ! /' j j ? K J ° K_ ±±XjW >° E “ A= % ±~W^KjW X? /'j =' ~ [ j± W j ; j ~ % — j? /h X?K ±j_=j= [ X/'j?j±J°h 4 ' X= j ? j ±J ° W j% j? W j? Kj X= [ j Wj=K±X>jW >°

iN f A N T " A ' A 8'[ 'j±j D+ X = / ' j _; j ±_J j j? j±J ° ? jjW jW !~± /'j % ±~ W ^ K /X~ ? ~ ! ~ ? j % X~? h _ ? W x X= ±j _ /jW /~ /'j _;j±_J j — ^ /X% XK X /° % j ± ? ^ K j _ ± ±j _ K / X~ ? w]%j±XE— j? /_ W _ /_ X? W XK _ /j /' _ / =H # s hp _ ? W mhn k j1 !~ ± X±~ ? _ ? W j _ W * ±j=%jK/X;j° * [ ' Xj x shta JX;j= _ J~~ W W j = K ± X% / X~ ? !~ ± > ~ /' j j— j? /= % ’ h

v ! 2 _ ? W x ± j % ±j = j ? / /' j K _ ~ ± X— j /j ± ±j=%~?=j= /~ j j K /±~ — _ J ? j /XK ='~[ j±= _ ? W /~ /' j ?~?jjKE /±~ — _J ? j /XK K ~ — % ~ ? j ? / ~ ! ' _ W ±~ ? X'~[ j±=h

FG0


.I/ .. w,,., ... "' <1L I .\·u,;1,.,, fn,1f'111M,iu ,,,,J 1frtlt.,J,, 111 PhfJt•·• /k~arch .4 I. ... ':IJl)1, JJI -J95

the uc:posi tc:u energy. rei,-artlli:s.s of w bich method is used to '<l thc: enc:rgy ,-al~. In order to arrive: at the correct \·aluc of tbe c:ner!:,'Y ucpositc:J b:, a pion in the .. -alorimctcr. one must multipl) th.: reconstnK."tc:d c:nc:rgy. found according 10 Eq. t5J. by an enet'k')-dc:pen.ic:nt .:om:cti\Jn factor. which i~ sim;,ly the inv:=rs.: ,lf the: cun.cs ,hown 10 Fig. i.

Sino: the c.,rr.xti,,n fa.:tor i, energy J,:pemfc:nt. the linal pion enc:r~ mu.~l be: n.'COnstructc:d in an itc:r.lli\'c: wa:,:

I 10)

with E ~ < Em.,.d;. Th.:- .:al .. -ulauon con\er:; .. ~ \Cry r.1piJJy .mu 1:,pi..-:dl:, no m,m: than thnx 1tcr:1ti,,n, .ire n .. -.:dc:d.

If llu~ pnx-c:Jurc L, applic:J ro .1 ,amplc: uf pion,; \\ 111.:h 10duJc:s pc:nctralln!_! and nnn-p.:nc:trating pions m the _,,u,r,: r.itw .c, in thc: sampl.: that \\a~ u,,.,,J tu mal..c: Fi:;. ~ t and the: corr<.-..:Uon fa.:tur.. Jeri\,:d fmm thal -.implcl. 1hc:n thi, pn'<:<.-durc :,1.:ld, the .:orr<.-.:1 C:lh:rg)i for all thr<.-.: .:-.1iibr.1:wn mc:1h,1,L\. If. on th.: other hanu. the: pnx<.'llur.: 1s appli,:d tu .1 ,.unpk \\h1d1 indud .. -,, p,:nclratmg and n,,n-pc:nctr.11in,; ;,1110-. in ;1 J1tferen1 r.iun. then 11 rc:,,ult.s 1.mfr 111 lhc corn.-ct .:nc:r~)i \aluc:, \\hc:n the calorimc:ter calibrat1,1n wa, <.,irric:d out ,,n the: bd,i, uf l\lcth,><l Ill.

T:1i, ~ 1llu.~tra1.:d m Ta blc: J for the mo,t i::.,trc:me .. -ax. i.e. ,,,:paratc: ~mp!o of p,:n.:1r.1u11g and nonr,:netr.iung C\ents. The table: sh,"" that !',,1,:thod I h:ad.,, to a ,},tc:matic unuc:r'-"timal1on uf the enc:r!:,.,Y of nonpcnetrating pions. wh,:re:u the: c:nc:rg_:, of p.:n.:trating ;-iuni is ,yo;tc:m.1t1c:1lly o~s:restimatc:d. by as much a\ 10•;, at low energies.

Thi,- c:ffc:ct i~ abo import.dot fur the c:11c:rgy reconstruction of Jets. A jet is cssc:ntially a rollc:cti,,n uf ;··s (from r.l ucxa:,I and hadrun.,. mostly pions. Most of the: jct fragments arc very wfl with enc:rgic:s \\di bc:l,l\\' 10 GeY. i.c:. in the: energy range where tb.: effects of syst.:matic en .. -rgy mismca.,urc:mc:nt .LS a r..-sult of mis...i!ibr,llilln an: largest. l~-.1u;,c of th,: effect Jis.:u~~-d abO\e. Jc:ts in which .1 lar~,: fraction ,,f the: energy i!I t.-:trric:d hy hadronic fragments will. on avcragc:. be: n:con,tructc:u with a syst.:matic:illy lower c:nc:rgy than j.:ts in which m,,,1 of lhe en<!'r<Jy is t.':lrri .. -d by ;·\. S\ift. c:-.1rly shll'Aering hadrons an: of !cs:. conscquctk-c for tl1c: total .:ncrgy reconstruction of the

138

T•:>I..: J The- ti~tJ Ct".cfe!Y u( rt,rt'.:s ,hu.,~nn~ m ti-.c CDf-" P!u!' L'M?r»d.: al~nfflL'tL.,-. caiculJ.11..'1 lln the ~.bbi ..,;- E.-. f lf}). ROW:.:, .a~ gl\Q for .ill pu>[u ,<HTlbir.::d .uiJ ~,,r subumpin uf ?fUt1S tlu[ ir.ar.,_,aJ h> J--..&.l"-ct u1 t~ E.\l .,r tl:\D ~'"!)1111 t.>t. c!-.c ~alunmc:!cr

£._. '-1,~t,..,J I Alt ?t-'r-> P..:~trat1:;.,,:

'""'"'--"KtrJta:-::.r

c._. ,1.,1:uJ II A!l r•L•n., Pe=i.:tr;1!1n;;

'lln{'-nctrJ~l:ltl

£,..., '-k<l:,>tt Ill ·\JI f'll'ft._" r;:r4tr:1::r.:.? ,,,r:r---:1..:rr .tCL1.tZ

5,6

\.b:._{).t

q j :._4).!

., :_ -1) J

•6-:01 'PJ-1)!

"·5 .. "·'

:-1 rt:,, I ,.: -= .J. l ~-b~O.J

·~ l!J_:\) t u :::..o ~ l(i.i ... 1)1

l.!!~O l 1: h -n 1

l.!~-1)1

1: .': ll I 1:: .. i,: 0 l 1: . .1 :0 I

lattc:r t~ pc uf J.:t,,. T!m prubicm ,\uu!J b.: a,oiJ .. 'll 1f '.\.l,:th,>J Ill \\a., us.:J to 1n1c:n..ilihr;i1c: the: E.\I .111J H,\D calorimeter ,,,:.:11011'.

b. Determination or the c:ilurilndcr'" ~.' It •:ilue

All non ... "tlmp,:n.~.llin~ calurimc:tc:rs arc 1nrrin~1-call) nonlinc:-.1r for hdc!rnn c:nc:rgy mc:.1_,urcmc:nL,. This is a coM<:q uc:ncc of the: ta,;:t that the: ,l\c:r.igc f,.11:llon ,,f rho: c:nc:•gy c.im':'l! h~ ,.o·, pr,><lw."l!d in

thc: iliu,\Cr Jevdopmc:nt. 1=, incr,:a,..,-s "uh .:nc:rg:,. Tlus cn.:rgy JcpcnJ::n-.c is ·;..:J! J~ritic:d by

. E)'-' fao = I - (-£.,

I I I)

whcr,: Eu ts the average enc:rgy n<.~OO for the prnducti,,n uf one: pion. anJ k is rd.atc:J lo th.: a\erag.: multiplicity p,:r nuckar re-.1c:11,m hp,:nmcntal uaw indic;1tc: that £,, = O.i anJ 1.3 Gc:V for iron and lead. r<.>5p,:ctivdy. while k 0

- 0.112 givc:s a gooJ Jc:,,cription for b,.,th c!c:rnc:nb ('If.

If e and h n:pn.-s.:nl the: <.-alonm.:tcr rc:sponses to d'-,:tromatmetic ,howcr. and lo the: nond .. -ctrom:i!_!nc:tic • ._.,mponent of hadron ,bowers.

1 }<90q^ N N E < = QR % * q 0 [*1N0RS—*N1 R*<N BbNN9SN1 <* z9QR5h I*S1q€v u }WA iQ Q i E WW[ E z b c

±j =% jK /X; j ° h /'j? /' j ±j = % ~ ? =j /~ _ % X~ ? =' ~ [ j±* j h K _ ? > j [ ±X//j? _=

m+ Ei+IU =~ /' _ / /' j 5nW2 = XJ?_ ± _ / X~ >jK~— j=

;W W ' W x# p*Enm # Dv Ei=_ ©®j j

TXel

Tmn'

4 ' K ±K /♦~ ±j h X! /'j K _ ~ ± X— j /j ± X= X? j_ ± !~ ± /' j Xj Xj K X~ ? ~ ! j j K /±~ — _J ? j /XK ='~[ j±=* X/ K^? ~ ? ° > j X? j _ ± !~ ± % X~?= X! !/* j E m h Xhjh X! /'j K _ ~ ±X— j /j ± X= K~ — % j ? =_ /X? J h

( ? ~ [ X? J /'j j iX ; _ ^ j ~ ! /' j K _ ~ ±X— j /j ±* /' j % X~ ? ? ~ ? X? j_ ±X/° K _? ' j K _ K^ _ /j W X? _ = /±_ XJ ' /E!~ ±[ _ ±W [_° v? /' X= K ~ ? /j = / * [j W K /X? j /' j ? ~ ? X? j _ ±X/° /' ±~ ^ J ' /' j ±j =% ~ ? =j ±_ /X~ ~ m s Tm

_ ? W m s k j1 % X^?=h B XJ h b ='~[ = /' j ±j _ /X~ ? = ' X% > j /[ jj ? /' X= ±_ /X~ _ ? W /' j j ! / ;_^j !~ ± =_— % X? J K _ ~ ± X— j /j ±= >_=jW ~ ? X±~ ? ~ ± j_W _ = _ > = ~ ±> j ± — _ /j ± X_ * ! ~ ± j] _— % j * _ ? X±~ ? K_~ ±X— j /j ± [ X/' 2 !/ E m h r [X j] ' X> X/ _ ?~? X?j_±X/° ~ ! m s R T± j = % ~ ? = j mss ms k j1 E v hQ X

6 j K _ ? ^=j /' j — j _ =^ ±j W ' _ W ±~ ? XK ? ~ ? X? j_ ±X/° /~ j = / X— _ /j /'j jh i/ ; _ ^ j = ~ ! /'j g , B K _ ~ ± XE— j /j ±= h 6 j '_;j /±XjW /~ W ~ /' X= =j%_±_ /j ° !~ ± /' j Tj _W * =K X? /X_ /~ ± w - _ ? W T X ± ~ ? =K X? /X_ /~ ±X q x , =jK /X~ ? = h 4 'j ? ~ ? X? j _ ±X/° ~ ! /' j ' _ W ±~ ? XK K ~ — E% _ ± /— j ? / !~~[ = !±~ — /' j j?j±J° W j% j? W j? Kj ~ ! /' j K _ X> ±_ /X~ ? K ~ ? = /_ ? / T]W [ 'XK' [_= ~ > /_ X? j W !~ ± =' ~ [ j ±= /' _ / W j % ~ = X/j W /' j X± j ? ^ ±j j?j±J° X? /' X= K ~ — % _ ±/— j ? /h v / [ _= !~ ^ ? W /~ >j p h r ] m n N ® T=jj 4 _ > j vh B Xj h u'h B Xj h b X? W XK_ /j = /' _ / /' j _ / /j ±

d ms

v , s c

(/Mh b h 4 ' j ± _ /X~ ~ ! / ' j K _ ~ ± X— j /j ± /~ mss _ ? X

ms k j 1 % X~ K = h zn _ z^ ? K /X~ ? £° / ' j 5’> ; _ ^ j Tma'h w ) ] % j ? — j ? ^

X / X 8 7 ± ; J X; j ? ~ ± T'j X ± ~ ? E ' ^ = ~ q x , ; K W X~ !/ — X _ ? W /' j > X/_K /X w - +»K/(l? >+ ~ / /' j g , B L ^ J 8 % J ± _ W j K _ z ^ ? — K /K ± h

;_ ^j K ~ ± ±j = % ~ ? W = /~ j i! / f mhuu S shst* !~ ± /' j Bj*o = K X? /X_ /~ ± ' _ W ±~ ? XK K _ ~ ± X— j /j ± =jK/X~? h

v? Z K K /X^ ? chmhah [j =' ~ [ j W /X_ / /'j X? /± X? = XK ? ~ ? X? j _ ±X/° !~ ± /' j j ? /X±j K _ ~ ± X— j /j ± TXhjhh w - E q x , =j K /X~ ? = ' [ _= !~ ^ ? W /~ >j p hn S m hm R h Q ? _ ; j ±_J j * /' j j?j±J° ! ±_ K /X~ ? W j% ~ =X/jW >° /' j =' ~ [ j±X? J ' _ W ±~ ? = X? /' j j j K /±~ — _J ? j /XK L > = K X? /X_ /~ ± =jK /X~ ? ;_±XjW > j /[ jj? E m s R _ / ms k j1 _ ? W E n s R _ / mss k j 1 B ±~ — /' X= * ~ ? j K_? j = /X— _ /j /' j ? ~ ? X? j_ ±X/° !~ ± _ ? j ? /X±j K _ ~ ± X— j /j ± [ X/' /'j =_— j L > = K X? /X_ /~ ± = /±^ K /^ ±j _ = /' X= w - =jK /X~ ? /~ >j Zhn S u hr R 4 'X= /±_ ? = _ /j = X? /~ _ ? j !/ ; _ ^ j ~ ! m hu n ] s ha p T=jj BXJh b'h

4 ±_ W X / X~ ? _ ° * /'j j ! / ; _ ^ j X= Wj /j ±— X?jW !±~ — /' j j? j±J ° W j% j? W j? Kj ~ ! — j _ =^ ±j W j ;W = XJ ? _ ±_ /X~ = h 6 j ' _ ; j _ =~ ^=jW /' X= — j /'~W _ = _ ? X? W j % j ? W j ? / [_° /~ K'jK9 ~ ^ ± ±j=^/=h 4 'j j* N =XJ?_ ±_ / X~ = !~ ± /'j X±~ ? = K X? / X_ /~ ± K _ ~ ±X— j /j ± K _? >j W X±jK /° Wj±X;jW >° K ~ — % _ ± X? J /'j ;_^j= !X _ ? W v!XX T=jj Z jK /X~ ? uha'h x = _ — _ //j ± ~ ! !_K /* /' j ±_ /X~ !^ !X U( xK m23UYUÛ„Y /' j 2; W =XJ?_ ±_ /X~ ~ ! /' j ' _ W ±~ ? XK K _ ~ ±X— j /j ± =jK /X~ ? h

BXJ h ms =' ~ [ = /' X= ±_ /X~ _ = _ !^ ? K /X~ ? ~ ! j?j±J°* / ' j K ^ ±; j = X? /' X= !XJ^±j ±j % ±j =j? / /'j j]%jK /jW j?j±J° W j % j ? W j ? K j ~ ! /' j jh = = XJ ? _ ±_ /X~ * !~ ± W X!!j ±j? / K' ~ XK j= ~ ! /'j j A x ; _ ^ j h 4 ' j=j K^±;j= _ ±j /' j J ±_ % ' XK _ j* ^ X; _ j? / ~ ! Bh*=h v ' _?W Tmn'h B ±~ — /' X= = /^ W ° * [ j !~ ^ ? W /' j > j=/ _J ±jj— j? / [ X/' /' j j ] % j ± X— j ? /_ ±j=^ /= !~ ± j ! / f mhnrh [ X/' _ = /_ ? W _ ±W W j ; X_ /X~ ? ~ ! s hsc h Z X? Kj /' X= j] % j±X— j? /_ ±j =^ / X= > _ =j W ~ ? — ~ ±j _ =% j K /= ~ ! /' j j] %j±X— j? /_ W _ /_ * X/ X= =~ — j[ ' _ / — ~ ±j % ±j K X=j /' _ ? /'j ; _ ^ j W j ±X; jW ! ± ~ — /' j ' _ W ±~ ? XK = XJ ? _ ?~? X?j_±X/° _ ~ ? j h q ~ [ j; j ±* > ~ /' ±j =^ /= _ ±j [ X/' X? j ] % j ? E — j? /_ ^ ? K j ± /_ X? ^ j = j* ^ _h v? /' j !~~[ X?J* [j [ X ^=j /' j — ~ ±j %±jK X=j ; _ ^ j Wj ±X;jW !±~ — /' j j?j±J° W j% j? W j ? K j ~ ! /' j j i = = XJ?_ ±_ /X~ = !~ ± /' j X±~ ? * = K X? / X_ /~ ± =jK /X~? ~ ! /' j K_ ~ ±X— j /j ±h

6 j — _° K ~ — % _ ±j /'j j i! / ; _ ^ j = ~ ! /' j g , B L ^J 8 % J ±_ W j K_ ~ ±X— j /j ± [ X/' /' ~ =j ~ ! ~ /' j ± K_ ~ ±X— j /j ±= /' _ / ' _; j /' j =_ — j = /±^ K /^ ±j h 4 ' X= X= W ~ ? j X? B XJ h v v h [ 'XK' =' ~ [ = /' j j ♦!/ ;_ ^j ~ ! =j;j±_ B j = K X? / X _ /~ ± TB XJ h q _ ' _ ? W L> =K X? /X_ E/~ ± TB XJ h X > ' = /±^ K /^ ±j = _ = _ !^ ? K /X~ ? ~ ! /' j =_— %X?J ! ± _ K / X~ ? h a Q ? /' j > ~ //~ — _]X=* /' X=

& 4 ' j »±iX± ; _ ^ j U / ^ % X _ — 7 X? T' XU ! XJ ^ ±j _ ± ? Xj X/XU— 0 j!U Tvn hzm h8 v

mnb


.\I .4ih,uw a .Ji I .\"w:4:ar l11.11n1P1<.-nu unJ .\l,dw.b ut /'/nun k-.acit A 4-r ':oo: · j,!f -j95 J9J

n:,,pa:ti\·c:ly. th~,, the: ropo1u.: to a pion sho,\,:r, ,:, ._"an be wrillc:n a,;

(I.~)

,o that the ::e ~ignal r.lli<> b.:com~

I! l1 - ~ }~a, - [I - ;;,,,1- (I}) t' t'

Thc:rcfon:. if the: .:..t!orimcta i.s linear f,•r rhc: dcrc.:ul,n of .:kctromagncuc sho,,·c:r,;. it ,-an only b,: lin..-.ir for pion:. if /z,.: ~ I. i.c. 1f tbc: .:.i!onmctc:r is cump.!n\atmg.

Knowing thc: e 'I, ,·aluc .,f the c-alonmctc:r. thc pion nonlmc:mty can he calcul;uc:<l m a ,trarghtfurwarJ Wa} In this et•nh:~t. 11,c define the n,mlin.:-.irit~ 1hro11gh 1hc: r.:sr<in..c: rall,> ,,1 IOO and 10 GcV p1un.,. Fii,:_ ') ,hu\h thc: n:la111111sh1p bctwc-cn tlu, r::itio .ind thc: e; Ii ,aluc: for ..ampling 1."alorimctc" ha,cJ l>n iron or l.:-.1J a... .ib,orb.:r matc:naL For c:~1mplc: . .in irnn c::ilonmc:tcr ....-llh <' ·h = 1.6 ,,1!1 c:1.hibit a nunlin.:ant: ,,I 10''.,, tropo!be 100 10 Gc:V ~ I.Ith

We: '-"a.It lL-.C the: ma,,ur.:<l hadwni.: nunhncam: to otim.llc: the: e.-1, valu..-,; of tho: CDF calorimc:ti:n. We: h.ivc tm.-d to J,, tlus ,;,:parat.:!y for the (!i:-.iJ. :w.:inullatort EM mJ tiron s.:mu:l;itur, HAD ..._-ction,;. The: nonlinc::irity of thc: haJr,•nii: compartment fo!lous from the i:nergy dc:p.:ndc:no: of th.: .:-.i.libr.ition .:on.\tanl 8 1• 11.h1..:h was ,,buin .. -d f<>r ,howc:I"> that dc:pu,it .. -d thc:ir c:nure c:ncrb'Y in this compartmc:nt. It w;i.s found Ill be: 7.6-=. I.J~-~ ( ,ex Table: I. Fig. J 1. Fig. '.l in.lic-.110 that th.: l:Utc:r

0.5

-I ./] . /

i i

! '

10 IS ::.0115 111 11

c:/h :.11

fig. 9. Tb: ''""' .. r the Cllonmc!i,r l'C>f"llbO l,J lilll =1 10 Gc:V puJCs . .a:s ~ ?iln.:lloa ,>(Chet! .. /r valac (11!. E.lpa,mi:al.ll J.il.! Jn: l!m:n ,-.,. the ,wn-haw HAD .....:IH>ft tal .u,J :he lc:aJi:,. .... 'tl E;I ><-cthln 111, ,,f ti-..: CDF P!~g Urrraill: _.,llunm.:tc..-.

139

value: corropomb tu c,-"h = I .+i ± O.llS, for th.: Fc:i scintillator hauronic .. -:ilurimc:tc:r 'il!i:tion .

In Sc:i:tion 5.1.~. we sho\\<.-J that th.: mtriru.ic nonline-.iritv fur the: c:ntin: cal<>rimc:tc:r I i.c: .• E!\1 -HAD ...:cti:,nsl was found lo bc i.S±I.I~~- On :m:mge. the: c:nc:rgy fraction dc:positc:d by the: showerinii luurons in the: dc:ctrom.11?nc:1i..: Ph si:intil!at.;, ,ccuun \·aric:d bc:tw,-c:n • - .ur ·., at 10 Gc:V and - JIJ'', at 100 Gc:V. From thb. one: ,:an otimatc the: nllnlinc:-.1.rll} r..,r an c:ntirc: ca!urir.1.c:1.:r with the ..am.: Pb s..-intillatur stru.:tur.: as this E.\I s«Uun 10 be M.J±--1.c.': ... This 1ran,f.uc-, into an"· /z ..-:llu.: of 1.-l) :::O.~i 1,c:c: rig. 9).

T r;1ui tllln:tll \'. the: ,. 'ir \ :LI UC: i, d,:tc:rr.unc:d frl,m th,: ,:n,:rg~· <i,:.,C:n,.knc-c uf m.:-.1.sur.-d t!. :: ,1 ~rt.JI r.tlllK. We: have: also usc:<l thL, mc:thod as an indi:pcnuenl ua~ tu chc.:L our l'l:,ulb. The e. :r ~,gnal ratio~ for lhc: iron ~,nullator <::llonmc:cc:r .-an be tlir,-cth t.li:ri,c:d b\ conwanng the ,a!uc.. 81 .rnd 8 11 r,.c:e S,-cuon --1.~;. ,\,; :i mancr or fa..:t. the: r.itiu 811 · 8 1 o /,1· Jt'/mlllon the t'':: ,1~nal ratio ,,f the hadromc c:i!llflmctcr -.:cuon.

Fig. lO ,ho\\s tlu., r;iu,, a3 a funi:twn uf .:nc:rg~lhc: cunc:s in thh figure rc:pr.:sc:nt the: c:.,pc:ctc:J cn.:rg:, J .. -pc:m.lc:n .. -.: of th.: eir. ~ignal r.uio. for Jilli:rcnt d1oin-:. of the ,· '/1 \-alui:. Thi:s.: .. -uno .irc: th.: graphical c:qua,·aknt of Elj~- I I I I and 1131 . From this ,lulh. \\I! fount.! the: bc:.t agr .. 'ffll.:nl 11.1th the: .:.,pcrim.:nul ~"!>ult.. for e.1h = U6. uith a stand;ml dc:,i.ilion of 0.05. SinL-c 1lus ,::,.p,:rimr:ntal n:~ult L\ ha.>.."ll on mor.: a.,pc:.:1:1 ,,f thc: c:,pc:rimc:ntal data, it i, >001<."\\ hat more: prc:t:i>e than th.: value: J,:riv,:tl from lhc: hat.lrnnic signal nonlin,:arity alone:. Howe,cr. both roult.s ar.: \\ilhin c:xp.:nmc:ntal unccrtainuc:s etjll.ll. In the: following. -.c: will us.: lhe more: prcci>c: value d.:rivcd from the: c:nc:rg) dc:pcndc:ni.:c: l,f the: e,' ~ ,;ig,ul r.ill<>S for the: iron. scmullator !ol."Ction of tile: calurimc:Lt:r .

We may compare: the i:(h "aluo of the: CDF Plug U pgradc: calorimctc:r \\ 1th those of other L-.ilorimc:tc:n that havc: the: same: strui:turc:. Thi> 1s done: in Ffa. 11. which \hows the: e, 'h ,·a!uc: or sc:,·c:r.il F.: ,:_;ntillatl•r (Fig. I !a/ ;inJ Pb-~-intillator (Fig. I lb) structu~-s as a function of the: $alllpling frai:tiun. 2 On the: bottom ;uis. this

;The ~.,-h \·aJua ,JDr{!lyN 1n ttb hgurr ,;.urn.: flltm R...-1·~ ID.~.!~!

Q ° }]90_^ N N Rp [ WR5]N*€0 [* $<0R*NS R R*d , NN>£% X <* k>61<5' I N<NR * > } s}r BjV°.j{

=_— % X? J !±_K /X~ ? X= j] % ±j==jW _ = /' j ; ~ ^ — j ±_ /X~ ~ ! /' j %_==X;j _ ? W _ K /X; j K _ ~ ±X— j /j ± K ~ — % ~ ? j ? /= h £[W v? >~ /' K _=j = * /' j 2*x ±_ /X~ K j _ ± ° WjK±j_=j= [ X/' /'j =_— % X? J !±_K /X~ ? TXhj hh [ X/' X?K±j_=X?J ! / * ' * _ ? W X? /'j K _ =j ~ ! L > = K X? / X _ ~ ± K _ ~ ±X— j /j ±= * K~ — % j ? =_ /X~ ? ' _ = j; j? >jj? _K' Xj; j W * !~ ± _ =_— %X?J !±_K /X~ ? T ! ~ ± — X%=' ~ ! E m c R v £' E u hc ' Dmuzh

4 ' j £[ ;_^j= ~ ! /' j g , B L ^ J 8 % J ±_W j K _ ~ ±X— j /j ± _ ±j mhmn !~ ± /' j j j K /±~ — _J ? j /XK j_W =K X? /X_ /~ ± =jK /X~? _ ? W Z hu. !~ ± /' j ' _ W ±~ ? XK X±~ ? =K X? /X_ /~ ± =jK /X~? h 4 ' j 2 x ;_^j= ~ ! m hu n S s ha p XL > X _? W mhnr - 'h^c TB j X _ ±j X? J ~ ~ W _J ±jj— j? / [ X/' /' j j] % j±X— j? /_ /±j ? W _ % % _ ±j ? / !±~ — BXJ h mm

4 ' j g j ? /±_ g , B K _ ~ ± X— j /j ±= * _ /' ~ ^ J ' K ~ — E% ~ =jW ~ ! /' j =_— j = /±^ K /^ ±j _ = /' j L ^J 8 % J ±_ W j * ' _ ; j ;j±° W X!!j±j? / = _ — % X? J !±_K /X~?=* [ X/' £[ ; _ ^ j= ~ ! shru Tw - h L > X _ ? W ahc Tq x , h Bj'h ±j=%jK /X;j ° h 4 ' j X± 2[x ; _ ^ j = * j]%jK/jW ~ ? /' j > _=X= ~ ! /' j j] % j±X— j? /_ /±j ? W * _ ±j X? W XK _ /j W >° W ~ //j W X?j= X? BXJh mmh 4 ' j ° _ ±j K~?=XWj±_> ° — ~ ±j ? ~ ? K ~ — % j ? =_ /X? J /' _ ? /' j L ^ J 8 % J ±_W j K _ ~ ± XE— j /j ±h 4 ' j±j !~ ±j * /' j K ~ ? =j* ^ j ? Kj= ~ ! ^ = X? J K _ X> ±_ /X~ ? - j/' ~ W v = ' ~ ^ W >j j]%jK/jW /~ >j K ~ ±±j =% ~ ? W X? J ° _ ±J j ± X? /' j =j g j? /±_ K _ ~ ± XE— j/j±= h

ph g ~?K^=X~?=

E v v!/UI G v U

!K?K±7l Z MM S Z

v ^ 4 ' j /] 7; !/— j?^ X »U ® ^ U ? _ X ± _ / X~ _l _ ! ^ = K /_ A/ X ~ ± KKK±J° !~± /'j X ? ± K h = K X j ^ X _ /~ ! =jK/X~? ^ ! /'j g X'( ^W~?±_j/j± 4'j K^±;jU ±j%±j=j?/ /'j j]%jK/jW - ^;^+± eAXU± WXj±j?I ;_^jU ~! =L>B Zjj L—€n !~± Wj/_XUh

v? /' X= % _%j±* [j K ~ — % _ ±j /'±jj W X!!j ±j? / — j /' ~ W = ~ ! =j//X?J /' j ' _ W ±~ ? XK j?j±J° =K_j ~ ! _ ~ ? J X/^ W X? _ ° =jJ— j? /jW K_ ~ ±X— j /j ±h 4'j — j±X/= ~ ! /' j =j — j /' ~ W = ' _ ; j > j j? = /^ W Xj W [ X/' /j = /> j_— W _ /_ !±~ — /'j g , B L ^J 8 % J ±_ W j K_ ~ ±X— j /j ± v/ /^ ±? = ~ ^ / /' _ / ~?j ~ ! /' j TK~— — ~?° ^ =j W X K _ X> ±_ /X~ ? — j/' ~ W = X? /±~ W ^ K j = _ ? ^ — > j ± ~ ! ^ ? W j = X±_> j =XWj j!!jK/=* =^ K' _ = _ ? X? K ±j_=jW ' _ W ±~ ? XK = XJ?_ ? ~ ? X? j _ ±X/° _ ? W T? J J j± > X_=j= ±j =^ /X? J !±~ — /'j !_K/ /' _ / /'j ±j K ~ ? = /±^ K /jW j ? j±J ° W j% j? W = ~? /'j = /_ ± / X? J %~ X? / ~ ! /' j ' _ W ±~ ? ='~[ j±=h 4 ' j=j % ±~ > j — = _ ±j _ W X±j K / K ~ ? =j * ^ j ? Kj ~ ! /'j ? ~ ? K ~ — % K ? =_ X? J ? _ /^ ±j ~ !

=_— % X? J v ? X / X ~ j / ~ ± — X% = A / X

n' vv1 U ms U E X ~U ~ o h

ms vzvUE m x'±Zv m ■ £ ’x/U5c’ X ?XE

vzv r m U©

m ' h & BKi.+KX?/ m uE

3X/E

X E ± / zE

’7nXUgs!L/_Ue E g,Bg—±_ s ]<0

L >i=KX? /

■ g , B g — —

X ■ ’x»X86% A E DyK±_Zq» ’6 U;’

/ X[ * * — X ^ h / ^ E X o o ’/l07 #+BX7Xh mmh 4 ' j ± > ; _ ^ j ~!U U K Cj ± _ B K ;K/_^v) _/~± _ ? W L > [ /? ^ X / ~ ± ^ X ~ ? ± _ K / K ? z X _ !^ ? K /X~ ? ~!U /' j ;_\?%8 ?7X !' /K/( X? / ~ ± ? ^ % = / / ~ %

~ ± /' j ;~ ^— j ± _ / X ~ ~ ! %__MX;j _ ? W _ K /X; j — _ /j ± X_ * 3Um / > ~ //~ — _ ] X_ T v ' h 4 ' j W^M'KW X?j ± K % ? ± K ? / X / ' j K ~ — % K _ ^ / X~ ^ K ~ ? W X / X~ ? ;EXX f v s«

mus


sampling fraction is .:xp=cd as \he .,olumc r.itio of the pas.,ive and acti\"c calorimeter components. R,;. In both .:aso. the ejh r.itio ckarly decre-.lSO with the sampling frac:ion 1i.e .• with 1ncr~":lsing R.i), and in the: ca,.: of Pb,scintillator cal,,rimctc:n. comp.:mation ha., C'en been achic:11c:d. for a sampling frJL:tion 1for mips) ,,f -J.5% j R.i--1.51 [ 1-IJ.

TI1c R. ,·aluc:s of the: CDF Plug Upgr.idc: 1.-alurirn.:kr arc: l. l J for the ekctrumag11c:1ic lc:-.id scintillawr section ;lfld 8.-l7 for the hadronic irons.:mullator ><:\:lion. Tne e_ I, v;iluo of 1.4] :!: 0.~7 1Ph1 and l.36 ::;O.U5 I f'c:_1 ar,: in g,,Cld agr.:.:mo:nt ~ith the: ~lperimc:ntal tn:nJ apparent fr.11:1 Fil,(. 11.

,_i.1~. ---------------

... --e1'1-iT

dl, - " c·'1 .. I' i

1w~· ______________ ___.

:n l:ncr;y 1GcV,

h;:.. Ju Tl:c: i:.,~nmc:r::..1! r- · -~ lt.l~nJl rJ[to .u .1 (u:!l.:~11•0 "f a:trc-'Y tor t!lr irnr...:icu:uHelttJr ~"11'JC of the cu1-· ~nmc:tcr Th~ '-"llt'\o rcpn-:.:nt t!:~ c:..tf.'."\:!cJ ~h.!\11.tf' :"L,t J:Hcr .. -:t! 'i.l;L.a Jc'~-'"· ~ :c:1: f..w -.k:att!.11.

The Central CDF clorimc:tc:rs. although cumpo~ of the same structure as the Plug Upgrade:. have \C!ry Jiffc:rcnl sampling fr.iction.~. with R,1 \·:ilues or O.~ !EM. Pb1 md ~-5 CHAD. Fc:1. n:spa:ti\"c:ly. Their e;"h value:;. C:Xpd"tc:d on the: ba..is of the: c:.,p,:rimental tr.:nd. arc md1cat .. -d b~Jouc=d Imo in I-ii!. 11. Thc:11 ;ire: uinsitlc:rabh more non.:ompc:n.-atini than th~ Plug Upgr.idc ·~-alorimetc:r. Therefore:. the: con;c:quc:ncc:s of u~mg c-.ilibratio11 !'.lc:tbod I should be expcct.:J to be: com:spondingl~ l.-irgcr m these Cc:ntr..1I calonmeters.

7. Cum:lusiurr.

In this pap.:r. \\I! .;,,mpan: ll1re-c: Jitforc:nL m.:th,>d, or ,.:tung the: hadromc .:ner,;y ~-..1lo: of a longitudinally ,egmcnti:d c~1lonmc:1cr. TI1c: mc:rib of the,.: method> h.n.: b,-.:n ,tudied "'ith lc::itb..-am .!at.i fr,m1 1h.: CDf l'lug l."pgradi: ,:;if.,nmetcr It lur~ out that one of the 11:ommonl~ u.-;..-...!1 ,-aiibr.1tion m.:thl>lh mtroJm:c, a number ,,f und,:,;irabk ,idc c:tfocL>. ,m:h a.,, an 1m:rc-a:x.'tl haJroni.: signal n,mhn.:-.mty and tnggi:r bi~-,. r.:-sultin!,l from thi: fa.:t tlwt th.: r,'\:onstructed i:nc:rgJ dc:p,:nd, on th.: stanang p.nnt or th.: hadron shower,. TI1c:-;.: pn,tilc:m> .ire ;i Jir::.:t eons..>qu.:ni.."l! of th.: non.:l.lmp,:n:.aung nature of

-..uupling lr.a.lMI fur lllll" 1 'l 1 10 - ...

::.o fJI

l .J e

lh,

'5 I~-

I_;;

l.ll• • CDf Pluc • CllfCnu:ll

OJI I

-

'

Ill

,,~ ,. : a JH,,l~bl a I ·\to.!/ I 0 (.\~OI

Fd~nt

1n1

1b,

I,..-

.:0 _I_O _ _,! r .. -;~

! Pb/scinr

1! ..

tri. 1 l. The r. /r ¥il!uc of ic\\.T~J Fe v.'Ul:UlUtL1r .1.'lll Pb ....inul!.at'1r wlonnu:t'"-n .u .a fU1-:a.::1un vf ~ umplin~ fr.11."':k.Jn for nu~ t tL>p .UL,J.. M the: \jolumc: r:iuo of ~\'c ,tnJ .111.-U\'C ll'WICnJI. ll.J tbuctom ,1u-il {I J. The Ju~ lmc n:rn.-...cnt1. :.:i.: ,.J.nnpc:t.\J:hon 11."l•nJ.itaon ,~,,, = 10)

140

hm i }N90S_ N N <% N BMR5pNR0 [*qN0RSS]1 q*% , NN<R*]< <* k ]N_ <€ < INq—q05> hm sMr < j.s.j Z ( € ] E m1c l+c

/' j K _ ~ ±X— j /j ±= h 4 ' j ° K_? >j _ ; ~ XW j W [ 'j? _ W Xj ±K ? / K _ X> ±_ / X~ ? — j/'~W X= ^ =jW h

6 j ^=jW /' j ±j =^ /= ~ ! /'X= = /^ W ° /~ W j /j ±— X? j /' j ± i i / ;_ ^j= ~ ! /' j K_ ~ ±X— j /j ± _ ? W X/= =jJ— j?/=h 4 ' j =j /^ ±? j W ~ ^ / /~ >j vhEQ #X'hWp !~ ± /' j w- =jK /X~ ? _ ? W mhnr # shsc !~ ± /' j q x , =jK/X~? * ±j =% jK /X; j I'h 6 j K ~ — % _ ±j W /'j=j ; _ ^ j = [ X/' /'~=j ~ ! ~ /' j ± v♦> = K X? / X _ /~ ± _? W B j = K X? / X _ /~ ± K _ ~ ±XE— j /j ±= _ ? W !~ ^ ? W /' _ / /'j° [ j±j X? J ~ ~ W _J±jjE— j ? / [ X/' /' j ; _ ^ j = j]%jK/jW ~ ? /' j > _ =X= ~ ! /'j =_— %X?J !±_K /X~ ? h

0 j!j±j?Kj=

T v ' 0 h 6 XX=±X^?U h P ^ K ) _ ±hW - j /' h x a c b Tmb»K47 nZb

Ta7 Q k _ ? W h 0 h 6 XY — ~ ±^ h P ^ W h v/X= ± h ^ ^ W - K /Xh x usb

D- ! 8 K ? — h j / _ I h P ^ W h /_UX± _ ? W - j /' x 3 j ' &» . ' auhAh ■u ’ y K ' ± K X; ± / _ X h h P ^ W X ^ X ± _ ? W - K /!/h x a1l d mbUF'' m m »

"c’ g , B g ~ X_ /~ ± _ / X^ ? h 4 ' j g , B vv 4 j K ' K XK _ , j ^ J ? 0 j % ~ ± / h B K ±— X) /> v ? /j ± ? _ 0 j % ~ ±/ Z'3 nUU'Ewh ^ ? % ^ > X=' j W e - xh'±/+[ ♦v 7 ) h 4 1 g , B L!/Y/ h♦%U+±_W/! j j K /±~ — _ J ? j /XK

K _ ~ ±X— j /j ± h /j = / > j _ — ±j=^/U h P ^ W h D? hC/± h _ ? W - W ' h x ©m=/' Xa/U+a' cau

or ’ - B ± _ ^ / = W ^ j / _ h 2 /W W = h K ~ — % ~ = X/ X~ ? _ ? W % _ ± _ W j

^ XK ? / X? K _ /9 — /~ /' j m bbr g , B ] £ N 1 ^ ± _ h g , B v ? / j ± ? _ P ~ [ z v b c h mbbroL W j y _ ±> _ ±_ j / _ X hh L _ ± / XK j K ~ — % ~ = X/ X~ ? h ~ ! /' j - 4 r Z K ^ ?

/^ ± hj = ! ~ ± /' j (f g , B e ~ / > j _ — h g , B v ? /j ± = U I P ~ /j u s r c h mbbp

DUUV k h , ±_ 9 j * j e ~)h P ^ W h v / ^ / ± h _ ? W - j/' h x a r b X b Z U X rmUh

l m q h x > ± _ — ~ _ Xj ± h KI _ W P ^ W h v = + / ± 7 ? z - j/'h x v l s Tm b c m ' uab

&&- 4 h C E g XW ' ? K h j _ h P ^ W = l / ± h+?W - W ' x ’ ’b Z u + U1'

Dm+v Q k ^ ? K X 0 h 6 X — _ = U h P ^ W h ? + /± _ ? W - W ' h x h1lc »mbbcX q8

Tv ’ , k ± j j ? h , X7K / = % j W ± — K ~ % ° _ ± = XY ' ^ — X? ~ =X/° h B K ±— X) X' 0 j % ~ ± / B K ±? ^ _ > Eg ~ j !E A5 ' mcmh m&lzs

vmaz 0h 6 //!? ^ ? _ h g _ 8 X ± / / ? W ± ° # w ? j ±J ° - j _ =^ ±j — j ? / — L _ ± / X W K L '°=XK=h v ? / j ± ? _ / X~ ? _ Z K ? j = ~! - ~ ? ~ J ± _ % ' = ~ ? L ' ° = X~ h 1 ~X msph Q ] ! ~ ± W )&/^;K±; XeC L ±KU ; a!U5'h % u 8 *1B

mmnm - q _ ^ j ± W 7m h P j W h D h_ X± _ ? W - j/Xh mcI v P p ] X r b h ± x 9 K /= ~ ? h j / 7) h P ^ W h 0 l e± _ ? W - j /' C aum +v b Z c m vg h z Ax J — /[ X h j e 7 ’ h P ^ K v ? = / ! _ ? W - j/' x aNAu ’ ’ * X» b X mnuh

w h TvK0 ; X±W Xh j / 7 h h P ^ W h v?hR/± 7 ? W - j/' h x ara m m b s EEmUo, h x j ^ _ /_ h j _ X hh P ^ W h vhE[X±h _ ? W - j/' h C ; /= / %lb+* uZm

♦/ u 7 4 Z ^ j ^ 9 Xh j/ _eh* P j W v? U e± _ ? W - W e x una u]

mum


lhe calorimeters. They .:an be a\·oid.:d when a dilf.:n:nL .:a.libr.uion mcLhud is IU<d.

We us.:d Lhe re:iuhs of 1hi5 study le> determine Lhe t!/l1 valuo of the .:a.lorimc:t.:r and iu oc:gmenu. Thcs.: 1urn,:d out lo be l.-1:l=•J . .::7 for the: f_\l ~\.°\:lion .1.nJ l.3o=0.05 for the HAD )C\;tion. n::sp.xuvd~. We: cumpan:J lhi:se v:Lluc:s ,\ilh lho~ of ,llhc:r Ph -cin1illator ,ind Fc: s..;ntill:itor .. -:1lonmc:1c:r~ anJ founJ 1hat lhc:~ I\C:rc: in good .1gr.xm.:nt 1,11h thc: ,alu .. -:s c:.,pcc1.-<l on the: b:isrs of lhc: sampling fra,:tion.

[II R. w,~rn.m,. '.',;u.;l. J:,,11. ,r.J ~kth. A :5•} ()Q~~. ;~, ..

(:I O liJ:-:...:J. R. \\·i,-r1wru. :\ud. lr.s:r. JuJ \lct:1. .\ -MW • ,~~.h:l

l 11 r \k~ ..... ,n. d .L - :'\1~,.:I. tr.-.ir .tmJ \l1..--!h :\ ~n:' l•J!'17) ,:.1_1 [41 L' &~re"..,. e! J.1 •• :\u.a.:! ln.itr .tnd ~k"'!h. A~~,,' lYJtJt 11' r~J CDF Cot:.1hoc:.1:lur_ -The CDt-" II r1.-chr:ar.:.&J D:".:n

IL.T<•rt. Fcnrul.J!> l=t,T,1.d R<ror: '"' J'JOI-E. unruhb,i,,.-J: M Ai~n~ -:t .1!.. T!k." COF Pk~ t·r--tr:,J.: dcs::rom.r~r.rt11: i.:~nm..:u:r: ~ot Ol."".im r~u.lt.-. ~~ (:btr . .>c.J \li.::h.. :\ ~I) t:£10_:) 5.:J

141

(61 !I.I ~ r;wt,ch1 ct .d.. \" ll!!J.. .:omro-10011 •~.d p,ut1&:!r tdcntllic;ulOII m ~ 1'1116 CDF :o,t ,._,m_ CD~ hu.:m.&I :-,;.,.., Jl95. 1'196; P de B.ut'Qroct .aL PJr~~Llmf""l~rkmofthc \IT6 ~ tur.;,, c~r t!:c 11.1-17 CDF :1,,"">t ~m. {"OF hULT::ii! ~tJt.: -I065. l'l~1'

'"'1 G. o,,.l.:. ,-: ,L :-.u..i. hu:r. ~n.i '.I.I.:!: . .-\ ;6•1 t 19~~, M

:SIU. Al•umv11,..,.,_cL1~. :0-~ci. ):,.,tr ar.J \kt!\..\ 1--Vll"'I' ,~ :111 T_.\_ (i.1t-inc:. \."t .,J. . :"-a.;...-! l:::a.:r .1:1J ~krh -\ nS, 1 !'~I

1~

[l•il O G..n..-1. R. w,~nia::>. :-.oo. I:,.,~ ,a.J ~k!h .. \ _:,,5 tl911~1 iii.I

[I IJ [) Gm:n. °'"'! ,pn.-:ru,,:,,r, ~, "I'-~ lwn1n.N:~. ~-,Tmi.lJh R.:I'"" l"crnu!.i;..C .,.,r.•JO. I 51. l'•JO

r1:1 R. \\'1~m.iru.. CJ!unn-.:~~-Er:cri:- \1.:.l'IIUll:tu..:nt ,n P.1rt~~c l"'i~"'- lnt.:r:utMf"..1> Scncs '-'' \f,•:1,,tr.1phs u:1 P=~w\,..,. v..n. I():'. Ch.forJ L"nn.:rw:\ rn.:., ... ZfV)O. p. ~11 :r.

!L'l ~1- 11,uJ,:r. 1.""! .al. ,ud. (:i:.tr .1:iJ \kt!1. 1~111"".°~t fH •

f A.1.L~··->~ ~, JL. ,u..:!. (r_ .. :r ;a::&J ~It::~. \ =-u 119~~ I I"': L. J'.-\~1~:uu . .:: .JI • ~u~J lr-.:i.rr .,!'1.t..l \k:h ·\ :--~, l 1'!'l'h 1.1-1. E. lk"fT'..1t1ll. ct ..1L Su~!. ln...rr .1n,t .\11."f!l. :\ :tt: f 1,,..,.~, ~:'I: 0 .. ~w..u. e. .t!... :\"t.:a::. l:l .. -.:r . .1::d \kth \ il)~ • i'>-l ! , ..._,,u

ti~) ·r Su.cul,. ~1 J!.. ~L.°I.:! J:u.:r .mJ \J..:c:1 A .&J.! - l·l'W1 •~

x L L w P , v5 g

QP 4 q w w P w 0 k 2 - w x Z8 0 w - w P 4 Q B q x , 0 Q P zw 4 Z Tx g g w L 4 w , B Q 0

L 8 y ) vg x 4 vQ P vP P 8 g )wx 0 vP Z40 8 - wP 4Z x P , - w 4 q Q , Z x'

mua


.-\PPEXDI.X C

O;\ THE E:\"ERGY :\IE.-\SCRE:\IE:\"T OF H.-\DROX JETS (ACCEPTED FOR

PCBLIC.-\TIO~ IX XCCLE.-\R I:\"STRC:\IE:'\TS .-\~D :\IETHODS .-\)

1-12

x ;_X_>j ~?X?j _ / [ ; [ i7K j ? K j W X±j K /] ~ —

■ Q(PQvYyvqvQ4A /-4PQP-L-1ZgZ

w ) Z w 1 vw 0 P _ W j X ± v ? = / ± ^ — j ? / = [ X - ? > K X X X > 0 j _ _ ± K ' x ma s s a ' m sp maI' Y

;+YhYlQ(/zhA _X(_K&X X8X

r* ■,k k*k]~D ¥kc’£]k¥k*■ ^ " ,cJ]^* _k■’

r>~c i^((c*C u]c|p*J,c* h]p,c]c*C tpy,c]J ap~¥c*’Ti1Y»)Xi!*;X±A/hE h ; i ♦E A X A X X X h v 1 [ 7 "DOu / X ^ X j ? / h ♦2 W R < E:d*ZE w ^ i6 — ) 4 1 p1 zs1 hiQ Ui O W v

9 K E K X ; _ e h 7 z ^ ° a [ a ±K) g /;?o 7 X — K j g / h h/‘ aUh x E ^ ♦E— a»lae y ~ ] % /K W ac x ^ K ^ = X ah- a

_>=/±_K/

4 ' j y>k¥y]C>_]D K ^ K = / X ^ j w / X ^ ! ,cp>]£¥y ¥_>■k] T * X X E X ±9 h; E ) x ± /; h ^ a ^ ~ j 7 v ) ? 7 ± E v / ± ^ / I e K — + j X ; + j ] % j ± X — j ? / _ ° p]C e' j "^]¥ ~ ! 7 ^ / = ~ ! % _ ± / X K j = h 6 j — ; K = / X = _ j /' j % ± j K X = ^ ± _ ? j > _ v ? K ' e ' j k*k]~D ~ ! ■ppy’k / ± _ J ? X K ? / = _ ± £hD|H■c p]cp■ > j

± ? ~ 7 X ) ± ! X v e;EhE ± j _ / X ; j _ ? % X X ± / _ X ] , ~ ! m I ej >5’■]£p8BCdC■c* — j _ = ^ ± j — j ? / % ± K K ^ ^ = ± h _ ± h W ~ ! X j oK _ J ~ ± X / ' — )X _ = = j = = j = o 117

_ = ~ k|c>£c■k X j N K ? K ± ^ ° p^W A ? ] E / ' j W h X ? [ ' XK ' ■^k K ! ~ ± _ ^ X X ~ = ■]£¥ _ y,c]ck|>*•c]■py>y h AK j K j ± X= / Q ] ? > X ? j z _ ^ > A h j _ /

v ± ~ ? X _ K _ ~ ± X — j / j ± p* ~ ± W j ± ~ X e ? % ± ~ = j >pk p Em j ? j ± J ° ?hE=jEo)h^zeeh X A EFFTFE >&£*C£,^) (D !K h= j ; 7K 4 hypk*yk lCs

k B < S sa m' hE_h aU u^ C o

x j ± y ~ i X X K g _ 9 ^ h— K / ± ° h q ^ K ^ + h~ X = E X W U h w ^ K /^ ° X / AU

FC 2*■]^J£y■p^*

- x !/j ± _ ] ; hK 9 ? ~ [ ^ K ~ ? = X = / = ~ ! ZK%/~?= _ ? W * ^ _ ±9 = h 6 ' j ± j _ = /' j % ±~ % j ± / Xj = ~ ! j % /~ ? = =^ K' _ = j j K /± ~ ? = ~ ± — ^ ~ ? = K _ ? ^ ^ _ ° > j — j _ =^ ±j W [ X/' _ ; j ±° ' XJ ' W j J ±j j ~ ! % ±j K X= X~ ? * / ' j = _ — j X= ? ~ ± / ±^ j !~ ± * ^ _ ± 9 = h 3 ^ _ ± 9 = _ ±K N ~ K 9 j W ^ % N /? = /W j — j = ~ ? = ~ ± T _ ? / X E 7> _ ± ° ~ ? = _ ? W _? ° _ / / j — % / /~ X=~ _ /j /' j — K ±j _ /j = — ~ ± j = ^ K ' % _ ±/XK j = h v? ' XJ ' Ej ? j ±J ° = K _ / /j ± EX? J j ] % j ± X— j ? /= _ X— j W _ / = /^ W ° X? J /' j X± % ±~ % j ± /Xj = * * ^ _ ± 9 = * W X * ^ _ ± 9 = ~ ± _ ? / X E* ^ _ ±9 = ! ± _ J — j ? / X? /~ [2’ ~ ! ' _ W ± ~ ? = h

4 ' j % ±j K X= X~ ? [ X/' [ ' XK' / ' j % ±~ % j ± / Xj = ~ ! /' j ! ± _ J — j ? /X? J ~ > 7j K / K _ ? >j — j _ = ^ ± j W W j % j? W = ~ ? /[ ~ !_ K /~ ± = e 4 ' j 7j /EW j !X? X? J _ J ~ ± X /' — _ ? W /' j

W j /j K /~ ± * ^ _ X /° h 8 =^ _ ° * _ °j/ /; W j !X? j W _ = /' j K ~ j K /X~ ? ~ ! % _ ± / ] K = /' _ / !_ [ X/' X? _ K ~ ? j [ X/' ~ % j ? X? J _ ? K j x j— j ±J X? J ! ±~ — /' j X? /j ±_ K /X~ ? ;j ±/j] h 4 ° % XK _ ; _ ^ j = ~ ! x* [ ' j ? j] % ±j ==j W X? /j ±— = ~ ! _ ? X? /j ±; _ X? ±7h „ ;%_Kj

vx f i;_& # xXu<'h ±_ ? J j !±~ — Q z /~ s hp h v ! /' jK ' ~ =j ? £ ; _ ^ j X= _ ± J j /' j K ~ ~ K — _° > j K ~ ? /_ — X? _ /j W [ X /' % _ ±/XK j = /' _ / ' _ ; j ? ~ /' X? J /~ W ~ [ X/' /' j ! ± _ J — j ? /X? J ~ > 7j K /* X ! x X= =— _* =~ — j 7 j / ! ±_ J — j ? /= — _ ° > j ~ K_ /jW ~ ^ /= XW j /' j K~ ? j h B ^ K /^ _ / X~ ? = X? /' j 7 j / j?j±J° K ~ ? /_ X? j W [ X/' X? /' j

7j /EW j ! X? X? J K ~ ? j !~ ± — _ ? X±±j W ^ K X> j K ~ — % ~ ? j ? / ~ ! /' j 7j / j ? j ±J ° ±j = ~ ^ / X~ ? h

x / j ? j ±J Xj = > j ~ [ mss k j 1 h /' j K ~ ? /± X> ^ / X~ ? = ~ ! /' X= X± ±j W ^ K X> j K ~ — % ~ ? j ? / _ ±j = ^ > = /_ ? / X_ _ ? W X? % ±_ K /XK _ j ] % j ± X— j ? /= /' j° _ ±j /' j — _ X? !_ K /~ ± X— X/X? J /' j 7 j / j ? j ±J ° ±j = ~ ^ /X~ ? h q ~ [ j; j ±* _ / ' XJ ' j ± K? j ±J ±j = h 7 j / = >jK~— j — ~ ±j _ ? W — ~ ±j K ~ X— _ /j W _ ? W /' j K ! K K ^ ~ ! /' j °j/ _ J ~ ± X /' — ~ ?

“6pH]]’•y¥)pppc _£■,£]C dkiC C F *(r]j*=*>E*===‘R p* C * ;C=?U=hpu♦ h X e] a h

±T¥£ q E $ 0 N < 1 Wp*]*c*yCp ■*ykk£ NtC a£ycc]£>C

m'm -E-UIs a eka c ■ ^ =j v ±~ ? U — _ X j ± g a m 's a L ^ > X = ' j W >° w = j ; Xj ± Z K Xj ? K j y h1 h

L m) Z X Z Z E b s s a m s a ’ s / _ / Z h p

mun


I Availab'e onllne ill w-.sclencedirect.com

•o•••o•@DueaoT• NIICll&a ~ -~ •,tlYIICS

--·IICN ELSEVIER d«.V"

On the energy n1easure1nent of hadron jets

Olg-.1 Lobban. Aravindhan Sriharan. Richard Wigmans•

.\bstnct

Titr d.:m.:::: .. ~· ,'\ln>ttt~(c:.. ur luJro= m.it:tr (4u:1th ... c:1-4~.ut... !'!u<>c.sl :n:1:1:: .. -.. t!::.:r:1..:i·.~, ~.,.-.,run.:::wJ) m !h.: f'-'1'1:1 ~,f ,teh llf par~1i.::t.~. \\'1! c·.~:.i~:c: l!u: prt:6-'.n.aLJC wtlb -.t.l:1d: !?!.: t:~&:r~:• LJ:· ~~c,~ !Ja.~r:u:~:~"t~ u~_-.., . .-:.s 1.-..a.n :ati: m..:-..1s.urtt..f. 1:~ r-Ul1-.~ :n:pnr':a::-.J.!' ... ,r ~~ ::-...st:t.m.:~w..: tr ••• :.n,L:.fL"t:n:~r ('tn'\.:uwr. J:!J llf ~t.!' ;C'! .1:::-~1!'1:!.:Cl b .l~'!Jc.."L!. \\'.:

;,il:.c.., c\::.ll!!.tl&: t~ 0 ct:.c:r~ !!oi.,. ·• n:cU'--'1.. u i.\.hlL.-:? :.ll.l! 1c!°LJr-JL1:..t.>:: :·nun a ..::t.u~~;=--~r!t'l.'.:I! lr.K.ir:r 1~ \.~--:ab~r:J -,1i~!.,: :;ut

!:ui:n ~ oiLJnn:&:!cr m. l?r..!rr ~u 1:npru·.c :.l!c r,.:! ..:-::.er:-~· ~-1L::u.:::... ,· .::t:11: 1'1:::>.u::,.-J :,~ t~'""-'T s~1c:':1,e B. \'

l. l11uodlldl,on

'.\l.1tter .u '11.c k.uuw il coiwsts of lcplons a.nd quarks. Whc::rcas the propcmes of leptons sua;h is

dcctrotU or moons.:::.n u..u.illy ~ ~urtli \Hlh _.

very high dc-gra: of pro."iiion. the !13.JnC is n.:i1 true for quarlu. Quarli.s ue .. locked up .. Lns1o.ic mesons or (anu-)bacyons :and :llly attempt to isoh11e them crcales more such panil.h In high-<:nergy 9Clttc::ring cxperimenu aimed at stud~·xng their pro~:..:s. quarts. diquaru or a.nti-qu:ulls fragment int.i }<'l!i

01 haJrow. The prc:dsion with which the prnpcnics of the

fragmcnu.ng object c-.in be mea,iurcd dcpe,kl:s on l wo faL"tors: Toe jct-defining ali;orithm .1nd the

•Cixrc>PJni.iJI!. ~IIUlo.6. Tc:L - :~T.U,l-r:'9; 1a • l· 1111~1~1.1:c.

£.,,,,,,; >A!.:,,t..U. w,~=ru:,i ruu.:u 1R. ur~1.

detector qualit:;. Usu.ill:,. a ,ct :s &tined J.S the .:nlla:tion i.>f parr.x!.::s tlwt fall \\ltlun a .:one wit.Ii opcwn~ .uigk R cmcrgm~ irom the: int«:r.lcllon \ertC1. T)pic:u values .if R. \~ bcn c.,prascJ in t.:r!ll!I of :10 1nta\;u i.n f/,.;, ,p:i~c

IR = ,_/.1,,= - ,:1Ql). ran!:,-.: from 1).J to O. 7. If lhc d1osa1 R v:duc is lar!:,'C. lhc .:occ: Ina) be .:on1amm.11cd "'ith paruc!cs :h.lt luo,:e iwthing to do "'ilh the fragmenting objcl.."t. If R is mull. s.:,me jcl fragm.:nu m;ar be located outside the cone. AuctWlti,ms in lbe jet cucrin, oomamed wnhln the jct-<ldiniug cone fonn an im:du.:1blc component of the jet <:ncrID· resolution.

At energies bdi.>w 100 GeV. the contributiorui of r.hill irrci.lucib!.: componcm a.re iUbstantial .:inr.l in pra..-tic:il experiments lhey arc the main fa.:::ur limiuog lhc jct c:icrgy resolution. H.:-wc\cr. .u hi:'.hcr cncrg:cs. jets b:comc more :100 more .:ollimatci.l .JJlr.l the effo:u of lhc JC1 3.lg<>rnlun on

l)tM.'IOO~O! S • iee fran,c m.ui« o1: :OO:! Pul,fahed I>, EISC\tcf S.:lello% U. V. Pit StiUli-iO0:?10:?11ll!il s> .

143

~ / l d*))Z^Y ^ ^ *UW ^ > 6 : K^ \Y(U;0^0qY u i j ~ 6 X X >dn:q^;;— c Sh)lh_ Ul B L Vh l

/' j j? j±J ° ±j = ~ ^ /X~ ? W X— X? X= ' K ~ ±±j = % ~ ? W X? J ° h v? Z j K /X~ ? a ~ ! /' X= % _ % j ± * [ j X? ; j=/XJ _ /j /' j j ? j ±J ° W j % j ? W j ? K j ~ ! /' j =j j !!jK /= h

Q ? j ~ ! /' j % ±~ > j — = X? W j =XJ ? X? J K _ ~ ± X— j /j ± =° = /j — = !~ ± — ~ W j ±? j ] % j ± X— j ? /= X= /'j !_ K / /' _ / /' j ±j * ^ X±j — j ? /= !~ ± j ] Kj j ? / j? j±J ° ±j = ~ ^ /X~ ? ! ~ ± 7 X? J j ' _ W ±~ ? = _ ? W 7 j / = _ ± j ~ ± /' ~ J ~ ? _ /~ /' ~ = j ! ~ ± ' XJ ' E±j = ~ ^ /X~ ? j j K /± ~ — _ J ? j / XK / j ? ' K _ X~ ± /— K /±° D m Vh q XJ ' E±j = ~ ^ //~ ? ' _ W ±~ ? XK =' ~ [ j± — j _ = ^ ±j E— j ? /= ±j * ^ X±j K ~ — % j ? = _ / X? J K_~ ±X— j /j ±U h x ? W K~±_%KXXh;^ /X~? T)jh j * ^ _ K _ ~ ±X— j /j ± ±j = % ~ ? = j /~ e' K K— _ ? W ?~ _ EK — K ~ — % ~ ? j ? /= ~ ! ' _ W ± ~ ? ; > ~ [ j ±= h 2 x # m h s m X= ~ ? ° 7j ' Xj ; j W v? = _ — % X? J K _ ~ ? — j /K ± = [ X/' _ ;j±° =— _ =_— %X?J ! ± _ K / X~ ? * j hJ hh a En R X? j_W* % X_ = /] E = K X? / X _ /~ ± = /±^ K /^ ±j = h Q ? /' j ~ /' j ± ' _ ? W h ' XJ ' E ±j = ~ ^ /X~ ? j ±_ =' ~ [ j ± W j /j K E/X~ ? ±j * ^ X±j = _ ? X? = / ±^ — j ? / [ X/' _ _±Jj = _ — % X? J ! ± _ K /X~ ? * j hJ hh ^ ^ R X? K ±° = /_ = ~ ± l u 8 l X? W j /j K /~ ± = =^K' ]= /' j PxxZ ) ( ± K _ ~ ±X— j /j ± DaV*

v? ~ ±W j ± /~ =~ 8 K /' X= W Xj — — _ * X/ ' _ = > j j ? % ±~ % ~ = j W /' _ / ~ ? j K ~ ^ W =XJ? X!XK_? /° X— % ±~ ; j /' j % j ± !~ ± — _ ? K j ~ ! _ % ~ ~ ± E ± j = ~ ^ / X~ ? ' _ W ±~ ? XK K _ ~ ± X E— j /j ± =° =/j— >° K ~ — > X? X? J X/= X? !~ ±— _ /X~ ? [ X/' /' _ / ~ ! _ ? ^ % = /±j _ — / ± _ K 9 j ± X° = XK— h v? /' X= _ % % ±~ _ K ' * =~ — j /X— j= ± j !j ± ± j W /~ _= /' j kY2;UUG f'„I w2^x„m' /' j — ~ — j ? /_ ~ ! /' j K ' _ ±J j W °j/ ! ± _ J — j ? /= — j _ =^ ±j W [ X/' ' XJ ' % ±jK X=X~? >° /' j / ± _ K 9 j ± =j±;j _ = _ ! X ± = / E ~ ±W j ± j = /X— _ /j ~ ! /' j 7 j / j ? j ±J ° h Z j K ~ ? W E~ ±W j ± K ~ ±±j K /X~ ? = * X? /j ? W j W /~ _ K K ~ ^ ? / ! ~ ± /' j K j ? / ± _ 7 j / K ~ — % ~ ? j ? /* _ ±j W j ± X; j W ! ±~ — /' j K _ ~ ± X— j /j ± = XJ ? _ = h Q ! K ~ ^ ±= j * /' j K ~ ? / ± X> ^ / X~ ? = ~ ! = ' ~ [ j ± X? J K ' _ ±J j W % _ ± /XK j = /~ /' j K _ ~ ± X— j /j ± = XJ ? _ = ' _ ; j /~ >j W X= K ~ ^ ? /j W % ±~ % j ± ° ! ~ ± /' X= — j /' ~ W /~ [ ~ ±9 h - j /' ~ W = ~ ! /' X= /° % j ' _ ; j >jj? = ^ K K j == !^ ° ^=jW /~ X— % ±~ ; j /' j ± j = ~ ^ /X~ ? ~ ! 7j /= ! ± ~ — i E W j K _ ° _ / ) q L Dnzh v? Z j K /X~ ? n ~ ! /' X= % _ % j ± h [ j X? ; j=/XJ _ /j /' j % ±~ = % j K /= ~ ! =^ K' — j /' ~ W = _ / ' XJ'j± j ? j ±J Xj = h g ~ ? K ^ W X? J ±j — _ ±9 = _ ± j J X; j ? X? ZjK /X~? uh

ah w!!jK/U ~ ! /'j 7j/ _J~±X/'—

6 j ' _ ; j = /^ W Xj W /' j j !!j K / ~ ! _ 7j /EW j ! X? X? J _ J ~ ± X /' — ~ ? /' j j ? j ±J ° ± j = ~ ^ /X~ ? !~ ± ! ± _ J — j ? /EX? J * ^ _ ± 9 = [ X/' _ - ~ ? /j g _ ± ~ % ±~ J ±_ — / ' _ / [ K W j ; j ~ % j W !~ ± /' X= % ^ ±% ~ = j h 4 ' X= C ~ ? / K g _ ± ~ % ±~ J ± _ — X= > _ = j W ~ ? _ 'XJ'° = X— % X! Xj W

± j % ± j = j ? /_ / X~ ? ~ ! /' j %'°=XK= % ±~ K j == j = /_ 9 X? J % _ K j X? % ±_ K /XK j h q ~[ j;j±* X/ W ~ K U K ~ ? /_ X? /' j j = = j ? / X_ W j — j ? / = ?jKj==_±° /~ j ; _ ^ _ /j /' j j? j±J ° W j % j ? W j ? K j ~ ! /' j K ~ ? / ± X> ^ / X~ ? = ~ ! /' j 7 j / _ J ~ ± X /' — /~ /' j ±j =~ ^ /X~ ? h v ? ~ ^ ± % ±~ J ±_ — * /' j ! ± _ J — j ? /_ / X~ ? % ±~Kj== X= J ~ ; j ±? j W >° _ ! ± _ J — j ? /_ / X~ ? !^ ? K /X~ ?

, d o / f d X E v / E U T m '

X? [ ' XK ' , Xj v W j ? ~ /j = /' j % ±~ > _ > X X /° /' _ / _ 7j / ! ± _ J — j ? / K ~ ±? K = _ !±_K /X~ ? G ~ ! /' j j?j±J° ~ ! /' j ! ± _ J — j ? / X? J ~ > 7j K / DuV* 4 ' j % _ ±_ — j /j ± A K_? > j K ' ~ = j ? _ = W j = X± j W h v/ ' _ = >jj? W j — ~ ? = / ± _ /j W /' _ / _ !^ ? K / X~ ? ~ ! /' X= /° % j JX;j= 7 ± j _ = ~ ? _ > j W j =K ±X% /X~ ? ~ ! /' j ! ± _ J — j ? /_ / X~ ? %±~Kj==j= — j _ = ^ ±j W _ / )q L _ ? W _ / /' j 4 K ; _ /±~ ? h !~ ± % _ ±_ — j /j ± ;_ ^j= A f n _ ? W r h ±j =% jK /X; j ° DcV*

v? ~ ^ ± - ~ ? /j g _ ± ~ % ±~ J ±_— * 7 j / !±_J — j ? /= _ ±K J j ? j ± _ /j W [ X/' j ? j ±J Xj = [ X/' /' j ; _ ^j= ~ ! ± K';^hK? ! ± ~ — _ W X= /± X> ^ /X~ ? ±j % ±j = j ? /X? J )*h m m Xh q ^K' ! ± _ J — j ? / X= _ == XJ ? jW _ K ^ = = + mh _ K ' _ ±J j _? W _ / ± _ ? = ; j ± = j — ~ — j ? /^ — ! W 4 j ? % j ±K j ? / ~ ! /' j % _ ± / XK j = _ ± K _ = = ^ — j W /~ >j 9 _ ~ ? = _ ? W ?X?j/° % j ±K j ? / % X~ ? = h Q ? j E/' X±W ~ ! /' j % _ ±/XK j = _ ±K j j K /± XK _ ° ? j ^ /± _ * /XK ±j=/ _ X K K ' _ ±J j W h 4 ' j / ± _ ? = ; j ± = j — ~ — j ? /^ — /; K ' ~ =j ? ! ± ~ — _ ? j ] % ~ ? j? E/X_ ° !_ X? J W X= / ± X> ^ / X~ ? [ X/' _ — j _ ? ;_^j ~ ! s hn k K 1 i j h v ! /' j K' ~ =j? % _ ± _ — j /j ± = °XjW _ ? ^ ? % ' ° = XK ? ±j = ^ / * j hJ hh X ! /' j K ' ~ = j ? — _ == X= _ ±Jj± / ^ ? / ' j ! ± _ J — j ? / = j?j±J° ± " * E / h ~ ± X! /' j / ± _ ? = ; j ± = j — ~ — j ? /^ — X= _ ±_ K ± / ' _ ? /' j /~ /_

— ~ — j ? /^ — ° ± q 7 E / ' A L Y ; ' /' j ! ± _ J — j ? / X= W X=EK _ ± W j W _ ? W _ ?j[ ~ ? j X= =jjK /jW h 4 ' j =K /jK X~? ~ ! 7 j / ! ± _ J — j ? /= X= K ~ ? ^ ? ^ j W ^ ? /X / ' j 7j / j?j±J° ±= j ] K j j W j W h v? / ' _ / K_=j * /' j j? j±J ° ~ ! /' j )_=/ ! ± _ J — j ? / X= ±j W ^ K j W =~ /' _ / /' j / ~ /_ j? j±J ° ~ ! _ ! ± _ J — j ? /= K ~ — > X? j W j* ^ _= /'j 7j / j ? j ± J ° h

6 K ^ = j W /' X= % ±~ J ± _ — /~ J j ? j ±_ /j 7j / = [ X/' !X]jW j ? j ±J Xj = * ± _ ? J X? J ! ±~ — ms /~ msss k j 1 h 4 ~ ± j_K' j ? j ±J ° h m s s s s 7 j / = [ j ±j Jj? j±_ /jW ! ~ ± /[ ~ W X!!j ±j? / ; _ ^ j = ~ ! /' j ! ± _ J — j ? /_ /X~ ? ! ^ ? K / X~ ? % _ ±_— j/j±e ± f n _ ? W n f r h B X±= /* [ j ='~[ = ~ — j Jj?j±_ ±j = ^ /= / ' _ / J X; j _ ? X— % ±j==X~ ? ~ ! /' j K ' _ ±_ K /j ± EX= /XK = ~ ! /' j J j ? j ± _ /j W 7j /= h qXJh m = ' ~ [ = /' j j?j±J° W X = / ± X> ^ / X~ ? ! ~ ± /' j %_±/XK j= /' _ / K ~ ? = /X /^ /j _ mss k j 1 7K h ! ±_ J — j ? /X? J _ K K ~ ±W X? J / ~ q f n ~ ± ] f r h v ? B XJ h a h /' j W X= / ± X> ^ / X~ ? ~ ! /' j 7j /

muu


IOII

the C1lCl'gy roolu:loo dimutisb .. "Orre:1pondio~~. ln So.."tion :? of this papc:1'. 'A(: in,-cstiptc the energy depcndcoo: of tbc:ic dTcas.

0!.11: of the probk:ns in .!..--ugmng Clllunmc:.:r :1~SlClllS for a:o.!em apcruucnt, ill the f.a.:t t!wt the rcquirc:mcnts for a.x!!dlt cilCrg n:soluuoa for :1inglc h.:ldrons .1nd jcu ,uc onhoi;onal to tho~ for l!l;;h-ro.,lutiun e!a:troma;;ru:tic 1cm) ~-aionmC'lrf (1). ~'l-roulut111n h.i.ironi.; s.hll~'« mcasuccm.:nu n:qum: .:ompccsatmg .:al.:-n.'llctcn. .-\nil i.:ompc:-.11:Jt:on li.c. ;:qual .:alomr ... "tt:r re.po= lO

the ;m and n,1:1-,;:m .:llm(~ncn:.. oi haL!w:1 ,r..,, ... en . ._,!/1 = 1.01 i, onl} .i.:hinctl in s .. mplini: .::;ilonr.-.c:cr- 11, 1th .i \ Cf) ,mul? ..amp!ing fr:.1i.:tiut1. e.g.. 1.3"·• in !c;.id plascc-;.::umlutor ;m,._·u::c:s. On the .:ith.:r hand. h:~h-~,luti,m em ih,mer dC!c-.:· u.:on r=4i.;:r~ an m . .trument w:th .i ur;;e samplmg fr-a.:t11m. c.;;.. IIJu·•. L."l .:i;,swls Llr :,. 41.1· ., in ..!c:.:.:t.:,n 'hld1 :u t~ :-lA.t.'I LKr .:aionmetc: [:l.

In Mlkr ll) ;.:,l\c this i.!i.!c-mma. 1t has b<.--cn propoeiC\! th .. : om: .:oulJ -1i;;nii:.: ... ntl) unpr.:i,c the pcriorm.1.:i..:: .:if .1 poor-res.:il1a11.:11: h.:idrnn~ \.':.ilurt· meter ·~•tc-:?l b:,· .:..-,mbm:n;; tl> :oformau.:in 1ut.:1 that of .1.'l u;,strc:.im trackr i}i:cm. In lh!S

appr.».:h. somct:mcs referred :o J.i t!le En,:r,,1,· Ff.,,. .. \l<'lhvJ. the 11i..1mc11~ of th.: chJ.r;,<cd JC! fr-J.!,,T.'!Clts rn-.:a,urC\! "'itll l1tgll pm:isi,)U b~ the tr:i..:l;.er ;enc J.S J. first-order esum.ue of the jct energy. S..'\.",ll1J .. .,r~cr o..:.Jrrcctioru.. in!Clh!c:J lo .h.--count for the cei.;tral Jct c11mix,uent. .ire Jcr:\cJ from the c.i.Jonmctcr signals. Of cour.;c. the contribut:oru oi . .ho'l..::nn\; d1a.ci;cJ parl!do to the i::tl,mmctcr 1ii;nals b,n-e to be Ji..count.:d prorc:l~ f,,r this !'.1cthod to .. orl. Mcth..xb uf this t~pc ha,-c been su...-...~full}' Ilia! tu imprO\'C the re,iolucon 01 jets irom Z-,.kca)· at Ll::P [J). In So.."tion 3 of this paper. we in~es.ti!PLC the prosp;.:u of such method!> at higher energies. Conduiling :::m.uls ;ire given m Section 4.

We h.ne .tudicJ the etT<.-ct of :1 jct-ddirung algonthm on the energy resulution for fr:ii,;mc::uillf! qiwrl.:s wit!t .1 :\lan~ Carlo p:ognm tb.lt \l>C dc,cioped for th.is pl.lP,)O~. This :\lontc C.irlo program is b.uctl on J. highl) s.impliticd

1-l-l

rcprc:,ient!luon of the rh}!iicl proccs.ics tilini; place ID pl'llCtice. HOl\t:\Cf. it dues CllllUID the C!DL'IlU.tl dcmcnts oo::osal'}· to c\·:i.lu:ue tru: cn.:rgy .icpcoJcncc of the .:ontributions of the jct al;;oritbm tu I.be resolution. In our program. the fr;i~ment:nion pro.:c:ss is go\ crncd b) .1

fr:1!,,rmcn1.1:io11 fuection

11 - :)' ~=,=t1-l1.

III "'h~~1 D1;1 Jcn.itc-s the pNbab1l:ty th.it a jet fr:i;;r=:!l .:..:!"!CS a fra..:tiuc : of the ena;;~ oi the fr:i!,!"rnc:!l!U,! obp;t [4). The paramet:r i i::u1 be .:hu5<::l .IS d.:s1rcJ. It lw,; !X.-Cl! t.!cm~n.,u:it.:J t.lut .1

fu::..:twn of thlS IHIC ;;:\a .i ri:a.svnabl.: Jc:,cnptt.J'1 ;:if th.: fr:igmen:.niun prn\.--:SS.."' :n~.L,urcJ JI LEP .ir.d at the l.:~ J.t:on. for ;x11".!.-:!ctcr \J.k.-.:s 1 : J .ir.J t-. r~-spc.::.l',c:ly [SJ.

In our \h1ntc Cat!.o pro~r.1m. )Ct fr:1!,!mcn:., .tre ~,;;1JCl'Jt.;.i \~tth ,:;\C:C~le~ :£,,1, ,1,1[;\ the \.l[u~ ,if; ..:h.:.,,,__-:i f:om .1 .!1,l!ri:=-u:1un rcprc:s.:n:1:1:! E..i. 1 l 1.

bu:h fr'1;,.'l:lcnt Li J..'i.\!~O.:-d a cu.um . .1.:h.1r;;e .inJ .1 tr~,cr1e m,Hr.ct:l.lm r . Ten pcr..:=m oi :he pan.c!.."S .£tC :1..-..,1.rnctl :.i be bons ;1:td mnct:, pcrc,:nt pt.iru. Or..:-t!urJ ,,f the partt..::Cs Jrc

clc.:tri..-:J.ll~ ncutrJI. tl:.c rct ;ue i:!:i.1r;;c:u. The u·.u1s\·crsc 1114,mcntum t, .:h.:lS..--:t fr.>m .iu exponcn· u . .ill~ fall:ng distncuuon v. 1th .1 mc;in ,·al!>.: .:,f 0.3 GcV/c. If the .:h<>;co p.1C.:unc:crs ~:.cld an u:ipb.:,_;,ji::i.J result.-=-!!·· 1f the .:ho,cn ma» 15 ~gcr tlun the fr.1gment' s c1cri;:. :£1«. or u· the trans,-= momcnt:im L~ Iar:11=r tfLln the total

n:umcntum \/1:Er-1-1: - nr. the fra!::,"mClt i> di...-=~-t!cd .. uJ a n~- unc i:i .clo.:teli. n,c sda:u.in nf .JCl fngrn<:nts is conunue,l until the jct cncr_g} ::s c."«-'CO.icd. In !!wt c:ue. the enag) of th.: I.lit fr:i.gmc:nt is rccuca! ;o t!ut the roul cnerl:l) of 311 fr.1brmc:nts combini:il ~~ the JC1. c:11:rin.

We U5Cll tbl.!I program to gcru::r:itc jets "·it!1 li.\C\1 cnergu:s. ranging from lO to 1000 Ge\'. For .::t.:h cnerg:,-. 10000 jets were b'C!le:atC\.I for t-..o different \·;ilucs of the fr:t1:m..--:tl.1tion fon..:tion parameter: 1 = J :inJ :z = 6. Fi.r,it. 'AC ;ho\\. s\lmc ~al rc:sulu that £)\'C: an imprC!..'1100 of tbc ehar.lo:terisucs of the generated jets. fi~. I shows the .:ncrru, di>'tribution for th.: panid,:s tlut coruututc a lOO G:V Jet. fr:igmcnun~ a..1."\lriling to z = 3 or z = 6. lo Fig. 1. the ilimibation of the jet

c zh±X!/WXX 5 N 'p [ WR5vN—0 [NRq^ NR*q R*E ,'0v£hNN $N :q _ , < Ed $N—0%] } ) x ♦z6)1 f J <]d

"—

■l

s P'

Us

"—±±X7l Tkj1X

B /" m w _ K ±; l T X X h / ± h> ^ / X~ ~ R : 7 ^ ? J j U J j ? K ±E X_ XX h_ /' j ± ± _ / ! /K j ? X_ /x - K _ 8(' g XK 1 l±/ U XK^ d X) _ /! /~ < Q A m<■ [ X/' X # ' lL p N3B — % K K / e ; K ' h

2 "

r

_ E Y

v

vVs X~ o^ G5l us o~ /~E 4W

- ^ /X% XK X/°

BXJ ph -^'X%/^=X° XX^?>^)~_ w !±_J?=K~/X !± h^ eK~ kj1 o Y X X h X ? _ X K j _ / ^ ^ _ _ A/ ] W — ] TEn !5 v o Xh [ X /' X # m X _ 7 X # LX

??%~E?=j/°

!±_ J — j ? / — ^ /X% XK X/° X / J X; j ? ! ~ ± mss k j1 7j /= _? X / > K _ ; j ±_ J j — ^ /X% XK X/° X= = ' ~ [ ? _ = _ !^?K /X~? ~ ! /' j 7 j / j ? j ± J ° — BXJh n h

v ? = % ^ j ~ ! /' j _ ±J j ? ^ — > j ±= ~ ! %_±/XK j= K ~ ? = / X /^ / X? J /' j 7j /= * ~ ? ° ±j _ /X;j ° !j[ %_±/XK j= K ~ ? / ± X> ^ /j = ^ > = /_ ? /X_ ° /~ /' j /~ /_ j?j±J°h 4 ' X = X= _ = ~ ='~[ ? X? B XJ h nh B ~ ± j]_— %j* X?

cs

af /~ CEhc* +

c u_ a

» ■ U —X —0X-~/° ■ X/»!X —*^^X° LE v)M wUU

XE ;U jU [!Kj6X=j * ■ A6XL!(Q 1U8U9!Kh

ms

m s m A 8 z » U l

zj/ j?j±J° Tk j1 '

X 7 1 q j 7 / j ? ^ hU . ! ± ~ h= - _ X _X]ê — j < 1 N 0 < $ —_ ± j / j ± $ : /? J = _ ? ? ^ ' X X <h K — X K ^ X ° K ± X X X K ~ /~ Y X K ^ _ X ♦^ !

l O ' ■ } T/Xj $ 5 N C K K K ± % ° l ^ _ ^ /^ _ _ ^ / / ' j j / N* — 0 <® B /~ j X + 7

/hX♦K ± ± _ X ; _ X^ K / ~ ± UIl. ! ± \ 7 \ ± K ? ^ K ~ _ ^ _ h X X = U I % ^ ? X = ^ ! / h ! X

X f z 7j /= /' j v/' — ~ X j ? j ±J j /XK % _ ±/] Ej = K_±±° d+N©» ~ ! /' j / ~ /_ 7j / j?j±J° h B ~ ± _ f r 7 K ^ h /' _ / /_9j= mc % _ ± /XK j = * ~ ? _;j±_Jj h 4 ' X= X= /±^ j _ / _ j?j±J Xj=* [ ' XK' X= ~ ! K ~ ^ ±=j _ W X±j K / K ~ ? = j * ^ j ? K j ~ ! /' j ;j±° K ~ ? K j % / ~ ! _ ! ± _ J — j ? /_ / X~ ? !^ ? K / X~ ? /' _ / W j% j? W = ~ ? ° ~ ?

6 K W j !X? j W /' j K ~ ? j % _ ±_ — j /j ± £ /' _ / !~ ±— jW /' j ' 7hj = ~ ! /' j _ % % Xj W 7j / _ J ~ ± X /' — _ =

£ L ° Tx;l'e # Tx Ua3 g'[ 'j±j xds _ ? W x±7 W j ? ~ /j /' j = % ±j _ W _ ± ~ ^ ? W /> K ?~— X?_ W X± j K / X~ ? ~ ! /'j ! ± _ J — j ? /X? J ~ > 7j K / X? /' j _ ? — ^ X> _ _ ? W % ~ _ ± _?J j=* ±j = % j K /X; j ° h 4 ' j !_ /j ~ ! _ 7 j / ! ± _ J — j ? / [ _= W j K XW j W ~ ? /' j > _ = X= ~ ! /' j ±_ / X~ ~ ! ^ = /±_? =; j±=j _ ? W ~ ? J X/^ W X? _ — ~ — j ? /_ * ! W 3!]W v !

_ ± K /_ ? !% h iil T' l £*?

/' j? /'j ! ± _ J — j ? / !j ~ ^ /= XW j /' j K ~ ? j * ~ /' j ±[ X=j X/ [ _= K ~ ? = XW j ±j W /~ K ~ ? /± X> ^ /j /~ /' j — j _ =^ ±j W 7j / K ' _ ±_ K /j ± X= / XK = Tj? j ±J ° * — ~ — j ? /^ — * K ~ — % ~ = XE/X~ ? ' h 6 K /' ^ = X— % XK X/° /J ? ~ ±j W /' j j/4KK/= ~ ! _ ? j; j? /^ _ — _ J ? j /XK !XjW * [ ' XK' ' _ = /' j /j?Wj?K° /~ =[ jj% = ~ ! / K ' _ ±J j W % _ ±/XK j = ~ ^ / ~ ! /' j K ~ ? j h 4 ' j ±j !~ ±j * /' j ±j =^ /= /~ > j % ±j = j ? /j W _ ±K

muc


;fJ 0 ::.U .U) Nl ._I IOI

Errri;.i, tucVt

F~ 1 Lxr:,! 1?1-.tr.t'iu!u,a uf i'W111,:IN ~.cntt~1.."I! .u ttk :n...~nwr ... ,.a ...:f" ~\10 t..e\' « ...:1:"'~nll hJ r ... ':t •U.h i -} .la&! I>. n:s~e."t:\'d> - • • •

,, _____________ _,

! I

~ ~

I 1 t - t

.l

. i , -

I .- .·· IJ ' • ..~

0 1(1

-..

. · . . ·.

r---;1 e If• • f

":..

!O -'O -IO ~ W· 7(1

Multipli.:ity

F~- 1. Mu.lupl.a, ,fombut.l11 ,J( fa~, fr.:.n :oo G.,V ;,e,1. {r.ae=n""! "'-1:.x.l1J1! l-> bf- 1 I~ •1th , - I •n.i 1 - r,_

~"tl\-dy

f~rmcnl multiplidt} i., gi~·cn ior 100 GcV jct~ aoJ the ,ner.ig.c mu!uplklty l!i ihown a:. a fullCtli)n uf the jct energy in Fig. 3.

ln spuc: .:>i the ll.rgc numbcn of paniclcs comtilutillg the j:11. only rclati\cl} few p-.utido cont.,.ib111e $UbsUJ1tially 10 the toul cnasy. This ~ abo ~Ol\ll in Fi;;. 3. F.:r .::umplc. in

145

l<N

ti!),---------------, • " •,., 11.d tNtlttli.ln

1• ra•" ~1,k.-iUi1E..,. _

I•"•-' lll:ll,Ji ..... 11 ..

1 • ~.:. I 'IILJl?(11'\.n 1wt\L9~ .. i !

(I

hi l•.IJ 1rwu

Jctcnan 1GcV>

h~. l Tb: .ucr~ fr.1~1 :::.:.Jl.~I._,~ ..uw me .1.,.,:,r~c nw=.t~r Jt tr~::nu L.~t ,s :::...nu::.u.ly ~L!i;ll lLJ .a..i.:.:wn ivt "f!U•, ~ I~ .,lli:f'\ t:Ca:::f'?'f ~ ~ llllk.,i.:tQ 111 fb.c . .el tnel'~~. 1-..,f r~.,;; d.t!cr:1:u •,·;iia.a:1 ~t '.f-~ (;::~(aI.;..JG IW.").~1.'.'1 pi!Gl!:'..&!f.!'f' I

2 = J Jt:~ tl:c lo IDLtit c~i:u.: p:i.rtx:ks .:J.rr: (JO•-,. of the tot.LI JCI cncr;). Fur :, ~ 6 jc:-.i. llu: takes 15 par.1clc,;.. oo J \Cr:1.~. Thu 1.> true at all cocr,;ic.. "ha:!l i• or .:ounc .1 Jirc1;t .:.>fl>C4ucn..-c LJf th.: ,-Cf) .:o=rt of a fra~t.auon f=-tllln 1b.ll Jc-pends <1nly 0:1 :.

\Ve dcn.'11:d t!ic roac p;ir:imc:ter R th.at f.:.rmctl the b.t.>i~ of the applied Jct .ilgoouim J!i

(:!)

wbc!c .l,j) ;i.aJ .1tf Jen.:,:c the sprc.1d .uounJ the nominal d1rc.:t1.>n of 1hc fr:ign-.c::itm~ 01:i,..._-t 111 the :uunuthal auJ polal .angles. ropcctivd). The fate of a jct fra!!JDCClt w:i:s do..,ckd .:in tl:c basis of the ratio of ns tr:1ru~cNC .wJ w:1;;1tu.iill:u momc:nu. p. /p1. If

:tn:tanip. /Pt) > R/ 1

then lhc f ragmcn t fdl outsjd,: the L-.:,nc. ,,thcn,·i.-.c 11 was conswcrcd l1l cantnbute w the m=,m:d Jc:I ch:traL"tcruitlei (.::ncrg}. momentum • ..:ompo~uon). We thus implicitly 1goorc.i the: ctT.:.:u of :in C\'Clll iml m..ignctJo.; field. 11·1ti..:h ~ the icndcu.:) 10 ~""ttP ..:,ft cll:ir~ p;.in1.:k:5 out of the ..:on,,:. Therefore. the rcsulb to be pn:scotcd arc

uud cB pq9v€S N N 7 [ [ WN35vR0 Nq0S SRNN* * <* $ d N% N_E$ X? k>0NR€ Edq5q05> hm _ ; ! M : NUo z ^ ± h z z ,

= ~ — j [ ' _ / /~ ~ ~ % / X— /= _ K h j=%jK X_ ° !~ ± ~ [ 7j / j ? j ±J Xj = h x / /' j ' XJ ' j ? j ±J Xj = [ ' XK' _ ±K /' j !~ K ^ = ~ ! ~ ^ ± = /^ W ° * 7j / ! ±_J — j ? /= /' _ / _ ±K =^ =Kj% /X> j /~ /' j =[ j j % X? J j!!jK /= ~ ± _ — _ J ? j /XK ' j W ±j% ±j=j? / ~ ? ° _ =— _ ! ± _ K / X~ ? ~ ! /' j /~ /_ 7 j / j ? j ±J ° h 4 'j j !!jK /= ~ ! _ — _ J ? j /XK ' j W _ ±K W X= K ^ = = j W X? — ~ /j W j /_ X X? /> K K ~ ? /j ] / ~ ! /' j w?j±J° B ~ [ - j /' ~ W * X? Z j K /X~ ? n hn h

B XJ h u =' ~ [ = /' j _ ; j ± _ J j ! ± _ K /X~ ? ~ ! /' j 7 j / j ? j ±J ° / ' _ / [ _= !~ ^ ? W /~ > j K ~ ? /_ X? j W X? _ 7K / E W K ' X / X_ J K ~ ? j * _= _ !^ ? K / X~ ? ~ ! /' j 7j / j ? j ±J ° h 6 K ^ =jW /[ ~ W X! !j ±j ? / K ~ ? j = X±j = h £ f 8 7 _ ? W g hch ± j = % j K / X; j o ' h 6 K _ =~ ^ = jW /[ ~ ! ± _ J — j ? /_ / X~ ? !^ ? K / X~ ? = [ ' XK' W X! ! j ±j W X? /' j ;_ ^j !~ ± /' j % _ ± _ — j /j ± 5W _ = > j !~ ±j * X f n _ ? W 5 f r h 4 ' j j ± ± ~ ± > _ ± = ~ ? /' j W _ /_ % ~ X? /= X? B XJ h u X? W XK _ /j /' j = % ±j _ W X? /' j 7j / K ~ ? /_ X? — j ? / ±j =^ /X? J ! ±~ — /' X= W j J ±j j ~ ! !±jjW ~ — h

4 ' j = j W _ / _ ='~[ / j _ / ! ~ ± 7 j / = ~ ! _ > ~ ^ / v/' k j 1 h ~ ? _ ; j ± _ J j =~— j nsNhh ~ ! /' j j ? j ±J ° [ _= K _ ± ± Xj W >° ! ± _ J — j ? /= /' _ / /±_ ; j j W ~ ^ /= XW j /' j K~ ? j h B ~ [ E j ; j ± * _ = / ' j 7j / j?j±J° X? K ±j _ =j = * /' j K ~ ? /_ X? — j ? / ±_ % XW ° X— % ±~ ; j = h B ~ ± j ? j ±J Xj = _ > ~ ; j vgQ k j 1 h /° % XK _ ° j== X' _ _ m s R ~ ! /' j j?j±J° X= ^ ? _ K EK ~ ^ ? /j W ! ~ ± [ 'j? /' j K ' ~ = j ? 7j / _ J ~ ± X/' — = _ ± K _ % % Xj W h

?^

~;5~

U n

j’

_ E !/

ms mg8s

w ? j ±7; Tkj1l

B h: h u h 4 6 _ ; K ± ^ ± ! K ^ ^ _ ? ~ ! / > K $— N j /[ ± J ' _ ] X X_ _ ? j W — /' j 7 j / X W j _ _ ^ ^ K ~ ? j ]U _ ! ^ — X X ~ _ Û / ' j $— N K ? K ±K ° h 0 K X^ z / X _ ± K

TQ /j ? ~ ± 7 X — 9 ; [ X/' x XU X z / E 8 h , Xj j ± ± ~ ± > _ ?

/ /[XXK _ X K / ' j p•]k£■p +_ /> K ± ± / ^ ! K X K _ ^ _ j XX > ° /' j K ' _ K j ^ / A / ' j

/ _ X ^ j $ : / > j ! ± _ Y ~ K K ) X X / ^ ~ !^ X^ ± /^ X_ % _ ± ^ = j / j ± X h

[

Xmc

_

~X?e

•7(E^° ;! XK1 lv hjh d 4 ' j e; 7±^ ± hP 7/ hU 7? _ X ! ^ K ^ X K ) ^ K X h _ )!/j ^ X X E z K ~ K ± ± h

[_±±h9Az (U ±^ ? ] j / hU[h%-" /'j 7jXE/XW!/WXX^ l |ZZM |E /!/K hd■» K±] XKU h ?R ~/^) [ 7? h WU _ X _ ±9 i8 7? £N e' ^ o j / K ? j ±. l v8 U oû / z E

/ Y K / X / _ / h X » — EU _ ' x # s + ■R™(] i ! # ■l c 4 ' j _ X Xl ± > ^ ? h

z9) [ 8 j /> j X % ± K ^ z XM /' j ± K — ^ X K _ X~ K 8 >° /> K [ 'K_7= £N /' j

; _ X~ j K X / / j ± ± _ E K ± h j ? ^ ^ — ^ X ^ ^ — '

4 ' j j ? j ±J ° ±j = ~ ^ /X~ ? K _ ^ = j W >° 3U’UW^’*UU„Y[ X? /' j j? j±J ° j _ ± ? j W >° % _ ± _ W j = /±_ ; j X? J ~ ^ /= _ Xj /' j K ~ ? j X= = ' ~ [ ? X? B XJ h c h B ~ ± 7 j / j? j±J Xj= ~ ! uc k j 1 * _ = ! ~ ^ ? W — /' j W j K _ ° ~ ! H N > ~ =~ ? = % ±~ W ^ K j W _ / /' j K < K N K ~ XW j ± ) w L h /' j K ~ ? /? > ^ E /X~? /~ /' j j ? j ±J ° ±j = ~ ^ /X~ ? ! ± ~ — 7j / _ J ~ ±X/' — = =^K' _ = /' ~ = j W X= K ^ = = j W ' j ±j _ — ~ ^ ? /= /~ E m s U hhh 4 ' j ±j !~ ±j * /' j ±j [ _= ? ~ K ~ — % j X? J ±j_ =~ ? /~ X? = /_ W j /j K /~ ± = — j _ =^ ±X? J ' _ W ± ~ ? = [ X/' _ % ±jK X= X~ ? > j / / j ± /' _ ? /' _ / — A' j ) w L j] % j±X— j? /= h q ~ [ j; j ±* _ = /' j j?j±J° X? K ±j _ =j = * /' j = X/^ _ /X~ ? K ' _? J j = h 4 > j 7 j / = > jK~ — j — ~ ±j _ ? W — ~ ±j K ~ XE— _ /j W _ ? W h _ = _ ±j = ^ /h ! ^ K /^ _ / X~ ? = X? /> j j? j±J ° K ~ ? /_ X? j W X? = XW j /' j 7j /EW j ! X— ? J K ~ ? j _ ± j ±jW^KjW h B ~ ± 7j /= ~ ! c ss k j 1 _ ? W ' XJ ' j ± * /' j K ~ ? /± X> ^ /X~ ? ~ ! /' j 7j / _ J ~ ± X /' — /~ /> j 7 j / j ? j ±J ° ±j =~ ^ /X~ ? X= ~ ! /' j ~ ± W j ± ~ ! m R h = — _ j ± /' _ ? /' j X? = /±^ E— j ? /_ j ? j ±J ° ±j = ~ ^ /X~ ? _ K ' Xj ; j W [ X/' _?° ' _ W ±~ ? K _ ~ ± X— j /j ± /' _ / ' _ = j ; j ± > j j? /j=/jW h 4 ' j ±j !~ ±j * _ ' XJ ' E±K = ~ ^ /X~ ? ' _ W ± ~ ? K _ ~ ±X— j /j ± [ ~ ^ W X? % ± _ K / XK j — _ j _ K ±^ K X_ W X! !j ±j ? K j !~ ± /' j % ±jK X= X~ ? [ X/' [ ' XK ' ' XJ ' Ej ? j ±J ° 7j /= K _ ? > j — j _ =^ ±j W h

mur


rolJIIC'\\·h:u too optimmx. cspccinlly for Lav.· jct cnagic:s.. At the lngh =!!ics "Ahidl :ire: the focus of our swd). jct fr-Jg:ncnts ~t a::c sllliCc:pUble to the ,iwccp1og dfo:t.t of :1 magnetic 6dd tcproell onl>· a sma!I f ra.:tioo o( the total jct cllCJID·. The dTc..-u of a ~ttc fc!J an: diicusscd in more dc1:1il in the oootc.·tt of the Eixr~ Fl.ow '.\kL'wd. in S.."L'tiL>tl 3.3.

Fi!:. -' sho"' s ~c ,l\"cr:ige fr:i.:t110n o( the jct cncr.1..~ :fult "';u found t;, be i:onuiocJ m a )Ct·

J..--rinia_g cuoc. as a fun.:u.:io of the Jct O'ICC!,,~. We ll.!>..--d t\lio .!tffcn:nt cone 'IU.::\. R = OJ .ind G.5. :cspccti\C::~. We aL..o 11>1:d t\1/o fta~men1.:Juon functions -Ahi.:h Ji:Tc::-i:d in th.: \alu.: f,lr the parameter z. as before: :r = 3 ar.'1 x = 6. TI\C crr,>r bar\ ,,n the J.tt:i puil!l.s in F:~. 4 mJ1wte the ,prcaJ 111 tb: Jet ,un:.11:ur..::11 rc:suluc~ frvm th~~ ..!C£!CC of frC-.:U'-'ffi. T~ .!.ttJ ,hu1~ tnJt for JcL., of .1::-uut ~u Ge\".

on ;l\·cra.;c ,o.>ll!C ~" .. of tl1.: .:ocr_g~. -~a,i .:ar:i...--J ::>)

fr .t!,fmc:tt1' th.:.t tr .ndk.! .la.ts.Jc the ,onc. H.i" • ,:1 ::: . .u the ,ct :::1..:q:~ u:.:rc-.bo. the ~Jntammcnt rar1.!l~ !mpr,l1 cs. F,,r cn--.:-r!::o ab,>1c 100 G.:\·. t~px:alJ~ !cu lhJU J()";, of the CDC:-!!)' Li una..;• counted f,>t .,.hc::i the ch<>= Jet al!,f.,rilhm, J:e .Jpptie.!.

IIIJ

JI\

10 ,oo

. . ..

,•11-·UJ :, 11_.u.!

IOJO

Enerr.- (GeV>

l',g. -1. Th, .1~ fr.i.:LIOn .:.( !be .J:« .m.:rg) u>Cll-"ncd <II I~

.:d~Lll! -x,~ .u A (yn...--ti&>u i.1i th,: .. ct cU!!,_Y. Raul1, .JR'

l!.m:11 1;,r ~- wid1 R-<U .&..-i Jt-uf n.., arwr hln in.Ii= the ,prcu.! ,n ~ .-..ults .;.i....,.! h, the dl~ct .:f 1~

,;iiu,e .:,/ tk fr.a.p:,a,r.ui..n fun.:n.in ~ L

146

'O .... . . ,

I ~ ~-

! .E .)) ... ... ~

-~ I~

.:

~ - 1)

·"

•,_ ri=6

u-1

, . '

· ;: R .. ::-.:Oi'. = w __ -•lJ; ----·

.. 1;1.1

f1)C"!'~:- ,t~V,

:1u·

I'.~ ! Per .:unr.r.t'Gt..un ..:I eu,t.u.:~C.. .A the WIJ CA.t.:ff'•

.... ,r.,.•.! t,.,. ~11.....:1&:" ~ .. r,..1t ,~ 1~1~ti..\,n,.1 ... ~,1~ 1 ... , t~ -~•

lo!rJ.:t~~· n-~ia.~n . .u .L JJ.A...1.in u1 :h,: !t!t ~~r~ it'-4';u~a ..ii:

~\(I~ fwl ,..t..lfO ,.,t!l J,( - \~ ~ iU-1 if - Ii~ I!•..a: ,,;flvt ~C"\.

~: th&: .pr:-~ ,n me: r.:,L...U ~.u.ac&t ~ th.: dk.:~: "' du: l"J..loe d rt.! rr~eonuL...,n tund ... )11 r2J...~:t:r :a

The el!Ctg) resolution .:.i..seJ by flu, rua11t111J m the encr~ ~ b) parudcs tr.nell~ ouu;Je the cone 1s ...bl),\D w fig. 5. For JCl cnc:i;u:s o( .:5 C,c \'. .u fo im.! u1 the .!.."Cly of "L1 b-Osor..s produced .u the c· c· collidcr LEP. ~ oontnbuu .. ,n to the cncrg, rcsoluu.10 from JCt al!1ori1hrru -.ud1 ;1ll th= .fui.:l!SllCI.! h-::r:: .:m:ounts w .. J(r' '"

Therefor::. there v.as iw .:Llmpel!in;; rc;c..)n 10 ins:all Jcta:WB rr.casunng h.JJrolli ,\ith a pn:ciii,m better th.ln tlut in •he LEP c.,.p..-runc:cu. Howe\et. :u the =rg) increases. the m1Uuon ch.tn~ 11>e jcu bc,;ome more: .lJl.i more coUim.11,:J J.nd. .15 a result. t!uctuations in the energy contamcd truide the jct.Jctimn.g cocc a!e: reduced. For jCli or 500 GcV .inJ higl---r. ti.Jc contnbution of th.-: jct alg(lrithm to th.-: jct cn~·y rcroluuon JS of the order of I~-:.. ~fl"lllller than the w.strumcntal cncr~ rc:solutio11 :.clu~-i:d 1uth an) hadron ~--.i.lori.'tlctcr that has e,·cr be.:n tcstc:t!. Therefore. a biiPt-rcroluu,on ?udron cakmm..."tcr would Ul pncr.i.::;: mal.: ..1 .:nicul Jiffcn:nu: for ti.Jc precision wtth w hicll h1gl.J--,::-i.:r;;y jeu can be a:.::uurcd.

c pq)9<<* < N =Np [ W<N5WN010 [N*d,S5*N1 L Q < : N Nv S > _ / }>N1N5< x±7K~±Kx } *)W <j°M]j< [-J*['- uuu

4 X = X= X ^ = /±_ /j W X? B XJ h r h [ ' XK ' =' ~ [ = /' j K ~ K /? > ^ / /~ ? ! ± ~ — /> K N X ± ± j W ^ K X> j N !^ K /^ _ /X~ ? = !~ ± _ K ~ ? j [ X/' £ f shn _ = _ !^ ? K /X~ ? ~ ! /' j 7j / j?j±J° * [ ' XK' e= % ~ //j W ' j ±j ~ ? _ =K_ j X? j _ ± X? w < A< T /' j =~ XW K^ ±; j 'h B ~ ± K ~ — % _ ± X= ~ ? * /' j — j _ =^ ±j W ' _ W ±~ ? XK j?j±J° ± j = ~ ^ /X~ ? = _ ±j J X;j? !~ ± /[ ~ j ] % j ± X— j ? /= _ / /'j !^ /^ ± j ) q g _ / g ) 0 P Tx 4 ) x Z Trm _ ? W g - Z DpM _ ? W 4~± /' j Z L x g x ) K _ ~ ±X— j /j ± DnV* [ ' XK' K ^ ±±j ? /° > ~ W = /' j [ ~ ±W ±j K ~ ±W X? /j ±— = ~ ! ' _ W ±~ ? XK j?j±J° ±j = ~ ^ /X~ ? h 4 ' j _ //j ± K _ ~ ± X— j /j ± [ ~ ^ W ±j % ±j = j ? / _ = XJ ? X!XK_? / _ W ; _ ? /_ J j XK ~ — % _ ±j W /~ /' j ) q g ~ ? j=' !~ ± /> j W j /j K /X~ ? ~ ! 7j / = [ X/' j?j±J Xj= _ > ~ ; j vgQ k j 1 h > ^ / _ / ~[ j± j ? j ±J Xj = /' j * ^ _ X/° ~ ! /' j — j _ =^ ±j — j ? /= X= W ~ — X? _ /j W >° /' j 7j / _ J ~ ±X/' — h

v/ W X~ ^ W >j j — % ' _ =X\ j W /' _ / X? /' X= _ ? _ ° =X= [ K '_;j W j X> j ±_ /j ° XJ ? ~ ±jW /' j j !!j K /= ~ ! % _ ± _ W j = /' _ / W ~ ? ~ / > j X~ K j /~ /' j ! ± _ J — j ? /X? J ~ > 7j K / > ^ / — XJ ±_ /j X? /~ /' j 7j /EW j !X? X? J K~ X/K h Q ! K ~ ^ ±=j * /'j=j j!!jK/= /j ? W /~ j ] /j ? W /' j X— % ~ ± /_ ? K j ~ ! /> j K ~ ? /± X> ^ / X~ ? = ~ ! /' j 7j / _ J ~ ±X/' — /~ /' j 7j / j?j±J° ±j =~ ^ /X~ ? h 4 'j° _ ±j j] /±j— j° W j % j ? W j ? / ~ ? /' j /° % j ~ ! j ] % j ± X— j ? / Xj U KU ~ ± % % K ~ XW j ±= * ']jW /_ ±J j / ±; % K ±X— K XAhX= _ ? W _ =~ ~ ? ! 7 j /~ ± = ;^K' _l /' j ^ — X?~=X/° _ ? W /' j 9 X? j— _ /XK ±j J _ X? ^ ? W j ± = /^W° h

!K?j±J° T k j 1 v # E

z■ 38“ h " b6 Cn ’-

zQ

c

b

E# !iwB XJ xh 4 1 > = W ± ~ ? ^ e j? j±J ° A ±j ^ 8 X? U TX= hZ♦ /' ± j j ^ W ^ ! ^ ? K XK ± ]y*yH•’c■£> /' j p’p^■]C"c£>»Hp ph pDk■Ypy"p¥*" k£^k P->, p■ # O F _ /' j j j ? j ±J ° ? _ ^ ' ^ _ = ? h = = ] ! ^ ? _ ^ = ? ^ / j ? j ±J °

4 ' j =j ’6V2;^K6H 2U2Y^ j ! !j K /= _ ± j _ ±J j=/ X? /> j ' Xj' EX7 ±jJ X~?= ~ ! ' XJ ' E ^ — X? ~ = X/° % % K ~ XW j ± j] % j ± X— j ? /= h =^ K' _ = /' ~ = j % _ ? ? j W !~ ± /' j !^ /^ ± j ) q g _ / g ) 0 P h [ ' j ±j j ; j ±° X? /j ±j = /X? J j ; j ? / X= _ K K ~ — % _ ? Xj W >° # a c ~ /' j ± j ; j ? /= /_ 9 X? J % _ K j X? /' j =_ — j > ^ ? K' K ±~ = = X? J h Q ? /' j ~ /' j ± ' _ ? W * X? /^ J > EK? K ±J ° 2&2& K ~ XW j ±= W X= /^ ±> _ ? K j = ~ ! /' X= /° % j _ ± j ? ~ / ;j±° X— % ~ ± /_ ? / h 4 ' j K ~ ? K ^ = X~ ? = W j ± X; j W !±~— BXJ h r _ ± K /' ^ = % ± X— _ ± X° ;_XW !~ ± /' j _ / /j ± /° % j ~ ! j ] % j ± X— j ? /= h

nh ,Xj j?j±J° qX— —j/'~W

RW=W \Y2 —q’^b UÛ2q

v? /' j % ±j; X~ ^ = = j K / X~ ? * [ j ' _ ; j ='~[ ? /' _ / _ = /' j ' XJ' Ej?j±J° ! ± ~ ? / Xj ± ~ ! %^ ±^ KzK %' ° =XK= X= % ^ = ' j W /~ ' XJ'j± _ ? W ' XJ ' j ± ;_ ^j=* ' XJ ' E±K=~ ^ E ^ ~ _ — j _ =^ ±j — j ? /= ~ ! ! ± _ J — j ? /X? J ' _ W ±~ ? XK K ~ ? E= /X /^ j ? /= =^K' _ = * ^ _ ± 9 = * _ ? / X E* ^ _ ±9 = * W X* ^ _ ±9 = _ ? W J ^ ~ ? = >jK~— j= X? K ±j _ = X? J ° %~ ==X> j * = X?Kj /' j X— X/_ /X~ ? = X— % ~ =j W >° °j/EWj!X? X?J _ J ~ ± X/' — = > j K~ — j j;= ~ ! _ ? X= =^ j h 4 ' j ±j !~ ±j * /' j X? /± X? = XK * ^ _ X/Xj = ~ ! /' j X? = / ± ^ — j ? /= [ X/' [ 'XK' /' j 7j / j? j ±J Xj = _ ±j >jX?J — j _ = ^ ±j W > j K~ — j /' j W j /j ±— X? EX?J !_ K /~ ± X? /'^= ±j = % j K /h

4 'j /jK' ? X* ^ j= / ' _ / ' _ ; j > jj? ^ =jW ^ ? /X ? ~ [ X? K _ ~ ± X— j /±° — _9j ' XJ ' E ±K = ~ ^ ! X~ ? K— _ ? W ' _ W ± ~ K =' ~ [ j ± W j /j K /X~ ? — ^ /^ _ ° K ] W ^ ] X; K % ±~ % ~ = X/ X~ ? =D m 'h q XJ ' E±K] ~ ^ ^ ~ ? ' _ W ±~ ? XK =' ~ [ j± — j _ =^ ±j E— j ? /= ±j * ^ X±j K ~ — % j ? = _ / X? J K _ ~ ±X— j /j ±= h x ? W K ~ — % j ? =_ /X~ ? TXhj h j * ^ _ K _ ~ ± X— j /j ± ±j =% ~ ? =j /~ /' j K— _ ? W ? ~ ~ Ej — K ~ — % ~ ? j ? /= ~ ! ' _ W ± ~ K =' ~ [ j ±= h 2*VU f mhs ' X= ~ ? ° _K' Xj; jW X? =_— % X? J K _ ~ ± X— j /j ±= [ X/' _ ;j±° =— _ =_— % X? J ! ±_ K /X~ ? * j hJ hh a hn R X? j _ W A% _ =? K E; K — /X) X/~ ± = /±^ K /^ ±j=h Q ? /' j ~ /' j ± ' _ ? W * ' XJ ' E ± K = ~ ^ / X~ ? K — ='~[ j± W j /j K E/ X~ ? ±j * ^ X/j = _ ? X? = X ±^ — j ? / [ X/' _ ;j±° ' ± J j = _ — % X? J !±_K /X~ ? h 4 ' j H w 8 Z g ~ _ > ~ ±_ /X~ ? * [ ' XK' K^ ±±j? /° ~ % j ±_ /j = /' j ' XJ ' K=/E±j; ~ ^ /X~ ? ' _ W ± ~ ? K _ ~ ±X— j /j ± X? /> j [ ~ ±W mbV* %_°= _ % ±XK j ! ~ ± /' _ / X? /' j ! ~ ± — ~ ! _ ±_ /' j ± — j W X~ K ±j % j ±!~ ±— _ ? K j !~ ± K — = ' ~ [ j ± W j /j K /X~ ? e *[k # <’']DkW g _ ~ ± X— j /j ±= = ^ K ' _ = /> j ~?j= /' _ / [X > j ^ =jW X? /' j ) q g j ] % j ± X— j ? /= j— % ' _=X\j j ] Kj j ? / j j K /±~ — _ J ? j /XK ±j =~ ^ /X~ ? * _ / /' j j] % j? =j ~ ! ' _ W ±~ ? XK ±j = ~ ^ /X~ ? * _ = X= X^ = /±_ /j W X? B Xj h r h

mup


r.ili iJ illustr:1tcd in Fig. 6. which sru:nu thc: contnbution fr-3m the "irreducibli: .. t!uct~tiocu for a t."ODC with R = 0.3 as a funcW!l .:,f the jct energy. "'hicb is plotted h..:rc on a iC3k linear in

£-: ~ (the rnl:J curi.c). For compimson. the measured hadrooic c:ocrgy rc:sc>luuons arc ~i\'al

for two c:xpc:nmc:it,; .lt tbc fuum: LHC at Cl:.RN tATL-\S (61 .i.eJ C\lS [7{) anJ for the SPACAL c:alunmc:cr [l!J. wbr.ch cUI?altly b&Jlds thc '4·orld r.xorJ Ill t.:r:ns of !1.ldrvn.ic =!':::') rc:!>ofoti,,11. The !Jttcr i:alon:ncrcr \\J•J.!.! rc;ircs..--nr J si-;n:fo.:ant .1J~am.1~c: 1comparo.i to thc LHC on.:sJ for the ... 'c1.:i;u.-,n of )C"...; ·,\Ith cnc:-~1es J.00\C: l(NJ Ge\'. but at lo\\er cnct!:J:ei the: ,i ualit)· of the m.:.u1.,rciru:nl!i 1s o.!omm.ucJ hy th.: JC! J.!~on!.!'.m.

It .J:,,t:IJ be ernpha.,i.11:J tlut in this Jr.alj\is "'e !1.1.,c: Jd1b.:ratcl~ :;;n..irc:J the effa:t, .,r p-.ut1.:Ics th.it Jo nu: bc:i.>c~ w the fr:igmenung obJcct bur nu;;r:1:c 1:llu the JCt-<lc:imng c,,:1-.:. Of .:,•ur;c_ thc,,c c!Tc-.-t., 1c:1J t..> c:.\:.:llJ 1.1!,c: imp,.:,r:.:u•Ao-c oi the cocmb.:t:nr.s. ,,:- :t.;: Jc! .1I!1"ntt.:n to the JC! .:i1cr;!~· ro.c,!ution. The) .1:= e.,1:cmd) JcpcnJ.:,11 on the t) pc of c.,pcn:n<!llt I c-e- ur pp collid.:n. t..\CJ 1.1.ri;.:1 :.\p,.=:rr..::u~I .1nJ .100 ~,n f .. 11:1,,r.; ,uch J., the luntllll1'i.lt) a.1d 1:ic k.1ucnu1;.: re;;:..,n 1..nL!cr ,tu.!~.

ll .,, •11 , .. , 11tr: ... !II I '•.

• 015 :ir,-luJ I \• ' \ -= .,n ...... , ""'·"" I • il"\C\I

I ' - ,inMr..-1111111fri \ ' ' ~ ;ii \

= ' i \ s ... \ ~ .

\ ;,., \

"' \ !j ::1 JII

: l ' '

~-

~ .~ •I.JI QJ~ 0.1-0 l)Jlj 0

-11/t F •• r,. Th., b;,J,..,n..: fflcer:, ...,._,...,._," .;t tbr<r ~ .;...,, • an.I 1fr w•r.b111~ ,,i ~ jet,ldiAUI! .-.- •ub R - o_; tu lbc _-c:1 <:nc:r~J .....,.,.la) ... ;,,>~ (IM>:li.>A .. .- ODCl~J

1-17

111

Tlu:r 1111tk1il'illl} er~ effects arc ~ in the ~h-11 ccgion1 of high-ll1minosit~ pp .:ol.lidcr c.,pcrimcnu. such :u tho,;e planned for the iuturc LHC at C!;R.'I. wberc .:',cry inta"cuin! c\Clll :.s :i ... -compamctl by - .!~ otha c,·c:1~ Ul1n;; pl.i.x i!l the tame bunch c;rossiJl!t. On the l.ltllcr haoo.. 111

lllgh-cncrgJ c-c- colliJ.:rs J1St:1rbanccs of this t~pc .uc n,,t \-Cry imp.Jrtanr. The -:..indu~i,">tU derncJ fro:n Fig. 6 arc thus pr:nunl~ \~J for the la:rcr t~p: ,,f C.'1.('C!:mcnts.

ln th.:: prc\:,H1s ~twn. '-C ha,·c ,hown :11a1 i,.

the h1~h..:ncrgy fror.ti<r <>f ramdc ph:,-s.J~ ts

rJ.:ihcl.! :~> h1~hcr J1~J hi;;!'h.:r \a~uc:'-. hi;;h-rc-x_,!uU.l!l r.~.1«uen:c:-nt:. uf fr .. ~cnun~ ludrnnu: .. -ou,utucr.i.i ,ud1 .is -i~ru anu~.wrl..,. J;qu.1:I..., aoJ :1la,1n, bct..um.:,. 111.:rc-.i~in;;J:, p.,~,1h!.;:. sm.:c the lmutat1<>n1 1m!)Os.:<l b~- )Ct..:Crirung :tl~i.>nL'u-..!i l">i.'\:,~rnc I.:\., or .111 :s,1.;e. Therefore. the m:nn,1.: c,a..il!t:a ,)f the 1:1...uu:ncr.~ .,.:th \\h:..:.n th.: J~ cncrgiCi .uc bong tnc:lllured become the dc:.:rmm-1.'l!! f.tctur m th:s f;:!>P,:.:l.

The ta;;hniqua that !W\O: bc:cn :ucJ until 001,· Ill

.:a!.,nmcrry malt.:: high-rcsoluuon cm JnJ lwJrnc u=u-..cr Jc:o.:t.iun mutua.U} a.d~,c prop1.nuiucs [J). H1llh-rouluwn had:01111: !ilt.>'4ct rrx:asUiemc::u.s require compensating cal1.m.mc1cn. AnJ ..:i.>mpcn.auon (Le. cqua.l c-.1lorimc<..c:r rc>P<J:UC 10

the cm :md noo-em oomponcnu of ludroc dl,,v.cl'l. .-/I,= 1.0) is llnly achic\-cd tn \amp!ini; cloruncrcn \\oith .1 \CC} small SJroplillg frat."twn. e.g .. 2.J·-~ in lcad,p.1.unc-s.:inull.itor ru-ucrurl:.'. On the .:>th..-r lwnd. hi;;.'t-r.:wlut1"n cm iho111cr Jcrccuon TC4um:s an instromcnt 1\1th a very large i3lllpiing fraction. Tb.: ZEUS CoU.-ibor:uion. which currcitl) opcr.11.::s the h.1ghcst-fc:iolution ba<iron c:uorimctcr iu the ~-odd [CJJ. pay~ a pric-c for that in the form of a rather m.:d1ocn: pcrfonnanu:: for c:m ,lhowcr Jctccuo11: t1 / £ = I&".,~; ·./E. Ca!or=tCt'$ such :u the ones th.ll will be uscJ iu the LHC c.,pcrimcnl!i c:mpl:.J.'ilJC c.udknt ela:trom:igcctic =lution. at the e.xpcn.,;,: of hadroru.: r=lution. as i5 1Uustr.1tN m 1:-"'ig. 6.

c p , R * =N X ! X N MR—N—_0 ' ± — _ ~ _ ? W 8 ± ? 6 X u / z 5 / / / ± X I NRq0N} } E ™ < X 9 ] < N n e . V Z [*d

_ ! ^ /^ ± j j ] % j ± X— j ? /= * j hJ hh _ / _ % ±~ % ~ = j W X?j_± K<K< K ~ XW j ± X? /' j s hc #m 4 K 1 ±_ ? J j * [ ' XK ' [ _= ±j Kj? /I' W j !X? j W _ = /' j — ~ = / W j = X± _ > j !^ /^ ±j — _ K ' X? j !~ ± % _ ± / X W K % ' ° =XK= ±j = j _ ±K ' D m s ’ h ~ ? j ?XI [ _ ? / / ~ > j _ > j / ~ — j _ =^ ±j *U^ K ~ ? = / X /^ j ? /= ~ ! — _ //j ± [ X/' ±j = ~ ^ /X~ ? = _ / /' j m R vK=j h 4/j * ^ j = / X~ ? _ ' ~ [ /' _ / K~ ? > j _K' Xj; j W h

Q ? j ~ ! /' j =~ ) /X~ ? = % ^ ±= ^ j W X? /' X= K~ ? /j] / X? ; ~ /= j = /' j =~ Ej_8 KW kY2;4G fV„0 w2^x„m Aw B - 'h X? [ ' XK' /' j X? !~ ±— _ /X~ ? !±~ — /' j K _ ~ ±X— j /j ± =° =/j— X= K ~ — > — K W [ X/' /' _ / ! ±~ — _ ? ^ % = /±j _— /±_ K 9 j ± =l = /j— h 4 ' j — ~ — K ? /z ~ ! /' j K ' _ ±J j W 7j/ ! ± _ J — j ? /= * — j _ =^ ±j W [ X/' ' XJ ' % ±j K X= X~ ? >° /'j — _ J ? j /XK / ±_ K 9 X? J =° =/j — * =K±] j _ = _ ! X±= /E~ ±W j ± j = /X— _ /j ~ ! /' j 7 j / j ? j ±J ° h 4 ' j K _ ~ ± X— j /j ± =XJ?_= _ ±K ^ = jW / ~ ~ > /_ X? = j K ~ ? W E~ ±W j ± K ~ ± ±j K /X~ ? = /~ /' _ / j? j±J ° * K _ ^ = j W >° /' j ? j ^ /±_ 7j / K ~ — % ~ ? j ? / !°=h ( N= _ ? W ? j ^ /±~ ? = ' h 6 X/' — j /' ~ W = ~ ! / X / = /°%j* = j; j ±_ ) ) L j ] % j ± X— j ? /= X— % ±~ ; jW /' j ± j = ~ ^ ^ ~ _ ~ ! 7j /= ! ± ~ — i E W j K _ ° ! ±~ — E v A I * /~ E r A h h 6 j ' _ =K = /^ W Xj W //j — j ± X/= ~ ! =^K' — j /' ~ W = * _ ? W X? % _ ± / XK ^ _ ± /' j j ? j±J ° W j % j ? W j ? K j ~ ! /' j =j — j±X/= * [ X/' /' j = _ — j - ~ ? /j g _ ± ~ % ±~ J ±_ — /' _ / [ _= ^=jW /~ X? ; j = / XJ _ /j /' j K ~ ? /± X> ^ / X~ ? = ~ ! 7j / _ J ~ ± X /' — = /~ /' j 7j / j ? j ±J ° ±j = ~ ^ /X~ ? TZ jK /X~ ? haW

U hW h1~ 2*V„;’Y2^23

4 ' j w ? j ±J ° 0 ~ [ - j /' ~ W j ] % ~ X/= /' j !_ K / /' _ / /' j K ' _ ± J j W ! ± _ J — j ? /= ~ ! 7j /= K _ ? > j — j _ =^ ±j W — ^ K ' — ~ ± j % ±jKX=j° [ X/' _ / ±_ K 9 j ± /' _ ? [ X/' _

K _ ~ ± X— j /j ± h q ~ [ j; j ±* /' j K _ ~ ± X— j /j ± X? !~ ± — _ /X~ ? X= = /X ? j jW jW /~ _ K K ~ ^ ? / ! ~ ± W Xj K ~ ? /± X> ^ / X~ ? = ~ ! ? j ^ / ± _ % _ ±/XK j =* — _ X? ° ; = ! ± ~ — X!U W j K_ ° h > ^ / _ = ~ 9 = = _ ? W j K^ /± ~K] h v? /' j _ > =j ? K j ~ ! K _ ~ ± X— j /j ± X? !~ ± — _ /X~ ? * > _ =j W ~ ? / ± _ K 9 j ± X? !~ ±— _ /X~ ? _ ~ ? j * /' j 7j / ±j =~ ^ /X~ ? [ ~ ^ W > j W j /j ±— X? j W > ° /' j ! ^ K /^ _ / X~ ? = X? /' j ! ± _ K / X~ ? ~ ! /' j /~ /_ 7j / j? j ±J ° /' _ / X= K _ ± ± Xj W >° /' j K ' _ ± J j W !±_J — j ? /= h 4 _ > j v X= /= /' j =j ! ^ K /^ _ /X~ ? = !~ ± 7 j / j? j ±J Xj = ±_ ? J X? J ! ±~ — ms k j 1 /~ v 4 K1 h ! ~ ± = X— ^ _ /j W 7j /= [ X/' X f n _ ? W X f r h ±j=%jK /X;j ° h

4 ' j _ ; j ±_ J j j? j±J ° K _ ± ± Xj W >° /' j K ' _ ±J j W 7j / ! ± _ J — j ? /= X= ■ ~ ! /' j 7j / j ? j ±J ° h q ~ [ j; j ±* //j K ; j ? /E /~ EK ; K ? / ! ^ K /^ _ /X~ ? = _ ± j _ ±J j * /' j /!?++ _ — ~ ^ ? /= /~ z s R ~ ! /' j _ ; j ±_ J j ;_ ^ j ! ~ ± A v n 7j / = _ ? W !~ ± 5 f r h UYm2!2Ym2Y^ „3 bU 2 V2^ 2^^2;GG Q ? j —_° [ ~ ? W j ± [ '° /' j=j ! ^ K /^ _ / X~ ? I W ~ ? ~ / > jK~ — j = — _ j ± _ / ' XJ ' j ± j?j±J Xj=* J X; j? /' j !_K / /' _ / X' K Y’6)2; ~ ! 7j / ! ±_ J — j ? /= h? K±j^ =K] h 4 ' j ±j _ =~ ? !~ ± /' X= /= /' _ / /' j ~ > =j±;jW X? K ±j _ =j X? — ^ /X% XK X/° /= ^ ? X* ^ j ° K _ ^ = j W >° /' j _ W W X / X~ ? ~ ! — ~ ±j („3^ % _ ±/XK j = h 4 ' j >^9* ~ ! /' j 7j / j ? j ±J ° X= X? ; _ ± X_ > ° K _ ± ± Xj W >° _ =— _ ? ^ — > j ± ~ ! /' j — ~ = / j ? j ±J j /XK % _ ±/XK j = X K ! 4 XJh n'h 4 ' X= — j _ ? = /' _ / /' j !±_ K /X~ ? ~ ! /' j 7 j / j?j±J° K _ ± ± Xj W >° K ' _ ± J j W % _ ±^ W K = X= = /±~ ? J ° W j % j ? W j ? / ~ ? /' j j ] /j ? / /~ [ 'XK' /' j =j % _ ± /XK j = % _ ± /XK X% _ /j X? /' j ® j _ W X? J AA K ~ — % ~ ? j ? / ~ ! /' j 7j / h 4 ' j ±j !~ ±j * /' j K ; K? /E X~ EK ; j ? / ! ^ K /^ _ / X~ ? = X? /' X= ! ± _ K / X~ ? _ ±j )_±Jj _ ? W W ~ Y„^ = XJ ? X!XK _? /° X— % ±~ ; j [ X/' j ? j ±J ° h

4 _ > j /

4>j ]X/_ ——/^° K ~ X/^ Xg >° /'j E8~X_h= ' + J ^ = + ^ _ U / X ^ — /'j W ^ K /^ ^ ^ 7/^ h _ /' ^ j?j±J° h ± X _±j )_ X ? X ~ ± $—N K_K±JXj= ±__Xjh?[ !±~— ms vvvQ kj1 0 _ ^ /= _ X ± % = ± ~ / ~ ± /[~ j_ X/! ±=] ;_^j= ~ ! / ' j /±__—j]8_9- !^jj/^=_ %_±_— j/j± _

» ■ y*y*]D ”rks p p * G < * "■

6 p£Hcy■7 ps^hcc£*p■ — £ c p£ ■p^ c T 6a ]’k■p "* ""¥ y * £ ">£i■mr■mnm ['Z*'®

>pj GOCF u GG ? 2 n'y Ge V - > c 9 gFO pTU)]A*iG 6 CV ' ■ r j T v

2■m' Y V * F 1 C 1 V " ■" ■] FV*e .. 1ZWc - m ] 1 ^ - e^C; ¥ 9 G p ^ ; p p),� 'NBu p r * 1 G C1 C *�))� TFCe j < 'eOO eO F j “ v

U<]<Z}< eOCe 6u M*>(pj

mut


l,!

111 future apcnmcnts. e.g .• .:lt .1 proposed l:ru:ar c-c- coUiJcr in the 0.5-1 TcV r.ul!:,'C. 'llllbii:h \U\

ra:cnll) dcfwc:J a:s the IIll)St dcsirab!,: f u.r.wc l!Llducc for parudc pbyuo rcsc:ucll [ IO). oru: v.ill want to be able: to 1nc:asurc ull co!Ul1tucau of rruncr ~ ith n:solutions at the: I•. lc-,cl. The quc:.-uoa c. bow th.it can be .1.:.b!C\·cd..

One of 1:1.: sol1.Lions pursued ill th!.S c,:mtc::\t

imoln:s the •LKaU.:d /:ro!r!J.1' Ffuw MetiwJ(EF:'.(). in I\ bx:n the inforrnataon from the .:awrimcter ,iy,tem is .:::.1r.1bu1ed 1u1h iliJt from an :ipsu-c-.im trJd.er s} ,1c:m. 11-.c momcnw of the cb:i.ri,-cJ Jel

frJ!,!me:tt,.. nl<:"Jsurcd wi:h hi~ pr.:cisi.1n b~ the: nw;;netJL trJ,;kin;; "')~em. s.:r,.c a!i .1 first-.!rdcr .:stiD111te of :tc: jet energy. The c-.1.I.:,riCXti:r ~1~nai... .m: u.-..--d t.> obwin 'IC..:Oo<l-orJ.:r .:LM':'cctioru :o thJt cneri;y. ~ui,a! b~ 1hc ncutrJI JC! u,mponcnt I:,,. K''s anJ ncutto:u). With m.:1.t:.1'1, of '.t.t, 1~~,c1cr:1l LEP c.ti=cnrncnu :mpro,C\1 th.: rc..:1l'.1U0:1. -,f Je"J from /.-d.::c;1} fr-,m ~ 1:0'.', to ~ .,,.,_ We

!IJ\C ,tuJic:J 1hc men:.~ oi ~h mc1ho<l.i . .u!d in pcirucul.:lr the energy o.!.:-;:,cndeil'-'C of t~ re~!ls. \\ith the ,;am,: ~l.>ntc C.u!o proi;r.:un th.it \\as w.:J Ill ll\\C'.\:Jg:llc !he c.:intnbu:1.,ns of jct .:ilg,1rithm, t,) the jc? c:tcri;~ ~=lutuln (Section ~l-

J :!. .Vr.J culurutir!Cd

The Enc:r;:_:, Fluw \lc:thL"ld c:tploits t.'1e f~t that the dt:Lrgcli fr.i!:rncm..i of JCU can l:c m=urcli much more prix:z:;cl:, -.1;11h J tnd::r th.in ,utll .1

T •blc t

.:::uonmcter. Ho~cvc:r. the t.':llor.mcta info~tion is ,ull nccdal :-1 account for me mntribution.'I ,lf neutr.1.I p:in1dcs. maioly ·,,s from tr.,. ..!o:a~. but .Jlsu K0 s an.! c.eutr~ In the :lb,;cnc-c -,f calorimeter infornwuon. based on ttadcr mforrnati»n alone. the jct rcsoluti.in would be Jctcrmined by the 11.i.::tuar.:ons m the fr.i.:t~ of the tDtal Jet c:i.::r;;-J th.it is carricJ b~· the durgc:J fr:ii;mcnu_ Tabt..: I fnlli thc:sc tluc:1uarioru fnr jct cncrgil:\ r:in!:illl: from 10 Gc:V ti> I Tc:V, for simulated jC"..,. ..-.i1h :r = J and :: = 6. ropc:ct1,·d~·-

Tbc ;i \ cr.i gc cncr-~ c-.1rricd by the cbugt=J Jet fra!::'ll?a:ti is ~ oi thc j.:t c11er,;~. lhmc·.cr. the C\"Cnt·tll~\ent fl•J<:::i:auocs a:e large. t1tc r,,_

..unount:. 10 JO~~ of the :1,-cr.1;.e va.:uc for :: ;:. 3 jc:ts anJ 1..;•. for :r: = 6. vuk~n.J.,,te u_f cl1t' .'er en<ryy. O:ic m.a ~ ~\ondcr \\ h~ thc:-;c t!:i~t aat:<llu Ju n~,: ~~~me ,m.1:kr ..tt htt!hc-r c:1.:-:"gio. ~!-.-en the fa.:~ tha.~ the l'l:.,ml•,·r of Jct fr:.;;mcc:, .n.:rC'J.:i....,.. The rcis.,n for thi.~ ti t.'ut :be .:il:>-cr..:J ir..cre-,1.;c 1:1 mu!1ipb:11~ t, umL{ud~ G1u,,.:J b~ tr..: JJ.!!11 ... ,n ,)f more .1u.f1 p:irtide!>. The bi.ll,. uf the jc: encrg:, l!i ln\.lllaoly c:uncd b~ .1 ~mall numb::: or the mo~t .:ncr~lii: pam.:b (..:i. Fig. 3L This m=-• that ti:.: tb..::iou .>f the Jct c:1.:r~ c.irric:J b~ ..:h.ugcd ;xu-udcs ti itrnngly ~den: un the cucnt tu ..-.hi..:!: 1:i.:s.:: parcdo part:.::patc in the "'lcaJin{" .:,,mpuocnt .1f the Jcl. Thc:n:fo1c:. the e\'Clt-lll-C\!ffl lli.:..'1LUliOll!I In this fr.;.:1e.,n .uc Ul)!C anJ do ,i,u ugnsti.::a:11l:, 1mpro~c ~!Ill cnc:rg:,.

Tbc 1uul .:t>«~? =n.:o! b)o the -~"'11,~I> .,,- _,<t• .ui.l 1he du.:sw.iwn, ,n 1hu """"l!) i.r_; E._1 .._,. L11"'1 iur Ff o:Qc<~

r..,.!•~ fr..c: ,ll :i:ou Gc-Y R.....tt, .II'<'~'"° t.H n,., .:J{c:r- ,.Su,:, ..,j 111,: lr•!'=:.!illhMI (uo..-..- pu:u11crcr,

kt C""'r'!'Y ({,,:\' ! l - l l -11

l."1:w-;aj fr.:!IJlCDU l-1a.::uw1•~• (-.. J 0wr!<d ir~!""'"" fl~tu.in..,cu I •:.J

tu c..:U:!.,:,i j(.U 11~3:ltiil ~:. l .!O tl.!:-ltJ Ho ll~:L:' ~.&.~

JO 1-i.i :o.U ~-0 ~=4.j'J .. ' -··-,ll) .:r..5:'i.111 .lifJ.O .!t..'l:1).-lt> =~-" 51) ll.4:11!0 loll.O ll.5:11. ll) ~: . .:!

tt!f) Clli.11:;tof.~ }0.-l M.t>: t6.J ~j_J

.!Cti ?ll=.Wl :;u.: Ill :l!.O ~.: I )I~) .?l)):!ofK ~-'1 ::W:.U.J .=:.1 -IA~) ~=ril) 4 -~-.t ~=IS,l..'. :!.:.:? !00 .H.?:ol'}~ Jiu.I ll.'.:;!t)_j ' . . -·--

:L~;tl t.1>l::Ot llJ.l u.S:\1,1) .. ' -·-·

1-18

JW d’^)’Y 2^ %(U 3 h1 _ _ W X^ ± V* 5V;0 Y * ^V( ’YD DD2Û’qx UY D^^d:K;mU hd udzVhA mmn

x = _ ? _ = XW j * [j — j ? /X~ ? /' _ / / > K = _ [ > = ? j Kj ==_ ±X° _ % % Xj = !~ ± /' j K ; K ? /E /~ Ej ; j ? / ! ^ K /^ _ E/ X~ ? = X? /' j ! ± _ K /X~ ? ~ ! W K K / ±~ — _ J ? K / XK _ ° X? /j ± E_ K / X? J % _ ±/XK j = T— _ X? ° Y}(aW 4 ' j =j ! ^ K /^ _ /X~ ? = _] j ±j = % ~ ? = X> j !~ ± /' j % ~ ~ ± 7j / j ? j ±J ° ±j = ~ ^ /X~ ? ~ ! ? ~ ? EK ~ — % j ? = _ /X? J K ~ ~ ±X— j /j ±= * j =% j K X_ ° _ / ' XJ ' j?j±J° D m zh = X? Kj /' j ±j = % ~ ? = j ~ ! =^ K' K _ ~ ± X— j /j ±= X= ^ =^ _ ° K~ ? =XW j ±_ > ° _ ± J j ± !~ ± K— =' ~ [ j ±= /' _ ? !~ ± ? ~ ? EK — ~? j=h

v? /' j _ > = j ? K j ~ ! _ K _ ~ ±X— j /j ± * ~ ± ] = ' ~ ^ W /' j ±j !~ ±j ? ~ / j ] % j K / /~ > j _> j /~ — j _ = ^ ±j 7j / j? j±J ° ±j = ~ ^ /X~ ? = > j //j ± /' _ ? a c En s ® ^ ~ ? /> K > _ = X= ~ ! / ± _ W j ± X? !~ ± — _ / X~ ? _ ~ ? j * ^± ^ ? X 2Y2;4GW x ? W = X? K j /' j K ~ ? /± X> ^ / X~ ? = ~ ! = ' ~ [ j ± X? J K ' _ ±J j W % _ ±/XK j = /~ /' j K _ ~ ± X— j /j ± = XJ ? _ = > _ = j /~ >j W X= K ~ ^ ? /j W % ±~ % j ±° !~ ± /> j w B - /~ [ ~±9h* /' j * ^ _ X /° ~ ! /' j K _ ~ ± X— j /j ± X? !~ ± — _ / X~ ? X= X? % ±_ K /XK j X— % ~ ± /_ ? / h

> DW wW’^Y2Yb 3U2Vm 2332b^(

4 ' j % ±~ % ~ ? j ? /= ~ ! /X?U — j /' ~ W K _ X— /' _ / /' j 9 j ° /~ X/= =^KKj== X? _ ) — K ^ ±Eg ~ Xz j ± j ] % j ± X— j ? / X= W j /j ±— X? j W >° /' j ^[;*Y’V’;’K ~ ! /' j W j /j K /~ ± h x ' XJ ' J ±_ ? ^ _ ± X /° [ ~ ^ W — _ 9 j X / % ~ = = X> j /~ ±j K ~ J ? X\ j _ ? W j X— X? _ /j _ K ~ ? / ± X> ^ / X~ ? = ~ ! /' j K ' _ ± J j W % _ ± /XK j = /~ /' j ~ ; j ±_ K _ ~ ± X— j /j ± = XJ ? _ h 4 ' j ±j — _ X? X? J K _ ~ ± X— j /j ± =XJ?_ K ~ ^ W /' j ? >j _ / / ± X> ^ /j W /~ /> j ? j ^ / ± _ 7j / K ~ — % ~ ? j ? /= DI vzh

q ~ [ j ; j ± * / ' j * ^ j = /X~ ? _ ± X= j = [ ' j /' j ± /' j 7 j / ! ± _ J — j ? /= * > ° /' j /X— j /' j° ±j _ K' /' j !±~ ? / !_ K j ~ ! /> j K _ ~ ± X— j /j ± * _ ±j =^ !!XK Xj? /° =j % _ ±_ /j W ! ±~ — j _ K ' ~ /' j ± X? ~ ±W j ± /~ X? W X; ] ^ _ ° ±jK~ J ? X\j /' j X± = ' ~ [ j ±= h 4 > K )_/j±_ W j ; j ~ % — j ? / ~ ! /'j = ' ~ [ j ±= X= J ~ ; j ±? j W > ° /'j - ~)Xj±j ±_ W X^ = T Y * m !~ ± /' j ! ± _ J — j ? /= / ' _ / W j; j ~ % K — =' ~ [ j ±= _ ? W >° /' j ? ^ K j _ ± X? /j ± _ K / X~ ? j ? J /' 8 *~X' !~ ± /' j ! ± _ J — j ? /= /' _ / W j ; j ~ % ' _ W ±~ ? XK =' ~ [ j ±= h v ! /' j ±j X= = XJ E? X!XK_? / ~ ; j ± _ % >j /[ jj? /' j =' ~ [ j ±= X? X/ X_ /j W >° /' j ; _ ± X~ ^ = 7j / ! ±_J — j ? /= * /' j ? j; j? /' j _ ? j = / W j /j K /~ ± J ±_ ? ^ _ ± X /° [ ~ ^ W ? ~ / — _ 9 j X/ % ~ == X> j /~ Q[j? /_ ? J j /' j W X!!j ±j? / =' ~ [ j ± %±~!Xj=h

4 ' j % ±~ > j — ~?j !_Kj= — _° >j X ^ = /±_ /j W [ X/' B XJ h . h [ ' XK ' ='~[ = _ ? j ; j? / W X=% _° ~ ! /' j Z L x g x ) K _ ~ ± X— j /j ± D ♦ ’h x > j _— ~ ! % X~ ? = [ _ =

=j? / ~ ? /~ _ /' X? /_ ±J j / % _ K j W m X — ^ % = /±j _ — ~ ! /' j K _ ~ ± X— j /j ± h 8 X/j ±_ K ^ _J % X~ ? = [ j±j =j jK /j W _ ? W /' j ±j _ K / X~ ? % ±~ W ^ K /= [ j ±j ±jK~ ±W jW X? /' j K _ ~ ± X— j /j ± h Z L x g x ) [ _= _ Q ?jEJ±_X?jW K _ ~ ± X E— j /j ±h /> K j !!jK /X;j ±_ W X^ = ~ ! j _ K ' ±j _ W ~ ^ / Kj [ _= s hm &hX**U / e h ! ; - Ih 0 j _ W ~ ^ / Kj= ~ ! ' _ W ±~ ? K _ ~ ± X E— j /j ±= ^ = j W X? — ~ = / j ] % j ± X— j ? /= _ ±j /°% XK_ ° hlL>Ua / X— j = _ ±J j ±h 4 ' j !XJ ^ ±j =' ~ [ = =j; j ±_ X? W X; XW ^ _ ±j _ K / X~ ? % ±~ W ^ K /= /' _ / K _? >j K j_±° W X= / X? J ^ X= ' j W h q ~ [ j; j ±* /' j ±j /= _ =~ K ~ ? = XW j ±_ > j ~ ; j ± _ % > j /[ j j ? /'j =' ~ [ j ±= X? X/X_ /jW >° /' j =j % _ ±/XK j = h - _ 9 X? J /' j J ±_ ? ^ _ ± X /° =— _j ± [ ~ ^ W ? ~ / ' j % /~ ±j =~ ;j /' j j? j±J ° W j % ~ = X/ % _ / /j ±? h

g4X~

=K_zK XK—l

;^ 1O P ’ 6B/Kh .h x ZLxgx) /!;K/^ /X^ % XX' ~U X'U ±j^±/X^~ % ± 7 K ^ K ^ !±~— X %X~? 7- j±;/X~K; h? _ _ ^%M/±j_— ^ !%jXh 4>j ~^ K> K ±= ~K!/^/j /'j KXXj±w 2 T X _ k j 1 X Y)U7]l/»_jXa S / ' j o T ^ _ /» X e^ u ? ) [ X ? XJ XJ ! KK") T a E ’

mub


As an :lilde., \\'C mention L'ut the s.m:c thus DC\.-c:ss.inly :appiics for th.: i:,.cnt-to-c-.cnt fii:ctu;itiotu in the fractilln of dccuomagneticllly 1111.:r.JCting p3I?ldo (mainly tt0s). These tluctuatl.llAS uc rcspollSlblc for the poor jct a!Ct;;)' resolution of ooo-compcruatm~ ca!orimctas. cspcci:ill) at lligh cna~ [Ii ii::i...-:: the response .:if su.:h ..:alonmctcrs is 11sualil ..:on..,1Jcrably !aq;cr for cm sho\l.e~ t!lan for 0011-cm on.=1.

In the ati,.c:-..:c ,,f a ..-alorimctcr. or.c '11011Jd therefore nut cx~cct t.l bc .i.ble t.:> mcasucc jct c:ncrg} rc,;olution.s better t!un .!5-Jo•;, on tb.: basa .:>f u:.scl.cr mf.:irmation .1lu-nc. ~l .u1y ai.-rlJ_.-. . .\nd iilh.-c: the: contnbuti.,ns oi ,ho~cr-llg i±lr;!Cd pa rt:.:!cs h> Ll'..c L0 Jloru:u:t:r 'IJ,m.ils hJ ~c rn be ..!U4:01mtcu proper!~ foe the Ef'.\.I w ..,,,ck.. the .;;u.tluy of the .:-.1:orimctcr uu·oc?IWtwn u in pr:1c!.-cc im,x,rt.mt.

JJ .\l.iw1c!!L" .lf.-JJ dfcLI:.·

The pr,ir,..1:u:nl.!i .,r tbb mctho.l d;um tha.L the i.ey IL> IU >Uu:~~ Ill .1 LI!IC".1:-C .:J!JJJ..:r c:.,pcn:ncnt ,,. Jctcrnun.:d liy !.'x yr.inul.uur .:if the ~tectnr . ..\ lu!fh :;r.lllul.1:1l~ ,,a,ilJ !n.lk.c 1t p...-.,;s,b:..: tu recognize and dimi.'Ut.: .ill contnbutic.:o of the dl.l!;;cd pani..:lo to tJ:.c o,crali L-:t!orimcta ,i:~nal. Th.: rcmairu!ii; c.!li.1n=t.:r ,t~nal c.:,ul.! t.h1."":1 be .itt=ibutcL! :., tbe nc:utr.11 Jct compunc::tts [l lJ.

0

113

How~·cr. the q1-'Clll.10u arucs "hcthc:r the jet fragments. by the: time thci, rcic.'1 the front fao: of the calorunctcr. arc sufficiently liCpllrat.:d from Cllcll other in .:>rJcr to in,ii\xti.ally rccognil.c tbcir ..bo-i~crs. The ~t.:ral ~clopmcnt .>fthc :ihO\~crs is gQ\·cmcd b~· Lhc :',.[owe r:idius fl'\tl for the fragments tlut d~dop c:m sfioy;crs .uid by the nudcac u:1c:r.u.:trn11 lcn;;:h I;_,.,.) for the fr.ii:;ntc~

that .k~clop :udr.>n!I.: sho11o-en. If there "' ii!,!ntfir.:ant .:>•·::rl.lp bct"ccn t!ic sho11o CN 1111~.itcd b~ the: ~irious jct fra1F-1cnt,. then ,:,.en the ineu dctcctlH grani;larit~ \\oJuli.! nol m:ii.:c It p,>,.siblc 10 discnun,µc t;lC d1!T.:rc:1i: ,ho,-cr pro!ilc.

T?!c problem oac f.lL-c. tna) be iil1 ... ma1ct! wnh h!=. ~. w ~1..:h ,ho,\, ;111 C''Cllt JtipJ;,~- .._,f the SPACAL ..:alNtll'.c!cr [11f. A !x:am ,Jf ph.lru 11o:1, .cnt unto .1 thm ur.=.:t pl.u;-::t! 1.5 :u i:p,ucun oi the c:alorim.:t.:r. Im::: .11:'.1:ig p:or.s. ~cr:: s.::.:ct.:tl .111J the r.:act1011 p~L1.!u,;ts ...cu: rc1:\lrJo:J in the: .;;11::>nm~cr. SPAC.-\L "'-:li a finc-:'l'Jincd .::il.:>rim.::cr. tl:.c: elli'\:t:,·: :adi.i, ,,( .:-.11:h rc-.1J;,ut ,ell w.1, 0.1'1i,,,. t1.fJ~,\I :. Rc;i.!.:J,.t .:clLi ..lC h.io.lr.:in ..::ik,rin:.:tcr-. used L'l must e:tpenmeut.i ar,: t:, pi..-:il1:, .:o-31J l!!r.c:s urger. Ti::: lii;:w: 'lhL1,u .c,~a: ui.!1·.-1.!=I rc:a.:tiou pr.>dw.:u ~b.it .:an be d.:a:!1 Jt.iting,.us.'u:d. Howc,·cr. then: ts also .:or~,k:ablc ,walap oct"'c::n the ,ho ... cr, initiat.:d b~ thoc pa.ru.:ks. ~l.1.Jung t!i.c ir..1nu.l.m1i, srn.illa u.oulJ 1101 h.:lp t..l ro.,h,: the: cnc:r ,n, Jcr-»11 ~ttcrn.

scale icm}

KO 11,lJ f'~. '· A SPAC-\L """11 ,!Uf"l) ul ,~.., ma,;,..,., pr...:u..u (r""1 ~ p,.,o ille~ .n ..., upo1re.:m ~l!,lCI. The auc,bcn ~k thr rurri;y 1io Ge\'., .:..,,_. .. ,a: in the inci,al:wl ~wctcr cdla [l:I.

1-19

J d*)’Y —N [^ P Wq—<—q0 x’;’626* <NN_< d—N]>Ê< * v / / ^ ! j ! a—<—q05> hu ^K' WUw OU ^„B wVm8

=X? Kj T>j Kj = ^ j X= =^ K' / X ? / j;j? j j K /±~ — _ J ? j /XK ='~];j±= ^ =^ _ ° j ? W j W ^% = ' _ ± X? J /' j X± j?j±J° _ — ~ ? J =j; j ±_ j W X / X? /' X= W j /j K /~ ± h

4 ' j * ^ j = /X~ ? [ ' j /' j ± ~ ± ? ~ / /' j 7 j / ! ±_ J — j ? /= _ ±j =^!!XK Xj?/° = j % _ ±_ /j W _ — _X? ° W j /j ±— X? j W >° /[ ~ !_K /~ ±=e

8 4 Xj W X= /_ ? K j > j /[ jj? /'j K _ ~ ± X— j /j ± A= ! ±~ ? / !_Kj _ ? W /' j > j _ — X? j [ 'j±j /' j ! ± _ J — j ? /_ E/X~ ? /_ 9 j = % _ K j * _ ? W

Ta ' 4 ' j = / ± j ? J /' ~ ! /' j — _J?j/XK !XjW /' _ / X= ^=jW /~ = j % _ ±_ /j /' j K ' _±J jW 7j / ! ± _ J — j ? /= !±~— j_K' ~ /' j ± h

v? _ W W X/ X~ ? * /' j 7j / j?j±J° _ ? W /' j /° % j ~ ! 7j / m ! ±_ J — j ? /X? J * ^ _ ± 9 * W X* ^ _ ±9 ~ ± J ^ ~ ? ' — _° %_° _ ±~ j h 6 K X? ; j = / XJ _ /j W /' X= XX=^K !~ ± /' j % ±~ % ~ =j W 4 ) Z ) x j ] % j ± X— j ? / Dmnoh ['XK' = j * ^ X% % j W [ ^ X _ u 4 — _J ? j /XK k jW* [ ' Xj /'j K _ ~ ±X— j /j ± ! ± ~ ? / !_Kj X= ~K_ /jW _ / _ W X= /_ ? K j ~ ! /W — ! ±~ — /' j >j_— X?jh

x K K~ ±W X? J /~ B XJ h nh _ % _? XK j % ±~ W ^ K j W X? /' j ! ±_ J — j ? /_ /X~ ? ~ ! _ mss kj1 * ^ _ ±9 K _ ± ± Xj = /° % XEK_° b k j1 vU'I'U+ ~ ! /' j j?j±J° X= K _ ± ± Xj W >° /' j ^

— ~ = / j? j ±J j /XK % _ ±/XK j = vh v ! /' X= % _ ±/XK j X= j j K E/± XK _ ° K ' _ ±J j W * X/ [X W j ; X_ /j !±~ — _ = /±_ XJ ' / % _ /' > ° mb K _ / > j !~ ±j ±j_ K' X? J /' j 4 w Z ) x K _ ~ ±X— j /j ± * _ = _ ±j = ^ / ~ ! /' X= — _J ? j /XK !XjWh 4 ' _ / X= n /X— j= _ = — ^ K ' _ = /' j *b2;*’2 W j ; X_ /X~ ? !±~ — /' j 7j / _ ] X= ±j = ^ / X? J !±~ — /' j X? /± X? = XK /±_ ? =; j ±=j — ~ — j ? /^ — ~ ! /' j °j/ !±_ J — j ? /

B ~ ± /' j = ~ ! /j ± 7j / ! ±_ J — j ? /= * W Xj j4jK/ ~ ! /' j — _ J ? j /XK !XjW* K ~ — % _ ±j W /~ /' _ / ~ ! /'j /? X? ? = XK ! W W X? K ±j_ =j = !^ ± /' j ± h B ~ ± j ] _— % j * _ n k j1 *1 /X< /±_ ; j X? J X? _ % _ ? j % j ±% j ? W XK ^ _ ± /~ /'j — _ J ? j /XK !Xj W [ X W j ; X_ /j >° rc K — !±~ — ^ = ~ ±XJ X? _ W X± j K / X~ ? ^ % ~ ? _ ±± X; _ _ e /' j K _ ~ ±X— j /j ± A= ! ± ~ — !_ K j h u /X— j = _ = — ^ K' _ = /' j j4jK/ ~ ! /'j X? X±XK=XjE ! h h x ? W % X~ ? = [ X/' _ — ~ — j ? /^ — d a k j 1 hd■ [ X ? ~ / ±j _ K ' /' j K _ ~ ±X— j /j ± _ / _h

x ? j] _— % j ~ ! _ ? j; j? / X? [ 'XK' /' j ) m - ? XXJ XX ];~±9 _ = _ ? /XK X% _ /j W X= =' ~ [ ? X? BXJh nh 4 X/= X= _ ? j ; j ? / [ X/' _ j_W X?J X±® — j=~? h 4'j K ' _ ±J jW ! ± _ J — j ? /= _ ±K > j ? / _[ _° > ° /' j — _J?j/XK !XjW * /~ =^ K' _ ? j] /j? / /' _ / /' j X± =' ~ [ j±= W ~ ?~/ X? /j ±!j ±j [ X/' /' j — ~ = / j? j±J j/XK' % ' ~ /~ ? ~?j=h B X/j K X±K j = X? W XK _ /j /' j K ' _ ±_ K /K ? = / hK = X iK ~ ! /'j = X/~ [ j±=

mss

<Bj

\D

Ems

=Wt

EmssEcsEvgQ c s Emss

d•+ WX±jK/X~? TK—'UAXJh b B ±_ _ — j K ^ ! K = 7 ! ~ ! q e/5l k j 1 K X ^ ± / !j / + E 7 ' u j 7W X? U X ! ^ /' j X Y ~ ? \ ± Y / K ± ~ ! /' j 4 w Z ) x j / % j ± X ] K ? X 4 ' j KX±KjU h _ W ^ Y / j /' j

8 ^ ± ^ ± K ? ^ X K _ /j ± _ XM ~ j !!K = ~ !^ ~ ! /' j / ' ~ _ j ? W j ; j ~ % j W >U /' j ! ± K K / ! 0 / / h €q% /' j _ / — > j ? ±j % ± M j _ / / ' j K? j ±__ j= ~ ! /' j X8 7K ? j — ] )!X k j 1 4 > j % ~ X? / K ~ K — % ~ X9 X = /~ T>j "±=Xe!Kd ~? ~ ! / > j ! ± ] K ± X j - h? 7 ~ ^ ^ / h X j C X z~ j K ~ ± j / X j ^ z / h

mcs


,iinct the cdl !>UC i.s mch that e,·cn d:L-irotnagDCtic ~O\loers usu:i!I} cnJcd up .shllrin~ theu- cner!D mui~ ,aer.tl i:dl.s ll1 tll11 JcLO.·t.:ir.

The quouon 111hcther or not the jet fr:1£I11.:nts .uc mtTu:icotl} o;c;xi.r,ir.:d :s llUinly Jcu:nnin.:d by l\\'O l:IL"tlln:

(l J Th.: ifut.1)!1L-c bc111,eco L'lc .:alori~cer· s fr<lut f.J.:e anJ the bcim hoe. 1\hcn: chc fragmcnt.1-u.:>n ta~ pLu:c. anJ

l~I T!ic stn:ngth of the rrugnctic fielJ that i.i LL'-CLI to ,epara!C tr..: durgcd Jct fr:igm.:ots frilr.t ca..:h other.

In o1JJiti.,n. the JC! cuer~,y :lllJ the t~ pc L•f jct ffr.1i;mcn11::1i; -iuarl.. . ..!1'iuar\ or g!u.~n, n-..iy p:.t) .1

r<llc. We imc:stl,::11c:J this iuuc rM the proi:o-cJ Tl:.SLA .:.\p..:nmc:it [DZ. 1oh:.:!i i.s .. "4:!1pi:cJ _.uh .1

-+ T nu;;nct:.: tid.i. \\ hi!.: the cai.:.ru:?>Cter fr,1nt fa.:c ,~ l•-..::it.:J .11 .1 J:.,1an.:i: 0r l.b!! m from the bc:.im line.

A,caco.li::~ w fig. 3. ,1 :~.1mcl.: prnJu.:co.l ,n the fr.1~1n.:nt.1.u,>n L,f .l 100 G.:V <i!J..l!k .::1::10 1~;,1-c.1lly 'l GcV 1 •)t 1 •. ~·f ch.: .:ncr~.:, :s car:1;:J !,) tl-.c I \I

..... c '.J ·-

.. ,, I

~[ ---. .'~' I .. :..::_,,· ,~,

i

,.,

·ll.O '----~ ....... ----'---------~--'

mo:1t enerb-etic p:1rnclcs 1. U I.bis paru.cle ii clcc· tnc.:illy .:~rgi:d. it will Jenat.:: from a str:ii;;ht path by 19 ,::n before reachiu~ the TESLA c-.1lorimct.::. :is a result of thi.; magnetic tied. Tlut is 3 ti= a.s much ;is the cJCt!r~ drnati<>n fr<>Dl the jct a.~:.s 1C\u!Un!,; from the mtrins1c tran"·a~ molt".c:uum of the Jct fragment

For the s.iftcr y.:t fr.1!,;ID.:nts. ~ etTCl:t of the m.igneuc !kid. .:.:imp:iro.i w t,ut uf the inm=c p _. mc:::-.. ,c; fwtbc:r. Fur c."Urnplc • .t J Gc\'_:c- n:

lC-J\C:!i:t~ :n J pl.i::c ;,crrenJicul:.i.r to the m.l!,'!le'.JC

t,cii.1 ·•tll de-.i.ite b~ ti5 L1'n from 1u or.~inal d:rca:111,,n upun .1.m\.Jl .1: the .:a!..mtr.ctcr·,; !r.:,nt fa.:c. -I time. a.s mu.::i as the ctTa:t of the intn.i!sic r .. A:11 r,j .. ,m \\1th .1 m,1Cl' ... -ntarn <~ GeV .,. v.1ll not rc:-.1.:h the c:1lllrimctcr at .11!.

.-\;1 C:\.unr-J.: .:if .1Il :l'~-r.c m -.,.h:~h ch.: :LI'\! n11i;!11 "orl.. .1,- .1nt11.::p-.1:cu :, ,buw:1 in Fi;;. ii. Tll:., 1, Jn .:·. ::11 ,.-1111 .l k:a.!in~ rot' m.:,on. The i:h:.r!e".:tl fr.1~mc1ll> .Hi: hcnt .11,a~ by the m.s;;n.:11.: fielJ. c.,

-.·.;..:h an e,1::.11 th.it !h,;:ir ... 'tu....,cn J., r.ut ull.:rfi:rc I\ 1th !h.: I mo,1 ener-det1::) ph..l!ull .in.:,. r:!c crrdcs 1:1.!:.:.1!c 1:1.: c:wractcr.,c • .: sue ,1f the .-.ll,1.-.:~,

10

Q f S.6<;,v,

·1<> ._/

.,.5 -.::0 ------------------.,co -50 0 50 1()0 -.::0 -10 0 10

cj, direction (cm) Fis. ~ Fr~i.,c.:.,a .,f _. :oo ~\' "u.ui: IC'l a:Jb .a lead!~ !t" in Jh< "-'ll,•·:,:-.,:,cr .:,f me TESL\ e1.crnun1. Th• cn:b!s . ...t.:.,.re 1h.: .:b=rrnu,, l>ler.ll ~n,; .,, t~ ur.,Gcn .:c-•l.:p:'1 b, ~ f~--=1m. J.llo! lb< 11w:iben repre.:1111~.c .....-~ oJf th< rr"F="'in Ge\' n.. Fvtlll 1llJl1 ~o>Cffff'Jn.il i.. ,be .f;r.,,:i:.,n ,,I ,be (r~1,n~ .;...n. ,lo: Jc'-1 i.,c =~ .kw.JL

150

c pN<9>S 'N $ ] N W'5E—q0 [NRR_S —NNq _ * E 1 ± X x X ' X ± sm k v R :— $ x ± 7 5R0—, Ev *OXW X jN<%j3 .Vj*.j[N m X

X? X /X_ /j W >° /' j 7j / ! ± _ J — j ? /I * Xhj h % - !~ ± K — =' ~ [ j±= * !~ ± ' _ W ±~ ? XK ~ ? j = h 6 j ' _; j _ ==^ — j W _ K _ ~ ± X— j /j ± [ X/' /' j ' XJ ' j = / % ~ = = X> j Wj?=X/° * Xhjh [ X/' /' j =— _ j = / % ~ ==X> j ; _ ^ j= ~ ! _? W ih—* m

_ ? W ms K— * ±j=%jK /X;j ° h 4 ' j =' ~ [ j ±= !±~— ' _ E W ±~ ? XK ! ± _ J — j ? /= _ ±j X? W Xj ? /j W >° ~ % j ? K ^ j j= h /> j j j K /±~ — _ J ? j /XK ~ ? j= _ ±j ±j % ±j = j ? /j W >° /' j =' _W j W K X±K j = h 4 ' j j? j±J Xj = ~ ! /' j !±_J — j? /= T X? k K 1 X _ ± j X? W XK _ /jW X? /' j ! XJ ^ ±j h Q ? ° % _ ? XK j = K _ ± ±° X? J — ~ ±j X' _ _ v k j1 _ ±j =' ~ [ ? X? /' X= W^%) _;h [ ' XK ' K ~ ? Kj ±? = _ 7j / _ / H f s v% K ±% K? W XE K ^ _ ± /~ /' j > j _ — X?j'h 3 ^ _ ±9 = /±_ ; j X? J X? ~ /' j ± W X±j K /X~ ? = [X W j; j ~ % °j/= /' _ / _ ± j =~ — j[ ' _ / > ±~ _ W j ± X? /> K AB W X±j K /X~ ? h B XJ 5> ='~[ = _ K ~ =j E ^ % ~ ! /' j K j ? / ±_ u s h» us K — £ _ ± j _ =^ ±±~ ^ ? W X? J /' j TQh8' % ~ X? / * [ ' XK ' ±j % ±j =j? /= /' j ’K / _]X=h

q ~ [ j; j ±* /' j % ±~ > j — = [ X/' /' X= — j /'~W ^ ? = K !~ ± 7j /= [ X/' j? j±J j /XK bx[;H2D °j/ !±_J — j? /= h g ~ — % _ ±j W /~ = ~ ! / K' _ ±J jW !± _ J — j ? /= * /'j j !!jK / ~ ! /' j — _ J ? j /XK !XjW ~ ? /' j =j % _ ? XK j = X= =— _ _ ? W h /' j ±j !~ ±j * /'j° j ? /j ± /' j K _ ~ ±X— j /j ± X? /' j =_— j ±j J X~ ? [ ' j ±j _ =~ /' j /hE= ! ± ~ — 7 ]“; W j % ~ = X/ — ~=/ ~ ! /' j X± j? j±J ° 4 'j — ~ = / j? j ±J j /XK % _ ? XK j X? ~ ^ ± mss k j 1 * ^ _ ±9 7j / K _ ± ± Xj = * ~ ? _; j±_J j h E b k j1 h v ! X/ X= K' _ ±J jW * X/ ±j _ K' j = /' j K_ ~ ±X— j E/j ± A= ! ± ~ ? / !_Kj _ / _ W X= /_ ? K j ~ ! r K— !±~— X/= = /±_ XJ ' /E X? j Ej ] /±_ % ~ _ /j W ~ ± XJ X? _ — ~ — j ? /^ — ;jKE/~ ± h 4 ' j W X= /_ ? K j > j /[ jj? /' j X— % _ K / % ~ X? / _? W /> K °j/ _ ] X= _ h ~ ? _; j ±_J j h p K— h

BXJ h b = ' ~ [ = u j ] _— % j= ~ ! j ; j ? /= [ 'XK' % ~ =j ; j ? ~ ^ = % ±~ > j — = !~ ± /' j w B - h v? _ K_=j=* ~ ? j ~ ± j ; K ±_ j ? j ±J j / XK K — =' ~ [ j±= !_ [ X/' X? /'j ±jJ X~? K ~ ; j±jW >° =' ~ [ j ±= J j ? j ±_ /j W >° jjK/±XK_° K ' _ ±J jW 7 j / ! ±_ J — j ? /= h Q ? j — XJ ' / _ ±J ^ j /' _ / /' j ~ ? J X/^ W X? _ = ' ~ [ j ± W j ; j ~ % — j ? / ~ ! /'j=j /[ ~ /° % j= ~ ! °j/ ! ± _ J — j ? /= X= ;j±° W X! !j ±j ? / _ ? W /' _ / ~ ? j K ~ ^ W ^ =j /' X= X? !~ ±— _ /X~ ? /~ W X=j? /_? J j /' j j?j±J° W j % ~ = X / % ±~ !Xj=h q ~ [ j ; j ±* X/ X= X— % ~ ± /_ ? / /~ 9 jj% X? — X? W /' _ / ' _ W ±~ ? =' ~ [ j ±= /°%XK_° W j % ~ = X/ ~ ? j /' X ± W /~ ~ ? j ' _ ! ~ ! /' j X± j?j±J° X? /' j !X±=/ ? ^ K j _ ± X? /j ±_ K /X~ ? j ? J /' * [ ' XK ' K ~ ? = /X /^ /j = ^ =^ _ ° /' j j j K /±~ — _ J ? j /= e K _ ~ ± X— j /j ± ;jK?~? ~ ! /' j W j /j K /~ ± h v/ /=h /' j ±j !~ ±j * ;j±° X9j ° /' _ / X/ /= X— % ~ ==X> j /~ W X= j ? /_ ? J j /' j W j /j K /~ ± ' X/ % _ //j ±? = !~ ± j ; j? /= ~ ! /' X= /° % j X? /~ K ~ ? /± X> ^ / X~ ? = !±~ — /' j K' _ ±J jW 7 j / ! ± _ J — j ? /= _ ? W ! ±~ — /' j ~ /' j ± K ~ — % ~ E? j? /=h v / = ' ~ ^ W > j j — % ' _=X\jW /' _ / /' j W j% XK /jW j ; j? /= [ j ±j ? ~ / =%jKX_° =j jK /jW /~ X^ = /±_ /j /' X=

% ~ X? /h ps® hh ~ ! _ ' XJ ' Ej ? j ±J ° 7j / j; j ? /= ±j =j— >j /' ~ R =' ~ [ ? X? B XJ h b h [ ' XK' [ j±j /_ 9 j ? !±~ — /' j =_— % j ~ ! /' j !X±=/ m s j ; j? /= J j ? j ±_ /jW X? ~ ^ ± - ~ ? /j g _ ± ~ = X— ^ _ /X~ ? = h

RWg \6!„;^*Yb2 „3 x2 U’V„;’Y2^2; H’YV’G

B ~ ± /K _ =~ ? = W j =K ± X> j W X? /' j % ±j ; X~ ^ = =^ > =jK E/X~ ? h /' j K _ ~ ± X— j /j ± =° = /j— ? jjW = ~ /' j ± * ^ _ X/Xj = >j=XWj= _ ' XJ ' J ± _ ? ^ _ ± X /° h v? % _ ± /XK ^ _ ± * X/ ? jjW = _ J ~ ~ W ' _ W ±~ ? j ? j ±J ° ±j = ~ ^ /X~ ? — ~ ±W j ± /~ — j _=^ ±j 7 j / j?j±J Xj= [ X/' J ~ ~ W % ±jK X= X~ ? h 4 ' X= ±j = ~ ^ /X~ ? [X W j /j ±— X? j '~[ [ j ~ ? j K _? W j /j ±— X? j /'j K ~ ? /± X> ^ /X~ ? ~ ! /' j % ±jK X=j ° — j _=^ ±jW K ' _ ±J j W 7j / !±_J — j ? /= /~ /' j V„^„V K _ ~ ±X— j /j ± = XJ ? _ _ ? W h /' j ±j !~ ±j * /Xj % ±j K X= X~ ? ~ ! /' j ? j ^ /±_ j? j±J ° ~ > /_ X? j W _ ! /j ± = ^ > /± _ j /— J /' X= K ~ ? /± X> ^ /X~ ? h

tBs ( ,£*N— OR0<£ ,NSN<q<d,Nv? ~ ±W j ± ~ * ^ _ ? / X!° /' j _> ~ ; j = /_ /j— j ? /= * [j

' _ ; j = /^ W XjW /' j — j ±X/= ~ ! /' j w B - !~ ± _ j _ ~ ? — j /j ± = ° = /j — [ X/' _ ' _ W ±~ ? XK j?j±J° ±j =~ ^ E/X~ ? Y k sW ps® G ~ # c A h _ ? W _ ? — x ; _ ^ j ~ ! mhch 4 'j=j % _ ± _ — j /j ± = _ ± K /°% XK_ !~ ± /> j K _ ~ ± XE— j /j ±= /' _ / [ j ±j ^ = j W X? /' j ) w L j ] % j ± X— j ? /= h 4 ' j 7j / ±j =~ ^ ^ ~ ? / ' _ / K ~ ^ W > j j] % jK /jW ~ ? /' j > _ =X= ~ ! /' j w ?j±J° - ~[ - j /' ~ W _ % % Xj W /~ =^ K' _ K _ ~ ±X— j /j ± = ° = /j — [ _= j ; _ ^ _ /j W X? /' j !~ ~[ ^ XJ [ _; h

6 j W X= /X? J ^ X= ' /' ±j j /° % j= ~ ! 7j / !±_J — j ? /=

!_ ' L _ ±/XK j = / ' _ / W j ; j ~ % K — =' ~ [ j±= X? /'j K _ ~ ±X— j /j ± T— _ X? ° °= !±~ — \ “ W j K _ ° a

T> ' Z ~ !/ ' _ W ± ~ ? = /' _ / W ~ ? ~ / X? /j ±!j ±j [ X/' /' j K _ ~ ? — K /± XK 7 j / — j _ =^ ±j — j ? /= _ = _ ±j =^ / ~ ! /' j — _ J ? j /XK !Xj W h 4 ' X= !XjW ~ / ' j ± % ±j ; j ? /= /' j — !±~ — ±j _ K ' X? J /' j j _ ~ ? — j /j ± _ / _ ~ ± > j?W= /' j — / ~ = ^ K ' _ ? j ] /j ? / /' _ / /' j° j ? W ^% ~ ^ /= XW j /' j ° j /EW j !X? X? J K~?jh

TK ' q _ W ±~ ? = / ' _ / W ~ K ~ ? /± X> ^ /j /~ /' j K~ ~ ±XE— j /±XK 7 j / = XJ ? _ = h

v ! /' j 7j / K ~ ? = X= /j W ~ ? ° ~ ! % _ ±/XK j = ~ ! /° % j = T_' _ ? W T>'h /' j? /' j w B - [ ~ ^ W >j _ % j ±!jK / /~ ~ /~ W j /j ±— X? j X/= j ? j ± J ° h v / [ ~ ^ W >j ? ~ % ±~ > j — _ / _ /~ Jj / = ^ > E m j ? j ±J ° ±j =~ ^ /X~ ? = !~ ± [2^( [ X/' j? j±J Xj = X? j ] Kj == ~ ! m s ' k j1 h q ~ [ j; j ±* /' j K ~ ? /± X> ^ /X~ ? = ~ ! /' j = j % _ ±/XK j = /~ _ ±j_ X= /XK 7j / ±j = ~ ^ /X~ ? — _° h ! ~ ± _ % ±_ K /XK _ % ^ ±% ~ = j = * >j

mcm


initi:J.tc<l by the jct fr111,;!llalts.. i.e. l':,a for cm ihov,crs., Au.I for tuJroruc ooc:s. We 1u,·c: a,m1a:c<l .1 o.::ilonmctc:r '°' 1th the highest possible: &n.-.it y. u:. \loltb the .malL:st p,issiblc: ~-:ULICS <lf µ.., :m.! .i..n1, I .1.cJ JO .:lII, rc:spo;ti,d}. The --hov.c:rs from b.lJr,,nic fr.:1;;mc:nu :ire inJicito.f by open cll'C!.:~. the dc.."trom:1g:ic:1c .>no Jrc rcpr=i..:d by the: ih.iJoi .:!ttl= The cnc:rllic,. llf !!le fr:ii;m.,--:-.1" 1 in C..:Vt .1rc indii.:atcd 1n the figure. Only p-.utidi!> &.::1CT)1ng m,m: thJJl I Ge\" uc: sho-..n L'l this J1.pu:,. '°'h:4:h ~Ol!s\:rn.~ .l jct Jt I/= 0 li:-,:rpcr.<li.:uJ.11' :o tl:c bc:-.1m lincl. Qu.1r~1 tr.oc:llini; Ill other Jir~1.ii.>r.s "'ill J,:,dop ,=t. tiut arc ;omC\,h.ll brOJr.lc:: in the 'I Jirt\:tion. Fii; Sb shO'#S a d,,scup of the ,cntnl ..i(} .• 40 ,m! :ire-.. ,urro.inJi.ci; the (0.U) pomt. "'h:ch rer,r:\e:u.s th,: i-:t .:iu,.

H.>-..e~e:. t.ic ?rllhlcm, ~ith this mcL1,,J .m;c for jcu 111th c:~~u.: di.trr;r:J ,ct fr;i;rr.icnts. C,1m;,an:J t,l wft .:h.ar;;cJ fr.1gmcnu.. the elf~! 0r the m.1~'llctic ticlJ on t.'t.:sc ~;imdo Li .mall .tr.J. tit.:rcfotc. t!t.:~ cntc: the .:al,m=t.:r 1.1 the ,.u:1e region \~l:c-re .ih,1 the 1 :"~ fr.:imi ~0, dcp.->..1!

most nf th.."'lr energy_ T:1.: mo,;t cna~-c:u: p.;inid,: i;1

llur 100 G.:\" qilrk jc:: carr.cs. .,n .ncr.igc. ~9 Ge\'. If It is 1.--h.ir1:,'nl. it rc:u:h.c:s the .:.tl.-inmc-1s::·i irllnt f..i..:c at a duun...: .:if 6 ,:m from 113 'i-tr.light-lUlC~tr:lpoiar .. --d ori!1m.il momentum \C::·

tor. The: .±bu~-.: i>..-t1,,.-cn the im~....:: pvin! au.! the JCt :i.u.s is. t.Jll .I\ CI:l!:,'C. 7 .. -m.

Fii;. 9 d~o~-1 4 cump:..~ of c:1·c:nt.s \lobich pose 'iCllous i::r.-,bkm.s for the: EF~I. 14 all c:i,ics, one .:ir ,e\c:r;i.l cneq;ctic: cm mo ... l;n fall .... ithin the rci;j~,n co,crcd by iho,...crs gcna-.l.!CJ by clo."lnl::ill) ch~ jct fra;;men!s. One mii;ht argue that the longnudin.ll J-..o\,cf de,clopmcnt of th= ~ll !~po of jct fn~mcnu is ,·cry JiITcrcnt and th.u one .:ould use: th.is 1nfornuuon to dllcnt:uig.le the energy depow (!rotilc:s. H.:,11.cvcr. it i.i llDporunt to "ccp in minJ Ltw.l haJron \bowen l)pi\.-all) d.c:pos,t one tlurd to one half of their cr.erID- ID the lint nuclca.r intcr.iction k:igth, 11, bich «:oniUlutcs 11Sually tbe dcctromagnet:a: .::dorunc:tcr ilXtioo iJf the dcto:tllf. It as. thc:rcfon:. ~cry lw:f~· tlwt 11 is impos.ubk to discnungk the dctect.:ir hit p-.ittems for C\ents of thi!i t}-pt int.:> oontribuuon.s from the i:bat£cd jc1 fr..s;P!!CDU anJ from the other ,:omp.>

acnu. It should be anphasued tlut the Jcpic-..cJ e•·cnts ,,ere n.:it ipa:i:iilJ .clccteJ to illustr:ue this

151

l !$

point. 70° .. ..:,f :sn hi~ncrllY jct ~-cnl3 resemble tha1<,c illiJWll m hg. 9. whDCh were ulu:n from the ;ample of the lir-t IO C\COIS !:,"CllCl'"Jtai Ill our .'.\lame C.ulo sunulauons .

For tc:bc:tns dr.:;.cribcd 111 t.'ic ptc\iou,1 ~u~uon. the c.ik,rin:.c:cr i~~t.:m nccilii ocl:cr qu:iliuc:-. ~es a high granuuri!)I. ln p:artii:ufar. it BCl:l.!s :1

g~•i:J llaJ.r.:.n .:acrir- ::::iolut:on !!l or.!.:: to measure .JCl cncri:10 "'it!1 ;;ood pn:\:Wllll. Ti1e1 rc:,10fution 1\ ill Jci.:r::unc hu1\ '14.CI! »11,: can J.:1.:r.:ii."!c th,:

.:ontnbution of t!l.:: prc-.:1.sd~ m=,ur::J .:!ur-gcJ jct fr.i,.m~nts m tl'.c :<JtJl ~-a:onmetc-:- ;i:::ul aaJ. thc:°rcfor.::. the r,ro:rsr,,n ,lf :he ncut~I ,::1.:r!,'.:,· .:ibt.111:L"l! ..1ft.:r !\uhtra.:t:u~ this .:,H11r:bat:-1n.

J . .J I .\funu Curl" ,maJ,mum l:l <>rJu- tiJ ~\Wntlf:, th.: .IOO~C sr.atellll!JIL>. 11.C

h.1\e studio.! the rn.:rns oi the: EF'.'1,I fr,r a .:akinm.ctcr ,~ st= ·~th .i !l.w:ilr.ii: cm:rgy rc<;.;,[urwn t1 ·E = 70"- -i \-' £ - 5', ;ind Jll ,.,-,, value of 1.5. The~ par.1m.:1er, :1re t;;,ic:il ior the .::alurinxtcr-. :hat 1,.:re u.,c:tl m the LEP ::.'lpc::ur.=nts. The JC! rc,,oluuoo ~t i:ou.!J be ap::1.11:J L>ll tc.: ba..,.s of the: Enerl:l:> J-10,, ~lcthoJ appl..:J 10 su.:h :i .:::i.lc:trnnetcr ,:,~tern was c• ah.::ito.! in !.l!c follu1, u1g W.1).

We J1su.'1gul!>h three t}pcs of JCt fra,;mcnts·

fat Pamclcs th.it dc~cl.:ip cm !i..ti.o .... er.. in the .:a!or;r-.:".cr ( t:ui."11:; "f!; from z!> JC\.~ H

tbt &>ft b.ldron;. tlut do not intafcrc with the calorimetric jct mcu1.1rcmcnts u a result of the lll.l~ fu:!J_ This fielJ either plC:\COU

them from rc:iching tr.c c:il,mrnc:c:r .11 :111 ~,r bcnJs thcm to ,;u,d1 an ctcnl ll!.it they c:ld up ow.sid.: the }Ct-Jc:lini.ng ron.:.

{.: I H.1Jrons :.hat Jo con!tibutc to th.: calorimetric jct signals.

If the jct i:on.st!iti:J onl)· of particlei <lf t}pes (a) and (bl. then the EF.'.\f .,..ouW be a perfect tool to determine il\ energy. ft would be ni> problem Jt all to ~'Ct rub-I~;. enc~ rooluuons for jc:ts with

encqtia ia ocos of 100 GcV. l:fo'-''C"cr. the contnbutiL>ru t.Jf thc:sc part1cli:s to a realinic )Ct

rc:s.olution inay. for .ill praL"Ui::il purpo,ic:,i. be

c pNN,>0* —N $ < N W S W 0q 0 p RN0RS 5S £q*% , —NvS 9 X? k > q N— $ :dRq05> } .jfj3 [V" *[x N{

=tD ^;

'BE

Ems!v

v h+ IEEEEEE% % # E ©X

E- . /

Ean 'X W —X n£ n=< /~ ~ /; oeXdl WXXX]/X^^ K— '

4 Xo =h B ~^ ± j ^ X ? % > / ~D e~ln k K 1 g ) X±±9 K / X _ A/ X K = ? ± ^ K / ^ ± _ ± W ±±jJ X?K?XX* K ^ /€ R 1 < S N>— =W ^ ±XK _ X/K ± ~ X>j 4 !Z)x ±]%— — K?) 4'j KXKWK= h X; hW j /'j ['j±x/Xj±=^K 8 Xj±=X jX±=j?^~_= ~T /'j 8[±_j±. jj;K/^%jW >° /'j T— j/±j?/Xh ♦ /'j ^? j> j? hA±%— jj/X /'j j?j±JXj= si /'j /±~7K— j?^h sm 8K1 4'j % ~ ^ ^ hQ ? v K^j?/X%~KXX= /~ /'j j/±jX/^~_ ~4 /'j /X/XKKj?K/_= *^_±!Kh Q _% X' ~ ^ K ? X?^/_jjXX >°

% ? ± /K ~ K_±±°X?J X / >^ =/ m gXj1 R R < zj;W~!;?J — /'j j/%~_ } M . d{ K— U ^/±±~^X^'?J /'j j / ]]hX X ± j Wj%^/jW h Zjj — / !~ ± —~±j XZj^XX

K~ ? = XW j ±j W ? j J XJ X> j h 4 ' X= ±j = ~ ^ / X~ ? [ X/ >j K ~ — % j /j ° W j /j ±— X? j W >° )>j % _ ± / XK j = ~ ! /° % j ’j ' _ ? W h — ~ ±j X? % _ ± / XK ^ _ ± * >° /' j ! ^ K /^ _ / X~ ? = X? /> j = /K /^ = /' j° J j ? j ± _ /j X? //j K _ ~ ± X— j /j ± h 4 ' j ±j !~ ±j * X? ~ ^ ± C ~ ? / K g _ ± ~ = X— ^ _ /X~ ? = h [ K W j /j ±— X? j W /' j N X E - £ = XJ ? _ !~ ± _ JX;j? [2^ > ° = — j _ ± X? J /' j j? j±J Xj = ! ± ~ — /' j !±_ J — j ? /= ~ ! /° % j TK' [ X/' /' j ' _ W ±~ ? XK K _ ~ ± X— j /j ± ±j = ~ ^ /X~ ? _ ? W _ W W X? J /~ /' j =j /' j j ] _ K / j ? j ±J Xj = ~ ! /' j % _ ± / XK j = ~ ! /° % j !_ ' _ ? W > 'h

j / ! ± _ J — j ? /= [ j ±j =jjK /jW _ = > j !~ ±j _ KK ~ ±W X? J /~ _ ! ± _ J — j ? /_ / X~ ? !^ ? K /X~ ? ~ ! /° % j Tm'E 4 ' j W X= / X? K /X~ ? > j /[ j j ? ' _ W ±~ ? = ~ ! /° % j = T>° _ ? W TK' [ _ = — _ W j ~ ? /' j > _ =/= ~ ! /' j — ~ — j ? /^ — ~ ! /' j

% _ ± / XK j = h 8 =^ _ ° * [K K ~ ? = XW j ± j W ' _ W ±~ ? = [ X/' — ~ — j ? /_ d m k K 1 ij % _ ± / XK j = ~ ! /° % j T> Xh _ ? W /' j ±j = / % _ ± / XK j = ~ ! /° % j !K 'h > ^ / [ j _ =~ ; _ ±Xj W /' X= /' ± j = ' ~ W /~ = /^ W ° X/= j ! ! j K / h B ~ ± j _K ' ' _ W ± ~ ? ~ ! /° % j TK 7 h [ K W ±j[ _ ± _ ? W ~ — j ? / ±° " Y ! ± ~ — _ k _ ^ = = X_ ? W X= /± X> ^ /X~ ? [ X/' _ K j ? / ± _ ;_^j J X; j ? >° /' j ! ± _ J — j ? / A= j?j±J° T " / l _ ? W _ [ XW /' J X; j ? >° /' j ±j = ~ ^ / X~ ? !^ ? K /X~ ? * j hJ h h * f ahp k j1 ! ~ ± _ ms k j 1 ' _ W ±~ ? XK !±_ J — j ? /h 4 ' j ? * /' j K ~ ? /± X> ^ / X~ ?

~ ! /' X= ! ±_ J — j ? / /~ /' j K _ ~ ± X— j /j ± = XJ ? _ [ _= W j /j ±— X? j W /_ 9 X? J X? /~ _ K K ~ ^ ? / /' j j !!jK/ ~ ± /' j N$Z> ; _ ^ j h 4 ' j K— =' ~ [ j ± ! ± _ K / X~ ? [ _= /_ 9 j ? /~ >j : —Sm m E " ± ^ m m _ ? W /' j = XJ ? _ [ _ = K _ K ^ _ /j W _ = O h f kLc3„Y # T v E i * ' U i j 7 "mzE 4 ' j /~ /_ N w B - N

mca


!II ...... --------....... --..., ;a) bl

10

IU-1 :r-1 ,,

._,, ii -~ f -~ ____________ __.

g ;u r---------~---, ,_ I f -,: ! al: CJ ! :: r·rn r ._Vil I

I~ r >-:----/ /J ,'1:' .._, ,,,.---; t , \ ~- ' ,. ....

l / -.,1\'\ .. , \ '

I) i~ -~ l i i • I~ ..,.\ ' i ' ,/ 'J ,, \ / ~. ' ' /

f \.;: ', / '-, / l r----- ...... ~-·l"."1 ~ 'Ji" •t: .,,.- - ,,:~·1

i

:,, ~-----~--~--~ .Y) .111 . l(j Q ;:1

I) di1~"\:!JUII IC:IU)

1·,! ~- fuur c,u::i;,a .if !O'J Gd' <;...uk . .co oaatb ~cl.I:-~ !r~;;:11,:au. O:.:L-cte! .ii 1b.: .:i:l.,r:=1.....- .,, Ille T[:.L\ ~~..:::!CIL

Thoo cm:i:s ;6.!:,:;ue 1k .:h.:r.,.;1..-..u.: llicnl 1!1.-::'2111.:.IIS ~, lb: ""'"'"" .:... ....... ...,rec b, '"" tr.i~i:-... Ml. J..:a: ,:.. n.w:,b,n "'F""""' ,he clU:t;l<S .>I tho: ir.y::ncau. .n (.;c\' The l"JIILI il>.JJI """1!:1f'ICI!> :.> the .:a=u.,11 .:,l lb: ir.lp:CJellp qiwrk. Unit dw .. cn •=&! ~,parta:l&:1 arryu,~ .a1 li:i&s1 : u,,\" ;ind ~Dr en 1he n,gi.MI '4 .i:i , .SO an" =r~np Iii., _w:1 .ua ,.,., d"l'a..ted. Sn, int fur ai.ire 6ct.:lll ..

collli,i..,.cJ nci;lii;iblc:. Tim roolution ,..-ill be complctcly Jctamincd by the particles of t)pe le) a.Dd.. rr.ore in parti.:ubr. by the: flucuutio0.> in the ,1gD.lls they gcncr:ite in the c:il.'.lri~r. Therefore. in our '.\!ante C.ulo sunuLJ.tions. we deu:nnin.:d the "EF'.\l"" signal for :i i;i~c:n jct by .;:mc:iring the: enc:rgiel rrom th.: fr:igmcnt~ or type (c) \\ith the !tadtoruc '--a!onmc:ic: rcso!utiun :1nJ adJ~ to these tl-.c CL1..:t .:ni:rgic:1 oi the particles of t~·pc (3)

anJ (b). Jct fragmcnu 111-cre sd..--ctcl ..tS before ~ruing

to 3 f:agmcnutiun func1io11 of type (I). The .futilh."tion bctwcxo hadrons of t)-pc:$ (b, and (4!)

\\a.-. made on the basis of tbc momentum or the

152

parucn Us=lly. 11,,: consiJctcJ haJrons 11,ith momcnu < I GcV/c particles or type t_bl. and the rest p;trticlcs of t~-pe IC). but 11,,,: also \·:tJie.J this tbrc-.;Ji.1ld 10 stud)' iu dfo:t. For c:ach !J3..!ron llf type (CJ. uc: drew a r.1ndom entr)' 1£...l from a GaU!isuo dism bution with .1.:cnr:11 ~a!uc gm:11 b~ the fr.1grncnt's energy t £,J and a \\kith gh-c:n by th.: rc:soluc.on fonctioc. e.g.. a = :!.. 7 GcV for a 10 GcV hadronic fragment. TI>cn. the coctnbuuon of this fragment to the calorimeter signal 111·:is

detcnnincJ t.1k.mg into .1...:i:ount th.: e!Tc:L"t of the ~/h \alu.c. The =m sh.:iwcr fraction was t;i.l;..-n w hc f,,. = I - £:;a.ta and the Sle"n:11 was ~~"111.itc:i.J a5

S0 = EA/- -(1-J;,_)h,~I ii]. T".ie total ··EF!l.r·

c p Nu >q 5N R < [ QR N<S 0 [S C* ^ , q %qE 7 X L x ^ !j = WdRq0—> } 'X/ X /PL / .R S *ZV K v v .

mcss

’ X±i*~ E n o

NC X— ±E

m I

»l eO ?~ ~ e~~ h—~ /Uo~j/ ■U+ d »/ z U

2T-T -”■ ( pp* c p” ) pY ] K T £ £ £ c c )£] - ■ _ _ £ *;s ; c Bc y » p j)o' 6 pys p"yp / pp C* H i i>T y y ■y y p^ ] C ^)/ ■ _ " • >£ c ■Y _: *T ■ -, y > p ^ y ] * 2*iTT n k ■, ^ J C 0 j — X/U Y » X _ e ^ ) ^ X ^ / X j ; ± h9 j Az /? / X ± X ~ z — /' j X K / X

= XJ ? _ [ _ = !~ ^ ? W >l =^ — — X? J ~ ; j ± _II !±_ J — j ? /= * = !~~[ Xh

w ?j±J° Tk j1 '

E °U ! * U Z x h; vE'

w ] _ — % j = ~ ! /' j ±j = ^ /X? J = XJ ? _ W X = / ± X> ^ / X~ ? = _ ±j = ' ~ [ ? X? B XJ h v/'h B ~ ± ± f r ’K /= h /' j ± j = ~ ^ / X~ ? [ _ = ! ~ ^ ? W / ~ >j 1 hnR _ / m8s k j1 _ ? W r hr U~ _ / ZgQ k j 1 h g ~ — % _ ±j W /~ /' j ±j = ~ ^ /X~ ? /' _ / — _° > j j ] % j K /j W !±~— /' j K _ ~ ± X— j /j ± = ° = /j — _ ~ ? j * /' X= ±j % ±j = j ? /= _ ±j _ /X; j X— % ±~ ; j — j ? / ~ ! a n N hX _ ? W mbU~h ±j =% jK /X; j ° h

6 K ' _ ; j = /^ W Xj W /' j j !!j K /= ~ ! /' j w B - ~ ; j ± _ [ XW j ± _ ? j j ~ ! j? j ±J Xj = h 6 j _ =~ ; _ ± Xj W /' j % _ ±_ — j /j ± / ' _ / Wj!X?j= /' j 7 j / /° % j Z F l _ = [ j _ = /' j — ~ — j ? /^ — /' ±j = ' ~ W !~ ± /> K W X= / X? K / X~ ? > j /[ jj ? ' _ W ±~ ? = ~ ! /° % j = T> ' _ ? W vK' TillU'h 4 /j ±j =^ /= _ ± j =^ — — _ ±X=jW X? B XJ = h mm _ ? W mah

B XJ h mm =' ~ [ = /' j K _ ~ ± X— j /± XK 7 j / ±j = ~ ^ / X~ ? ~ ! /' j J j ? j ± XK ) w L W j /j K /~ ± T /' j W _ = ' j W X? j '* _ = [ j _ = /' j 7 j / ±j = ~ ^ /X~ ? ~ ? j — XJ ' / j ] % j K / [ ' j ? _ % % ° X? J /' j w B - /~ 7j /= — j _ =^ ±j W [ X/' /' X= W j /j K /~ ± * _ ==^ — X? J /' j — ~ — j ? /_ ~ ! /' j K ' _ ± J j W 7j / ! ± _ J — j ? / _ ± j %±jKX=j° 9 ? ~ [ ? h 4 ' j ±j = ^ /= _ ± K = ' ~ [ ? _ = _ !^ ? K /X~ ? ~ ! /' j 7j / j ? j ±J ° h x / ~[ j ? j ±J Xj = * /' j w B - X= =jj? /~ X— % ±~ ; j /' j 7j / ± j = ~ ^ /X~ ? >° < zc1+h x = /' j j?j±J° X? K ±j _ =j = * /' j ±j _ /X; j X— % ±~ ; j — j ? / = ~ [ ° W j K ±j_ =j = * /~ E vW AXX _ / mgss k j 1 h 4 'j — _ X? ±j _ = ~ ? !~ ± /' X= X= /' j !_ K /

■"* X° E

X a c

~h'X smc r >J 8sc

pLD5!E±_ v Ih 4>j 7K» j~j±%° ±jX~z^!X~U < 1 _ !^?±_K/!X ~ ! j~K±7±°* ~!Kj^??X ] < N— 0 ~ !% Y X? _ /'j w?j±J° B~[U - j/'~W T/>j > > K pp|v■_C £■■un Y c p£ m p* p J^ ■^ ■ ] ^ J < y_)^"■¥kpk] ■ pp■( < $— N 0—NRvN<N£q j; j ? (D />j W ^ > _ W K ^ ? j h B ~ ± K^ — 7^ — ~ _ h ■, k —N a<£vNNS <q ~ / 7 h K^KK!]/^^X X X^ ;Y9±!X—j/j± XX J eCj_ X ZLx gx ) />K T)/8[XX K^±;j/

/' _ / /' j 7j /= >jK~— j X? K ±j _ = X? J ° K ~ X— _ /j W _ / ' XJ ' j ± j? j ±J Xj = * /' j = ~ [ ' _ W ±~ ? XK ! ±_ J — j ? /= /' _ / _ ±j = [ j % / _[ _° >° /' j — _ J ? j /XK !XjW ±j % ±j = j ? / _ W j K ± j _ = X? J !±_ K /X~ ? ~ ! /' j 7j / j? j ±J ° h 4 ' X= — _° _ = ~ > j X^ = /±_ /j W >° /' j !_ K / /' _ / /' j ±j _ / X; j ± j = ~ ^ / X~ ? X— % ±~ ; j— j ? / _ K ' Xj ; j W [ X/' /' j w B -

mcn


111

(JI

.... ~I.J)

0 •l ll"fl () ~tHI .11,) t(O

ft:I ... tf'Jl I _. .J ,

I-:! :o ~ ~~""r.bu~cu t".:r :uiJ l.r:1w· ~"'' .ual ~J.J UC\' 1 ~, _i,:u .n" L[l' i.;i."t-:ctur . . ,.it:t .1J=ph .. :.1.t.J.1a .!I :he £pa~ FV,,ti, ~:i.:~:. R...~uth, .Jf. •ut:.uLLulU ~'IJ' .t:c-J lfl ~1.&.J Ln th: h:1.l

,1gn.1l ua.. foun.! b~ .i.:m.:ni:i;i ,l\Cr .ill fragm<.--:11~. Jj foi!o,... ;._

E.umplcs oi the rewlun~ -11;mai dL,tnb,m.>n.. .uc: iho1\n :.., F~ Ill. for 1 = 6 1.::ts. ti1': roulU.!ion \\:l.S

founJ to be: ~-3''·• at IUO GcV .1.nJ 6.6• • . 11

500 Ge\'. C.1mpar::J to the n:,w.,lut1,m that ~:, be expa:tcd frnr:i the cal.mt:OC"".cr s~,1cn1 .1."11:-c. th~ rcpreic:nu :i rc:.111\c Ullpro•,c:ncnt .:if 13"·• and 19•-~. r!:ipc,;;tm:ly.

We bJ.,c !Uuuicrl the clTa:ts of the EF\.I o-.cr ;i

1\l<l.= r:i.ugc oi eoc:rgics. W.: oil!.u ~.m.:t.i tile p:irametcr t!ut ddincs thc jct t,pe (%). " v.ell as the m-1mcnwm thrc'llw&d for the dwinction between ludrons or typo fb) and 1.::) ip?a:)- The: results are ,uflU?Uro.ed in Fi~ 11 :ind 11.

Fii;. II sho111s 1hc calorim;tric jct ~olutioo of the f!1:ncric LEP o.!ct.:ctilc tthe dashed llne). :u v.dl J.S the jct resolution ooc might expect 111hcn .!ppl~ing the EFM to jc:ti mcasurc:J "'ith this ..!ctc:-.:t.lr, .i~erummg Lie momenta of tl:c d-..arl:,'C.i jct fragmctt are pra:isc:ly lulollln. The rcsuJu .l!'e sl:Olm u .1 funct:on of the jct c:1Cig:,. At low cncrgic:s.. the EF:\I is scrn to impnwe t!tc: jct rc:soh:tion b:r .. 35''•. A, the: cncrg~ i:tcrca~. the rclati\'C imptO\C:UClll !>.lo,,_.·ly dc.:!C:UCS.. w - JS~~ at J(J(;O GcV. The IIl.lin rc-.. son fat this i.i the f:1.:t

153

~

,. ~ .... .,., :i ~

lfl.' ~· ~-----~-------i

I' ·~ . I

r

I .: . II) f

I I ,

' f r I ' IJ

''-~ 1) 15

------··· • ~,~ ·.t,-! 0

1

---.,i1: ,,,;,,f • , ... • f'9frt• rl,.u ·-~•:Ou(

..

0.10 UI~ {I

-11/E h~ : ! . TIit JC1 <D<fP1 ,....,1u,1u<1 .u ~ (WK"!l-'I .,,- ~.

.ih~nd .&ftcr "J'l'•'i~ dk, Ener~v F].,.. M<th.l.! Ube bl:.:11 Jue, J. .,...,~ :..aual.,tai .i..1.1 fr.JC1 ,. ~.nu:lcr ,. .dl .,, _.,, fl:l.:.ftlt)o)CI p,:n h\• lb:- c.i.bod =r.,e. FJr ""m.p.lO"'°- the _.:1 fl:l<>lut.JII ul .t .:o>a:p,ra;uif>! c.ik,r.nu:1"r is 2t>Ca I SP ACAL{~~ tbo: J.,u...-J .:unci .

that the jcu become mcrea,;.jngly oolLimatcd at higher energies. the iktw tudronic fragments that arc: swept a,,_.a~ b~ the m.i!,[octic Ciel,.! rcprc:scnt J

ckl::reasm~ rr.ictfrln or the jct cnerg:,. Tht1 tna> also be: illu~1ra:cd b:r the fa.:t that the rdati\•e rc.oluti<>n improI.::ncat .:u:hiC\"cd with the EF:\I

cB H U Xx "^? N < [ x ! j / 9 ; ± >RS N*Rq NR L O h 1 Y ± x / X X X » L ! j ^ ^ ; z > ^ ^ ! / z > Y u 1 c e j:}E$■ idz U i z ,

w?j±J° TgK1V # ■

[ ' C

E= ms ^

dT U T9 U v T Xj 1 h9 ’ » E / / h % Ph E z Q j 1 U ’ 8 E Ulh % E n kj11K 7 / X < z E B 1 £ v k j1 hd

±<X±U=h9 P

X

h CP ;

# d1wU&6 6 E*wUZgU ) »1 ) E un U /hA * m U 6 eEUUW2"fX3ilih w U© qUUU 7 F g , B L Z^ 7 ’ _ ■ x +%; E 4 gX!X1hK

AQ]EQ A

U U = E

X>X

lm ,Q'

E vi1w

BXjh e i h 0 j / XK j h _ X% ± _ Xj ? ^ ? / 7 ’ D/Xj ojX ± ± / ~ /^ ^ — >° ^— \ e'K 4 ^ ± X ? B _ [ -.Xm[—K _ = 7 v A^ X= ± /[ ? ~ ! 4'j j / KK;_J° 0 j X^ X? h_ - ~ _ /j g _ ~ [o±X7Ezh♦XXXXXh l he! ^ z /K ±— X %_±_~X±/j! X'~XKhUY 4'j -hhhm R * ^ <* % ' _j±_ ~^h\9Cm vX; ±^ [±hK;±^ê __e_ X'j g , B -_K vh D4Y±_gK — X^±EK_XEX±h Zjj X ? o X^± ^KXjz;

X? K ±j _ =j W [ X/' /XK — ~ — j ? /^ — /' ±j = ' ~ W i1 E _±hW [ X/' /' j ; _ ^ j ~ ! U m m f r 7j /= K ~ ? /_ X? — ~ ±j X~ ! / % _ ±/XK j = /' _ ? _ f n ~?j='h 4 ' j j ± ± ~ ± > _ ±= X? B XJ h mm X? W XK _ /j /' j KX4KK/ ~ ! /' j K ' ~ XK j ~ ! /' j 5 % _ ±_ — j /j ± ~ ? /' j ±j =^ /= * _ ? W [ _ = m k j1 h ± — /' j =j = X— ^ _ /X~ ? = h

B XJ h ma ='~[ U ' ~ [ /'j X— % ± ~ ; j — j ? / ~ ! /'j j ? j ±J ° ±j = ~ ^ / X~ ? /' _ / K_? > j _ K ' Xj ; j W [ X/' _ / ± _ K 9 j ± /' _ / — j _ =^ ±j = /' j — ~ — j ? /_ ~ ! W Xj K' _±J jW 7j / ! ± _ J — j ? /= W j % j ? W = ~ ? /' j ; _ ± X~ ^ = % _ ±_ — j /j ±= ^ =jW X? /' j = X— ^ _ /X~ ? = h 4 ' X= X— % ± ~ ; j — j ? / Kj_±° > j ? j!X/= ! ±~ — _ = / ±~ ? J j ± — _ J ? j /XK !Xj W * [ 'XK' X= j * ^ X; _ j ? / /~ _ _ ±J j ± ;_ ^j ~ ! !u, TB XJ h ma_'h 4 ' j > j? j!X/= ~ ! /' j w B - _ =~ ' _ ; j _ /j? W j ? K° /~ W j K ±j_ =j [ ' j ? _ > j / /j ± j _ ~ ? — j /j ± = ° = /j — X= ^=jWh 6 K K ~ ? K ^ W j W /' X= ! ±~ — = X— ^ _ /X~ ? = * X? [ ' XK' [j ±j % _ K j W /' j K _ ~ ? — K /j ± 7 7 ° ~ ? j [ X/' _ ' _ W ±~ ? XK ±j = ~ ^ / X~ ? ~ ! nU+ _ ? W j op /f m hn hQ ? /' j ~ /' j ± ' _ ? W * /' j° X?K ±j_ =j [ ' j ? _ — ~ ±j X? !j ± X~ ± j _ ~ ? — j /j ± =° =/j— X= ^ = j W h 6 K K' jK9 jW /' _ / >° = X— ^ _ /X? J _ K _ ~ ±X— j /j ± [ X/' _ ' _ W ±~ ? XK ±K = ~ ^ ? ~ ? ~ ! vgq41 G k L qR _ ? W Ki4/ f ahsh 4 ' j = j /j ? W j ? K Xj = K _ ? > j ^ ? W j ±= /~ ~ W >° K ~ ? =XW j ±X? J

/' j j] /±j— j j_ =j = o B ~ ± _ % j ±!jK / K _ ~ ± X— j /j ± * /' j ±j X= ? ~ /' X? J j !/ !~ ± _ /±_ K 9 j ± /~ X— % ± ~ ; j ^ % ~ ? * [ ' Xj !~ ± ?~ K _ ~ ± X— j /j ± _ / _ h /' j / ± _ K 9 j ± = /X J X; j = _ ns“h* ± j = ~ ^ / X~ ? !~ ± /'j 7j /= TZ j K /X~ ? nha'h q ~ [ j ; j ± * _ = K _ ? > j =jj? !±~ — B Xj h m a > h !~ ± /' j /' ±j j =°=/j— = [ j = X— ^ _ /j W /' j W X/4 K±j? Kj= _ ±K ±j _ /X; j ° =— _h

RWg hW kq!2;U62Y^*V m*^*v? ~ ±W j ± ? ~ / /~ ±j ° j]K^=X;j° ~ ? - ~ ? /j g _ ± ~

= X— ^ _ /X~ ? = * [ K _ = ~ _ ? _ ° = j W =~— j /j = /> j _ — W _ /_ /_ 9 j ? [ X/' /'j g , B L ^ J 8 % J ±_ W j K _ ~ ± X— j /j ± Dmu V* 4 ' X= K _ ~ ± X— j /j ± K ~ ? = X= /= ~ ! /[ ~ = j K /X~ ? = * [ ' XK ' [ K [X _ > j w - _ ? W q x , h 6 j ^ = j W /' j =j W _ / _ /~ >^ XW ♦A X> ± _ ± Xj = N ~ ! 7j / = XJ?_ W X = / ± X> ^ / X~ ? = ! ~ ± 7 j /= ~ ! _ ; _ ±Xj /° ~ ! j?j±J Xj=* ±_ ? J X? J ! ±~ — n s E m s gs k j1 h 4 ' X= [ _ = W ~ ? j _ = !~ ~[ = DmcVh

z j / !±_J — j ? /= [ j ±j =jj K /jW _ = > j !~ ±j _ K K ~ ±W X? J /~ _ !±_ J — j ? /_ /X~ ? ! ^ ? K / X~ ? ~ ! /° %j T m ' [ X /' a f r * [ ' XK ' /= !_; ~ ±jW >° /' j g , B W _ /_ h B ~ ± j _ K ' 7j / ! ± _ J — j ? / * [K ^ =jW /' j — j _ =^ ±j W = XJ ? _ W X = / ± X> ^ / X~ ? ! ~ ± /j = /> j_ — % X~ ^ = ~ ± j j K /±~ ? = ~ ! /' j ? j _ ±j = / j ? j ±J ° X? ~ ±W j ± /~ W j /j ±— X? j [ '_/ /' j b*V„;U62^2;

mcu


t:1

Energy I Ge Vl IH) UHl i:m :1:,n oa

.,

.. , ,--------,.----..---,

' !U -•

j • <t s ~ Pl-.. • I Cic\',l t 1 ! . tt - ~ p., - i '""""'"' ' • u - .,,_ Pt. - ,] Ge\',"L'. ; ~

u-J.1'1,..-1 Ge~·-'< I i ---------· ' - ~

j~ -.,..i ;,.;~. (.-;,;; . . •• <YI<• .Jl't,", t: • N . '._. c,.,~ :,ocr;..,· E .. "''" I •cOFl"!uf ! _ci•'1-P.-...-:~\' . .:

"i '~ L -;;

... " ~ ill

(I --------------1).:r (l.lO 11 i,:v •un

1,ii,·E

F1~. ::. Rd.Ir.:,~ .a:..prl)ll'!:.Cnt Jf r.~ ·tt ~lQlr:,.,..,n t,i w,r • .1 :he [r.&rl!'. 1-l..i• ~Ceth..k!.., .u ,1 fur....:r....,11 u( ~f'oz :<1.:~ R.e,,utn ,A· ~(,ia,tc!

t"~t" iw!':u..i:,,., ... ~~=h J.tkrmt r.ir:i.~t'f' -.:~-:-;. ...... · The -~L:.a ~ .. ~~ ..... "l&.1 .. '4CI~ ~w.,--..~ ~R:l ie.l~.l~ .:o1.:a ;; .. cc ltk:' l IJF 11w; L 1'1!.r.u!c .:u!.,r.c:.-:lec. S.:c l.::<! 1.,, u:uJ1.

in.:rc-.uoJ ~1th the mLimcntum thtc:shL>IJ /.\..- ar.tl witlt the \J.l:u; uf :t t x = t, JCU .:on:.un m,w: wft paruclo t.~n :t = J onai. Ibc error barli m Fii;. 11 inJ:::-a~c the .:ff.:ct oi the .;b.>1,._,: .:ii th.: %

par:unctcr on !.he results. and Pia. ~a. I GeV .' c m these mnufat.Jons.

Ft~. I:? ill&>\\~ how the: unp.o\erocnt of the energy rcsoluuon lh:u can be: :w:hic\·o.i 1mh .1

tr-.i.:J.cr tb:11 mc-.sliurc:s the momCllU of :he i:haq,."CJ _ict fr.1gmcm.s JcpcnJ,i on the \·;iri.>u.s par:1Jl:c'ler~ used in the simulations. Thu imprO\etncnt clcarl~ bc:udits from a stroni,,'CI' magnetic iidJ. "'hich i5 Cljui\alciu to .a lar1:cr ~:ill.IC of Pt,; (Fig. !:!a). The bcnctiu of the EF'.lrl i1ls.> lu~e :i tco.!enq· to Jc:crcas.c when a b.:ttcr calorimeter s~ stem i:s used. We c.lnclud.:J thl$ iron1 simu!.nio~. in which we rcpucod the c:1lonmctcr b,· one "with a Jui.ironic r=luti<>n of -0%,' ,/£.:. 3'·~ and !!/ft= 1.3. On the other banJ. the~- i.Jlcrc:lic when a miJrc interior c:il,>nmctcr S}Stcm is used. We cha.:kcd that by sunularing a cal.or:mcti:r with .1 hatlronii: CC>cl!UOllQ of l01.l"'o,i ,/£ - g•:.:, and r!,1ft = ~0. Th.:sc tcndcncic:s .:-.m be understood b~ .:onsiJcring

154

the c.urcmc ..:aso: For a pcn"a:! 1:a!O!'imcti::. there i:1 no>t,'lu!g ldt for a 1::1.:k::- tu m:pro,-:: upon. ,, b1lc for no ,~er .1t .ill. th.: i:a.::J.er -.tu! e'l''C:S a JO•,, n:solulion for the jct'I (Section 11). H.:>wc,-cr . .n can be ~D from Fl!,!. 11~. for the rhtcc s~!>ti:rns \>C !llmulat.:d the dJ!Te:cz:.:e:i .:ire rclamcl~ wall.

J.-1.2. £rpcrtm<-nWI dutu In oro.!..--r not to rcly C'(C(u'lr.eiv on M.>ntc urlu

i.Ullul.itions.. \\C :ii.so :m.'11:rzcd some tcstbcam dat:1 ukcn with the: CDF Plui Upgrade c:uorimctcr [l-'J- Th~ i:alonmctcr cunsi..ts .:if t11,o §1:\.°tions. \\bich we \\'ill label E:~1 and HAD. We used the:!.: Jau to build "libraries'· of jct iignal distribuuon.. for jct~ or ;i ,·arict} of cner;;.ta. rangin~ frnm ID-IOCO GcV. Thu W:ts dooc ;a follu\\-:i [ 15J.

Jct fra;;ment, ..-.ere :1ekctc:J .u before aL"l:Druini; to a fra;;mcn1ation funcuon .:>ft)pc: (I) with :r = 6, whw:h IS fa\'orcd by the COF d:l.u. For =11 jet fr:1e'lllc:nt. ,,c used the mca,iurc:J .sign.al Jistnbuli.:111 for ti::st~m ptolli or dcctroru of the o.:-.ueit cncri;) in order to determine ,,hat the ,·ulorv1ll!Ur

J d*)U’6 *^ *U O ■’*V^*; \Y^^;’6*Y* * Y [ w*U—*D( *^ d VUG [V3[ >:’*;^— W^ _ ; 7 ■ dUUVd . .V ♦ iz /;

U:[U’;3 [ ~^ W ' _ ; j > K K~ ' _ W /' _ / ! ± _ J — j ? / _K /^ _ ° W j % ~ = X/j W X/= j ? j ± J ° X? /' j K _ ~ ±X— j /j ±h

B ~ ± j _K' 7 j / ! ± _ J — j ? / ^ ;;//' j? j ±J ° " * * [ K ± _ ? W ~ — ° % ^ j W _ ? w - = XJ?_* _s U* _ ? W _ q x , = XJ ? _ * ± X Uz * ! ± ~ — /' j K ~ ±±j = % ~ ? W X? J = XJ ? _ W X=E/± X> ^ / X~ ? = ! ~ ± _ /j = /> j _ — ±^? ~ ! j j K /± ~ ? = T X ! /' j ! ± _ J — j ? / [ _= ? j ^ / ± _ ' ~ ± % X~ ^ = T X ! /' j !±_J — j? / [ _ = K ' _ ±J jW ' [ ' ~ = j j?j±J° [ _= K ~ =j = / /~ /' j j ? j ±J ° K _ ± ± Xj W > ° /' j 7 j / !±_J — j? /h B ~ ± X? = /_?Kj * ! ~ ± _ ms k j 1 K ' _ ± J j W 7j / !±_J — j? /* [ K ^ =jW /'j j ] % j ± X— j ? /_ = XJ ? _ W 8 /±X> ^ /X~ ? = !~ ± _ ? nhr k j1 % X~ ? /j = /> j_ — ± ^ ? !~ ± /' _ / % ^ ±% ~ = j h 4 ' X= 7j / ! ±_ J — j ? / [ _= /' j ? _ / / ± X> ^ /j W _ ? w - = XJ ? _ G1!® f T m s i t hr > N _ ? W _ q x , =XJ?_ Z N U f T X , i Z h > Y h ±j =% jK /X; j ° h B ~ ± _ ms k j1 ? j ^ /±_ ! ±_ J — j ? /* /' j = 7 — K % ±~ K j W ^ ±j [ ~ ^ W >j !~ ~[ jW * > ^ / /' j =XJ?_= [ ~ ^ W >j /_ 9 j = ! ± ~ — _ ? j jK /±~ ? ±^ ? ± _ /' j ± /' _ ? _ % X~ ? ±^ ? h g ' _ ± J j W ' _ W ±~ ? = [ X/' j ? j ±J Xj = >j~[ = k j 1 [j±j _ = = ^ — j W ? ~ / /~ ±j_K' /' j K _ ~ ±X— j /j ± _ ? W h /' j ±j !~ ±j h /'j° W XW ?~/ K ~ ? /± X> ^ /j /~ /'j j _ ~ ? — j /j ± = XJ ? _ = h

4 ' j Wj=j? !KjW % ±~ K j == [ _= ±j % j _ /j W !~ ± j_K' ~ ! /' j U ! ± _ J — j ? /= /' _ / — _Wj ^ % /' j 7j / ~ ! j ? j±J ° k'( W 4 ' j j ? j ±J ° /' j K _ ~ ± X— j /j ± [ ~^W ' _ ; j ±j K ~ ? = /±^ K /j W !~ ± /' X= % _ ± / XK ^ _ ± 7j / /' j ? X= = X— % °

[ ' j ±j hm _ ? W T W j ? ~ /j /' j K _ X> ±_ /X~ ? K ~ ? = /_ ? /= ^ = jW /~ K ~ ? ; j ± / /' j = XJ ? _ = !±~ — /' j w - _ /^ q x , K _ ~ ± X— j /j ± = K j ^ ~ ? = X? /~ j?j±J Xj=h Z ^ K ' >GL =XJ?_ X> ±_ ± Xj = [ j±j J j ? j ± _ /j W ! ~ ± j_K' ~ ! /' j K ' ~ =j ? 7j / j? j ±J Xj = h

B ~ ± _ J X;j? 7 j / ~ ! _ K j ± /_ X? !X]jW j ? j ±J ° h j hJhh mss k j 1 h /' j j ] % j ± X— j ? /_ % X~ ? = /J ? _ W X= /± X> ^ E/ X~ ? = [ j±j ^ =jW /~ W j /j ±— X? j /' j K _ ~ ±X— j /j ± = XJ ? _ = >[n9 _ ? W >DnM= TX? /' j w - ^ ? W q x , = j K /X~ ? = ' !~ ± X? W X; XW ^ _ K ' _ ±J jW 7 j / ! ±_ J — j ? /= !~ ~ [ X? J /' j = _ — j % ±~ K j W ^ ±j h 4 ' j=j = XJ ? _ = [ j±j _ = ~ K ~ ? ; j ? j W X? /~ j? j ±J ° ^? X/= ^ = X? J /' j K _ X> ±_ E/ X~ ? K ~ ? = /_ ? /= c _ ? W TW 4 ' j /~ /_ K _ ~ ± X— j /j ± = XJ ? _ !±~— /' j 6 K ' _ ± J j W K ~ — % ~ ? j ? /= ~ ! _ JX;j? vgQ k j 1 7j / [ _= / ' ^ = !~ ^ ? W _=

N v=.U c Y ’E ' h 7# EEEEEEEEEL[[&] Tc'

*; 0 l q

_ ? W /' j K _ ~ ± X— j /j ± = XJ ? _ T~ ± ± _ /' j ± X /= j? j±J ° j * ^ X; _ j ? /' ±j % ±j = j ? /X? J /'j ? j ^ /±_ 7 j / K~ — % ~ E? j ? /= ~ ! ~ ^ ± vgQ k j 1 7j / T " Q4m' [ _ = !~ ^ ? W >°E = ^ > /±_ K / X? J kuL**U ! ± ~ — /'j _ ; j ±_ J j ; _ ^ j ~ ! /' j

W X= / ± X> ^ / X~ ? ! ~ ± mss k j1 7j /= h B X? _ ° * /' j j ? j ±J ° ! ~ ^ ? W [ X/' /' j w B - !~ ± /' X= % _ ± / XK ^ _ ± 7j / [ _= K _ K ^ _ /j W _ =

Tt '

[ ' j±j k' Tv f m ha — ' ±j%±j=j? / /' j 2q*U^ » EK ± % j = ~ ! /' j K ' ~ =j ? m^*;L[Um 7j / !±_J — j ? /= * X?K ^W X?J /' j =~ !/ ~ ? j = =[ j% / _[ _° >° /'j — _ J ? j /XK !XjWh

4 ' j ±j _ /X; j j !!jK / ~ ! /' j w B - ~ ? /' j 7j / j?j±J° ±j = ~ ^ /X~ ? [ _= z K /K ±— ^ XK W >° K ~ — % _ ± X? J /' j ! ±_ K /X~ ? _ [ XW /' = ~ ! /' j > W' ~ ±_ W X= /± X> ^ /X~ ? = h 4 ' j X— % ±~ ; j — j ? / ~ ! /' j 7j / j?j±J° ±j = ~ ^ /X~ ? !~ ^ ? W /' X= [_; X= X? K ^ W j W X? B XJh ma>h 4'j W _ / _ _J ±j j [j [ X/' /' j ±j =^ /= ~ ! ~ ^ ± = X— ^ _ /X~ ? = !~ ± _ K _ ~ ±X— j /j ± ;°=/K— [ X/' /' j % ±~ % j ± /Xj = ~ ! /' j g , B ~ ?j h

y ~ /' ~ ^ ± = X— ^ _ /X~ ? = _ ? W /' j j ] % j ± X— j ? /_ W _ /_ ='~[ /' _ / /' j w B - W j j = ~/4K± _ > j? j!XK X_ j!!jK /h q ~ [ j; j ±* /' X= j !!j K / =' ~ ^ W ? ~ / > j j ] _J J j ±_ /j W h 4 Xj X— % ±~ ; j — j ? / X? /' j j?j±J° ± j = ~ ^ /X~ ? _ /° % XK_ ° 5vEUUh L ~ ~ ± K _ ~ ±X— j /j ± = ° = /j — = >j?jk / — ~ ±j /' _ ? J ~ ~ W K _ ~ ± X— j /j ± =°=/j— =* _ ? W _ = /±~ ? J — _ J ? j /XK !XjW _ =~ ' j % = h v/ X= X— % ~ ± /_ ? / /~ ? ~ /j / ' _ / /' j w B - W ~ K = ? ~ / [ ~±9 _ = [ W _ / ' XJ' j ? j ±J Xj = _ = _ e ~[ j? j ±J Xj = h 4 ' j ±j !~ ±j * /' j n/XR X— % ±~ ; j — j ? / — /' j — _ == ±j =~ ^ /X~ ? ~ > /_ — K W !~ ± ' _ W ±~ ^ XK _ ° W j K _ ° X? J " AU _ / ) w L X= % ±~ > _ > ° _? ^ % % j ± X— X/ ! ~ ± [ ' _ / — _ ° >j j ] % jK /j W !±~ — /' X= /j K ' ? X* ^ j _ / _ ' XJ ' Ej ? j ±J ° ) X? j _ ±Eg ~ XW j ± j ] % j ± XE— j ? /h x / ' XJ ' j ? j ±J Xj = * /' j ' _ W ±~ ? XK j _ ~ ? — j /j ± ±j = ~ ^ / X~ ? X= W ~ — X? _ /j W >° !^ K /^ _ /X~ ? = /' _ / ±j =^ / ! ±~ — /' j W X±4 K±K_/ K _ ~ ± X— j /j ± ±j = % ~ ? =j /~ K — _ ? W ? ~ ^ EK — j? j±J ° W j % ~ = X / h 4 ' j = j ! ^ K /^ _ /X~ ? = _ ±j ? ~ / _ W W ±j = = j W * ? ~ ± K ^ ±j W >° /' j w B - h

B ~ ± K ~ — % _ ± X= ~ ? * [ K ='~[ X? B XJ h mm /' j 7j / ± j = ~ ^ /X~ ? — j _ = ^ ±j W [ X/' /'j Z L x g x ) K _ ~ ± XE— j /j ± Dt V* 4 ' _ ? 9 = /~ /> K K ~ — % j ? =_ /X? J K ' _ ± _ K /j ± ~ ! /' X= W j; XKj * /' j 7j / ±j = ~ ^ /X~ ? =K_j= ;j±° [ j [ X/' " E m 4 ' X= ! j _ /^ ±j * K ~ — > X? j W [ X/' /> j W X— X? X=' X? J ±j = ~ ^ /X~ ? X— % ± ~ ; j — j ? / _K' Xj;jW [ X/' /' j w B - _ / ' XJ ' j ? j ±J Xj = * X= ±j = % ~ ? = X> j !~ ± /' j — ^ K ' > j //j ± % j ± !~ ± — _ ? K j /' _ / — _ ° >j j]%jK /jW X? /' j ' XJ'E j ? j ±J ° ±jJ X~ ? h

mcc


$1,Jr...U \\·ould ba\'c been tuJ tlut fr:i;mc:nt actu:1Uy Jc:positcd it." energy in the c:i.lorimc:tcr.

For Cllcll jct fr~"fflCDt l \vtth cncr£y £,. we r.mdumly puUi:J :in Bl ,n;;na.l • .12. and a HAD s.ign:il. Jud. from the c-orrcspondin!,! signal o.!i:1-tributi.->ra for 3 tcstbc-Jm run of da:tro~ r if the fragment was i:cutrJ!) or piol!s (if the fra.1mcnt \\:l.i cha!~C\!) \~ho~c c:::ic:rl,!} wa.s doscst t,l the energy .::irri,=tl by the Jet fragmcnL For msun,c. for .1 IO Ge\' cbar,,,"CJ ,ct ir:l!,'lllCOL 11,;; U'5CJ the: expcrimcnul sign.ti .:i~tnbuttv0$ r..,r :in 3.6 GcV pi,1::1 t.....,,tb.:-.t:n nm for :hat purp.1s.:. This jct fr:i_!!rec:tt "a• then atm!)u~cJ .1n E...\l ..i;!!Ul S';"' = 1 l0-·S.6)i:a JnJ a i-L.\D ..:1,'!lJ.i s:LJ = 1 :o.•s.oi?·..i. ro.pcl:t:,d~. F~,r J lfJ Gc:V ncuttai fra£mcnt. the ~.unc p:Ol:~-Jurc w-,uiJ be follcmeJ. but the ,1~na;i \~ilulJ be ulcr. from .in ct...-.::roa run rather th.1:1 .1 pion run. Oi.ari;cd h:id:L>m w;th c:ni.:rgic::s bclow .:! Ge: V 1\e:: .ait:rr..::d not :.> rc-.ich L'le cak>rimc:cr an<l. thcrcfmc. lhe~ diJ 11,,t .: .. ,nr:it,,..rc to the c.1!.:,nn::.::cr st~:a!-..

The t!i:scn!:cd pro.:ess ~as rc:pc-.1t.:,l for each of :r.c II fr.1=,m.:nu th..t: ma.le up :he JC[ of c:nc:rL"- £.~. fhe enc:!!• the ca!.1r:rnctcr w1..,uld l:a,·c-·,i::.~~,truL"!Cli for-~l~ parti\:uLr ,:t then L',

~imp!~

1.;)

,~here A o1nd B denote tbc calibrauoa constan~ used LO CL>tl\c:n the~ from the E.\l a.ad HAD caklrll"..cti:r sa:uon.s totu cnerg.ic:i.. Such .S:,:, .ign.11 Jibr.1r..c~ \1,/C:r.: gcm:r.1 tcd for c-.. u:h .-,r tbc c.'wsc:n jct eocrgics..

For a ~\en jct of a cawn fucd c:ncrgy. c:.i;_ !C.1J Ge\'. toe: cxpcrimcnul pion s:gnal di.itribuuorn1 \\Crc ll!iCt.i tll Jctc:rminc th.: calorimeter s.ii,;1la.!s ·5:1" anJ S:,W Cin ti-~ Bl and HAD ~o::lions) for mlli~iJUJI d1ar0"C\.I jct fr:1;,:mcnts ,'. foll.:,.,,,, i:ig the !I.I.me pro,:ai:.ue. Thoe ugnab "·c:c: als.:> cOO\'ctt.:d mto energy uruu 11.img t!tc c.1hbt:1· uon c: .. ,rutant. .-t ;sn,d 8. The total c:li.->rimcti:r sii;n.il from ti1c m durgeJ c:omponc:nts of a !,'i•·cn IOil GcV jct 11;.i.,i thus founJ ;is

.. r~ s.r---11 £.i..,!Dl = '>" ,·-· - -j· ~ A B ,- ..

155

119

.llld ~ calorimeter st~ \or r:ithc:r its energy c:qut\·alc:nt) rcprc:si::nting the neutral jct oomponellts of our ll'O GcV jct (£,,.,JtJ v.:i.s fouoJ by subtr-.u:ting E.;1,w,...i from titc J\cr:ig,c: ,·alue of r.hc: s., d:.mihuti.:,n · for JOO Gc:V jc!S.. Finail). th.: energy found 11,ith the EF'.\.1 for this p.-irtkular jct \\;LS .,"aJ.:Uutctl .lS

"' £EF\I "' L E, - £=,

,-1

(6)

wb..--r:: E, 11 = I.:, .... m) rt?rocllt the .-x.ilf enc~..._ .:i( thc .JlLJS..:!l dtllr:;d Jct {ra~L" md.1..!!!!;? the .>0ft or.c:1 ,wc:pt :1·.,,a~ by rhc magr..:t:c :idi.!.

T.1.: r::!.1ll\c ;ff .. -.:t of the EF\l 011 the Jct C:lcr~~rc;.oh!t:..,n wa.~ ..!r.::cr:nui.:tl hy c.1mp:1r:ng the fr:t.:t;.:,n.il v.1dlli,i .ift:tc .,·,== .. r..J £ff.,. <!i,mhuu.in,i. The 1mprn~emcnt of the JCl c:oa~· roult:twn focn.! this >1<'1} 15 i:tdud.:J m Fi;;. l~l>. fb: ..!ata .1,r--1:1: v.c:l! "1:h th.: co.ult!> ._,f uur ,~u!.tu-,n,i fot a c.1l0nmc:.:.:r •) s:cm "uh the r,ropcrt:o of :.!>c CDF .inc.

Both •.>ur ,1mula:1ons J!IJ th.: cxpcr1mi::1t.1l t.l.!t.t i.':o,~ :bat :r.c LI \l Jc-,.;:\ utT.:r a bc:tdi.:i.11 cff:ct. Ho>1<C:\Cl", 1h1,; cllcct ,h-1ulJ not t,c o:i~:--=ratcJ. r.1e im;,rmo:icut 111 the cna!l} rc:,;olution ts

t}pid!) 30•· •. Poor ..-alorim.:tcr •)'-tern~ benefit Clacc tlt.u1 goo<l .::.:uorimc:tcr .ij!ltcnu . .1.nJ a stro:1g rr..a~r.cuc :idJ .11>0 hdp,i.. It 1s !Dlportant :-.> :ia:c that the EF\t Joes not "'orll as wdl at hi;;h c:ncr1,'lo as a: Jo" energies. TllC!'Cforc. the 3-0~'• l!llpru,c~:nt m the ITU'-S rcsoh,t:on .lbtamcd for h;.1droux-ally Jc,.":lytcg Z', :ll LEP is proh-.1bly ,m u;,pc:r limit for what may be c::1.PQ:tcd from th:s 1c_ !1:1,-1uc .11 ,1 hi~..:ncr£} Llncar-Collidcr c:1.pcrinxnt. At high cr.,crgi<:s. r.hc: h:uuonic 1.."!ll.mm .. ""!c:r n:s.olution i5 JominatcJ by ductu:iuons th.it result from the Jiffcrc:nt ..:alorirr.c:tcr rcspon~c to cm .1nJ nou-cm c:ncrln' .!cp..lsiL These tlu.:tuations arc: not JJ~J.. nor .:urcJ b~ the EHi.

ror cllmparuon. -.i;e Jlllw in Fig. 11 tile jct r=lution mc::isurcd \\ith the: SP..\CAL cil-.>nr.:ctcr (!<J. Thans., to :.be: comr,c11"'1ting ch.ar-J.:tcr or this .i.:,,;.:c. the j:! ro.oluuon 1ea!cs ,cry ...,di ·,1,irh £- 1 • ~. Tbt.s feature. oombinc:J with :be d.!miuisltin!; n:soluuoo :mi:irn,cmcnt :1d1ic\cJ with Li..: .EF\{ Jt

h:gh cn.:rgi.:s. is rcspon.-.iblc: for the much better performance that m.1y be o.pc:ctcd in the h:;;hcncrgy rcgi.:in.

cB pN<]vS N N *Np . WN€<5q0 >qR_*Sq 6 uN<><EN _/ z♦!K;±/K± aqNq%N v :N( /GU;^hUm uEZ*[Eb

uh g~?W_=X~_X

_ /' ^ % _ % j ± * [ j ' _ ; j = /^ W Xj W =~ — j ~ ! /' j !_ K /~ ±= /' _ / X—=/ /' j % ±j K X= X~ ? [ X/' [ 'XK' /' j j?j±J° ~ ! ! ±_ J — j ? /X? J * ^ _ ±9 = — _ ° >j — j_ =^ ±jW h 6 K !~ ^ ? W /' _ / _ / j? j±J Xj= > j ~ [ # mss k j 1 * _ W ~ — X? _ /X? J ±~ j X= % _° jW >° /> K _ J ~ ± X /' — /' _ / X= ^ =jW /~ XWj? /X!° /' j K ~ — % ~ ? j ? /= ~ ! /' j !±_ J — j ? /EX? J * ^ _ ±9 T/' j 7 j / _ J ~ ±X/' — 'h q ~ [ j ; j ± * _ / ' XJ ' j ± K? K±J XK Xh /' j 7j /= _ ±K X? K ±j_ = X? J ° K ~ X— _ /j W _? W /' j % ±j K X= X~ ? [ X/' [ 'XK' /' j * ^ _ ± 9 A= % ±~ % j ±/Xj = — _° 'j — j _ =^ ±j W X= X? K ±j _ = X? J ° W ~ — X? _ /j W >° /' j * ^ _ X/° ~ ! /' j j ] % j ± X— j ? /_ j * ^ X% — j ? /h

6 K ' _; j = ' ~ [ ? /' _ / /' j =~ EK _ j W w ?j±J° B~[ - j /' ~ W * X? [ ' XK ' /' j — ~ — j ? /_ ~ ! /' j K' _ ±J j W !±_J — j ? /= !~ ±— /' j > _ = X= ~ ! /' j °j/ j?j±J° — j _ =^ ±j — j ? /* % ±~ ; XW j = _ — ~ W j = / X— % ±~ ; j — j ? / ~ ! /' j ±j =~ ^ /X~ ? /' _ / K_? > j ~ > /_ X? j W [ X/' = /_ ? W E_ ~ ? j K _ ~ ±X— j /j ± =° =/j— =h 4 ' j ±j _ /X; j X— % ±~ ; j E— j? / X= _ > ~ ^ / n s U h !~ ± 7j /= ! ± ~ — W j K_ ° X? J 6 hH > ~ =~ ? = _ ? W W j K ±j_ = j = _ / ' XJ ' j ± j ? j ±J Xj = h g _ X— = /' _ / — ^K' ' K / /j ± ±j =^ /= — _° ' j _K' Xj; jW !~ ± ' XJ' ° J ±_ ? ^ _ ± K _ ~ ± X— j /j ± = ° = /j — = * X? [ ' XK' /' j =' ~ [ j±= J j ? j ±_ /j W >° /'j X? W X; XW ^ _ 7j / ! ±_J — j ? /= — _ ° >j Kjj~ J ? X±jW _ ? W = j % _ ±_ /j W ! ±~ — j _ K ' ~ /' j ± _ ± K ^ ? = ^ > = /_ ? /X_ /j W h 6 K ' _ ; j = ' ~ [ ? /' _ / !~ ± — ~ = / ~ ! /' j =' ~ [ j ±= X? % ±_ K /XK _ W j /j K /~ ± = * /' j ~ ; j ±_ % >j/[ jj? /' j = ' ~ [ j ± % ±~ !Xj = ± _ /' j ± /' _ ? /' j W j /j K /~ ± J ±_ ? ^ _ ± X /° X= /' j ! _ K /~ ± /' _ / X— X/= /' j >j?j!X/= ~ ! /' X= — j /' ~ W h

x > j //j ± = ~ ^ / X~ ? !~ ± ' XJ ' E% ±K K /= /~ ? — j _ =^ ±j E— j ? /= ~ ! !±_ J — j ? /X? J * ^ _ ±9 = X= _ ' XJ ' E±K =~ ^ /X~ ? K_ ~ ±X— j /j ± =° = /j— h 4 ±_ W X / X~ ? _ K ~ — % j ? = _ /X? J K _ E~ ±X— j/j ±= h [ ' XK' _ ~ [ !~ ± ' XJ ' E ±K = ~ ^ / X~ ? 7j / — j_=^ ±j — j ? /= * _ ± K X— X/jW X? ^^^;U; j j K /±~ — _J ? j /XK ±j =~ ^ /X~ ? h x ? ~ % / X— _ = ~ ^ /X~ ? — XJ ' / > j _ W ^ _ E ±j _ W ~ ^ / K _ ~ ± X— j /j ± Dmr’h X? [ ' XK ' /' j *Y =' ~ [ j ± !±_ K /X~ ? X= — j _ =^ ±j W K ; K? /E> ° EK ; K ? / _ ? W [ 'XK' W ~ K = ? ~ / ±j * ^ X±j /' j =— _ = _ — % X? J !±_K /X~ ? ? jjW jW !~ ± K ~ — % j ? =_ /X? J Wj; XKj=h

xK9[^[ XjXJ±X?j?);

4 ' X= = /^W° [ _= K _ ± ± Xj W ~ ^ / [ X/' ! X? _? K X_ = ^ % % ~ ± / ~ ! /' j 8 ? X/j W Z /_ /j = , j % _ ± /— j ? / ~ ! w ? j ±J ° * ^?Wj± K ~ ? /±_ K / , w EB k s n E&l Xw 0 u s b n Z h _ ? W ~ ! 4 j]_= 4 j K ' 8 ? X; j ±= X/° A= g _ ±9 Z K ' ~ _ ±= % ±~ J ±_ — h

0 j!j±j? Kj=

D e ’ 0 h 6 X^ X^ 7 X_ h g 7 9 — ? X ± / ! 2 # E X ± ^ l ^ X — ] ? X ^ % ^ XK » B<— % ' ° /^ _ h ^_ _ /j ? ^ e X< E K ^ 1 ! X ± h 7 ! - ~ ? ~ j ^ % / ^ £q

1ûh .'rrB T q ! K K / X ) X9 + K ± ^ /; L ?±; Xh a s hsw , Xz;XX4h K/ 7 ) EP 79 ) v XX8 ± ~ _ e - j / _ x cE - xX U

In ’ , y ^z/) !KXeh K / X h h P ^ ) _ ^ ± h j /^ X - j /' h x uq{X=

• / ’ B 8 8 \ K_ h x , - ^ ± X? h 3 /^ ±6 U _ ) E± % K 7— h 6 h j C h PjdU 2 ~ ± 9 h X = - % 8 o

DUT , k X; j ? h g57j/ X% ~ ? ± = ? K ~ % ° _ / Z » ' IX^?~[ - +/;h B = ± ? ^ 9 X>

0 j % = X ± Bd±±±^)7'U/A+U=!UU-l♦ X - h I■UUUlDUl’ Z h8 9 _ ? ^ ^ ) /Xj X h K/ _ X h P ^9z _ _ ± u— mE 5 K /> x 5zQ

d a 8 + X XUehhD4V 1 1 x > ± _ ^ 9 ? h o / .Z h P X9 X h ) ? ^ ± _ ^ X X - W Z / x Ummp Tammsm /

! X ’ , x99U+- hK/ 7) h P X_e) ~ ^ ± K ^ j P ! j X / X } ZX/U X- w B Q K K [ ! h j/ }NBB - Quu 8 ^ ± ] _ K - j /' x l ±! m eZ 6 + z z ! h

X o s ’ 2 / ^ ± K ! j X / / X X / ! ! /' j a)Qv x X A> Ax ~ ± 9 7 X 9 / / ~ !! e > j B ^ /^ ± j K / L _ ± / XK j L ' ° ^ K = * Z ! ] X ? ? ? XU h g Q h x < N p m h agz8vh

7 h ’ 1 X h h - ~ ±J ^ j U U * g x 9 [ ±±_z/±U , K _ _ ? [ /X' w _K— l UB ) l [ g ~ ? K j % / h 4~x % ± K _ — /j W ^ X /' j 8 Z ' ~dK±~~/X) UM z g ~ ~ E

j±=] X^j ~ ? g _ 9 — X? j /? O Z ( X = ' B?j±=±° L'°»XK+ h L X Y X K j = ^ h W ]R E v pn a°h assah

Tm Em , x ^ l U ^ hj / _ / * P ^ W h v — X ± h - j /' h x 8 q / 6 X Oc Tv ’ 4 w Z ) x 4 K;' X9^ Xz , /[ J ~ 0 j % ~ ± / * ±j ! j K / , w Z 2 4/8 q E~ vh

k w Z 2 h q ^ ] X h» ± = h w —01<Rq1B aXx iXhT 8 ’ - x > ! ~ _ h K / _ X P ~ W h 8 ? X] h 71R] - j /' x X » U a 6 a X cau h

T e c V - x > j X /U * —< $ N BB _ / K ± K W X > K / ) ~ ? _ A / > j ) ? 9 / h /^ X X X _ X

» ! / ! — j _ ^ ~ ! 9 _ XK ^ ? K XK ± l ° Y /j _ h P ^ v v? _ X± h n s z - j /' h x u 1 p XAa 8 8 e' nmmh

Tm r ' Z) 6 XJ — X! 9 h T z ^ _ ± /] B X> j ± = ~ ? X /' j L / ^ = % K _ = :£— v ) ^ X ± ~ _ g ~ X~ ? / = j / ± h am / ' j / N E 0 _ ~ x X ~ ^ ) ± C j ) !/KP __=g X? _= ~ !

/ > j Xj ; Aj _ X> _ / j — ~ ] ^ ] ^ g ~ ? 7Xj ±j? ~ j g ~ ~ K — j / ? 7+ v g ] ' w ? j±J ° L ' ° ; K X h 4 ^ K - ? * m Y ip h 6 ~ ±g X Z ± j ? / _ / 9 * Z = _ j X% K K j h % % mma mU'U

mcr


IJl t!w paper. 11·e B:L\'C nP<fied 90mc of the factors that lim:t the pra:L~ort with ,~bid1 the energy of fr.lgmcnung quarks lll:l)' be m=urcd. We founJ tb:u at cncrg1e:1 bclnw .. 100 C,cV. a dor:unating role is pla ycd b)' Lbe .ugorithm that is

wal to i&:ntify the comporu:nu of the fr11gmc:n1-ing quan (the jct J!i;oritbru). Ho11c-.·cr. at higher cucr;;ia. the jcU .:re incrc:ui:1;;.ly collimated J.nJ the prC\:liion ,,ith IVb:ch the qu.:irl.'i ~opcrucs m;i.y he masurcd l~ im:rc:uil1i;ly ,fominatod by the L{Uallt)' oi th,: cxpcr:m!nul cqu1pmer.L

We lb,e ,Jiu~n :hat the ,L><.tllcJ Eucrg.:, Fki\Oo '.l.lcthuJ. m which th.c m.:imcnt.J .:if t,i..: clur~cd fra~'ll'.alls form thc basis .,f the ,=:t cne~i:r.:,· mca.urcmc:n. pro,iJc:s .i mo.lot impro~c:mc:11 of the rcs..1luti0n that can be oh1.uneJ "'1th s!Jr.Jafone calori:ncta s);,t:m.-... The rclathe impro,emcnt ~ abuut jQ• .. ~ for jeL\ fr,lm JcL-a~ini; WL b.:J!k)tU anJ decreases at hig::i..:r cncrgi,:s. Gauus that m:i.:h hct:er r=ilt~ ma> he a.:!11e,cJ for h!J1hly gr:mula: .:a!.ornnetcr •} w::ns. 111 \\ h:c.'1 the d1..w.cr:. i;.:1:.:rau:d by the m<li~1Jual jct fr.1smcnt.s au:, be rci.-ognu.cJ .UlJ scr::irat...--d from each other arc lilUUbstamiated. \\',: have ,ilio""n that for m!Y.>t of the sh.:rners in prai:t1cl ~c.:tor.s. the overlap bclv.ccn tl:.c sbo11cr prorilo. rather than the .kt.xtor i;ra.nul.lnt~ is the faL'ti>r that limit.; the bc!le:ib of thu rncthoJ.

A better s,.:1luuon for high-prei:won =u:cfflCDL!< of frn;;mcntio~ Ljuaru is a hi;;h-rcsolution cawrimctcr l}~tcm. Traditi.:irul ~mpens:mo~ c-.1-lorimcter.i. 10-hi1. .. b al!.:iw for hi;;b-CO<Jlution jct mc:uurc:mc:nts. uc litllltoJ io lhcir c:b:tral?LlgnctlC resolution. All optimal solution mi~t be a dualrCJJour cl.Jrimctcr [161. in y,•hicb thc cm slJoy,cr fr:ictl.:ln ti l'CCllllCCJ C\'CIH-by-<:\'Clt :mJ wbi,.;h J~ oot require the mull -1:?mpling fr.icti.:in ocaicJ for .:£1m('I01."8llng Jc,,ia:s.

156

Tb.is study \\ai orricd out \lllb liruncial support of the linncd States Department ,lf Energy. unJa rontr.ict OE-fGOJ-•.>:ER.;()938. an,J of Ta.u Ta:h l'r.t\CNty'" Clark 'w:hofan program.

(;I ll. 17,,~u:.un. C.luri::...u:,-=<=!.' ·=•»Uttt:X~II ,U pw:.0

.i<: r!i~·= ... L::11,:111.1: ........ 1 ~-rue, ~· )ofon.,~Dfl--' ~a Phuk.'"1. \'uil. ;1r.. (h!~ Cn,,l!'n,:•, P:ru. 1J1.1:,,J. ~,.o

,;I G Cl lf.ur."' JL :'...a.L 111.ir 4&1.: lkt~ .\ ;•111 :,-., i;: [JI C> Du.Jtck <l .&I .• Sud l:uu. an.! .\l,..i-. A ~l r :""1l 1

;~,

!II 1-· lt.:.!n:n •. \.0 ~umn. ,,....,,..,, Ill l.-;,i .... ,. ~-""· ~ \".>B. l'AJ... p !.H

r 'I D c;.,,.,._ O.J<f 'f'<'-,,.-... p, .u ?..~h !u:r......,..h. Ferr.a;..;, R.:f-.,r. rmr.1.it,..Cd-·•U·; <?. ;.,.;,)

f~I S .U:,;,~. <t Ji. -.ud l11ar ..u.! }of::1ll A ~

[T( \" \' Abr-=-n. :t .I. -. ... 1. ln,u. •u.J M<1~ A~, ,~NII 1

,·,1 0 ,1,,;.,._,.._,. Ji.. !'.ia:L w.ir .w.: ~bl>.,\ '.;11<1 ,:~:,.i.o:. I°'( G. °""'<. r,t .ll .. !llu.:l L111r . ..:..: ~kl!I. A ~l I :'HJI H!.

[ ;01 l'rcn r~ -Liter the .!l;l)l Ai'S ·~-,,~ "'1 :be: F utun: oll l':1nldo Ph~=,. Sn.,"':n,w. LU, J.ty 11, ;!JUI

1.:1 Vl... ,M...,~..,., ~ .. ! ~ -.o,b. £A<:r.;,-H,,. L,:,~. T.cl. pr"""1r.,d •• the lillh lorr:rn,111~ L"'°" i~r:,n;,: .,. C,t.inmc1r, .11 11,eh [n.:r~ Ph~..:1. ~ ~w.Jl !.l !'l, ::oo:

!l!I D A..u•u, e1 at. :-..id. I.am . .uiJ Mrth. A ~ !!'HI IS~ (I \I TESLA T«ho..:41 0,,.,.811 ke!"rt. C"f'.Jn Of~ ... , 1Ulll ... : '·

DE.SY. H=iur;. ~- !J.l,l. (!-'I M i\lbro ... cuL S.rl h11u . ...,,,t M.:l!l A. .....,,1tlll.!d!l. [:!] M Ur...,. "' .d .• :a~ibc.u.un ,,i ,i,., r.,"!.11a!i.:w

~15,:,i • ~ ,,.,..,c.. :-.u.:L llbll'. ;sDli \ldh. A .. ~"1 i~)JU.

[tt.f I\. W~aa. CJ= fib,n .-1 ,h: l'r,:,,p:as frx luau• C.wnmetl) ill the 1~. ~ Lt\~L Pr.x,,ei::,¥ ,:,f tt.:, Scn.,,..11 l1111:nw""""11 c .. ~.., a C.JJ.>cmct.-. .a lfi~ f..,,,~, Ph,..:s.. T -.;wn, IW'l, Wo>d.l S.lffll.lic. 'i.4~,-a. t'l'I:\. pp l!i1 l~I

Documents

Olga's thesis