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Conversano(Ba) 17/106/03 QCD@Work2003 Marcello A. Giorgi 1 BABAR Status and Future Plans Marcello A. Giorgi on behalf of BaBar Collaboration QCD@Work2003 Conversano (Ba)- Italy

BABAR Status and Future Plans

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BABAR Status and Future Plans. Marcello A. Giorgi on behalf of BaBar Collaboration QCD@Work2003 Conversano (Ba)-Italy. BaBar Physics GOALS. 1)Search for CP violation in B meson decays largely predicted by the Standard Model - PowerPoint PPT Presentation

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Page 1: BABAR Status  and Future Plans

Conversano(Ba) 17/106/03 QCD@Work2003

Marcello A. Giorgi 1

BABAR Status and Future

Plans

BABAR Status and Future

Plans Marcello A. Giorgi

on behalf of BaBar Collaboration

QCD@Work2003

Conversano (Ba)-Italy

Page 2: BABAR Status  and Future Plans

Conversano(Ba) 17/106/03 QCD@Work2003

Marcello A. Giorgi 2

1)Search for CP violation in B meson decays largely predicted by the Standard Model

2)Test extensively at this low energy scale the Standard Model by measuring precisely enough quantities to impose constraints on the Standard Model parameters

CP in b sector has been established by BaBar and Belle (2001)

TRY to open windows on new Physics beyond Standard Model

More precise CKM measurements, Rare B decays, Charm study, Tau rare decays .

BaBar Physics GOALS

Page 3: BABAR Status  and Future Plans

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Marcello A. Giorgi 3

CP in Standard Model

CKM quark mixing matrix

2

2 4

3

23

2

( )

(

11

21

1 ( )2

11 )

ud us ub

cd cs cb

td ts tb

A iV V V

V V V V A O

V V VAA i

bulB() l

CP Violating phase

BD(*)lbcl

B() B0 Mixing

Unitarity

Page 4: BABAR Status  and Future Plans

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Marcello A. Giorgi 4

O(2)

Representing unitarity relations as

Unitarity Triangles The unitarity condition of CKM matrix VV+=V+V=1 gives 6 relations between the matrix elements as :

VudV*ub + VcdV*cb + VtdV*tb =0

(in this relation the 3 terms have the

same order of magnitude ~O(3) and it can be graphically represented in a complex plane as a triangle with sides of comparable length. Other relations have terms of different order of magnitudes. E.g.:

VusV*ub + VcsV*cb + VtsV*tb =0

O(4) O(2)

Overconstrain and the 4 parameters of CKM , A

Page 5: BABAR Status  and Future Plans

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Marcello A. Giorgi 5

Decaying amplitudes in SM

Tree

Penguin

Quarks Leading Term Secondary SampleBd Angle ccs Vcb Vcs* =A2 VubVus*=A4(i) J/ Ks

T+P(c-t) P(u-t)

sss VcbVcs*= A2 VubVus*=A4(-i) Ks P(c-t) P(u-t)

ccd Vcb Vcd* =A2 Vtb Vtd* =-A3 (1-+iD+D- (LT) T+P(c-u) P(t-u) uud/ddd VubVud*=A3(i) Vtb Vtd* =-A3 (1-+ia(LT)

T+P( u-c) P(t-c)

Page 6: BABAR Status  and Future Plans

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Marcello A. Giorgi 6

Experimental ingredients: BaBar optimized for time dependent CP

asymmetries

+e-e

z

Brec

Btag 4s

(4S) = 0.55

Coherent BB pair

B0

B0

Start the Clock

zc

zt

1

Tag vertex reconstructio

n

Tag vertex reconstructio

n

FlavorTaggingFlavor

Tagging

Exclusive B Meson and Vertex Reconstruction

Exclusive B Meson and Vertex Reconstruction

0sK

J/

Page 7: BABAR Status  and Future Plans

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Marcello A. Giorgi 7

PEP-II Asymmetric B-Factory

(4 )e e S BB B B production threshold

9 GeV e- on 3.1 GeV e+

(4s) boost in lab frame

= 0.55

Page 8: BABAR Status  and Future Plans

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Marcello A. Giorgi 8

BABAR

DCH

EMC

DIRC

COIL

IFR

SVT

The The BBAABBARAR CollaborationCollaboration 10 Countries 75 Institutions 579 Physicists

Page 9: BABAR Status  and Future Plans

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Marcello A. Giorgi 9

Silicon Vertex Tracker• dE/dx measurement for PID.• Measure the track parameters just outside the beam pipe.• 5 layers of double sided silicon stripsSingle hit resolutions in the inner

layers d0 55 m, z0 65 mSoft from the D* D s decays extends below pT< 150 MeV/c

Page 10: BABAR Status  and Future Plans

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Marcello A. Giorgi 10

Detector of Internally Reflected Cherenkov light

K/ discrimination

144 fused silica bars (1.7 cm thick) Cherenkov light transported by internal reflection

11000 PMTs,

25-50 p.e./particle

10 mrad single

photon resolution

Page 11: BABAR Status  and Future Plans

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Marcello A. Giorgi 11

ElectroMagnetic Calorimeter

6580 CsI(TI) crystals Barrel 48 rings in , 120 crystals per ring Forward Endcap 8 rings in , 80/100/120 crystals per ring Angular coverage: 126o in , 360o in reconstructed from mass width varying from 5 to 9 MeV/c2 for 0.2<EGeV

Electron i.d. efficiency up to 90% misidentification probability at the level of

1 10-3.

Page 12: BABAR Status  and Future Plans

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Marcello A. Giorgi 12

Instrumented Flux Return

Number of active elements342 barrel RPC432 endcap RPC32 cylindrical inner RPC

Total surface covered2000 m2

Gas mixtureArgon 60.5%Freon 35%Isobutane 4.5%

Electronics50000 channels

Muon identification efficiency for tight criteria 65% for a misidentification at the level of 2%

Neutral hadrons (namely KL) are detected after their

interaction with iron.Only direction is measured

Page 13: BABAR Status  and Future Plans

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Marcello A. Giorgi 13

Time dependent rate,flavor mixing and CP,T,CPT

Time dependent rate:dN exp(–|t|/B) ( 1 ± D (S sin(mt) - Ccos(mt)) ) R

2

2

21

1

1

Im2

CS

CPV in Mixing -DecayCPV direct

cp

cp

cp A

A

p

q___

D is the mis-tag dilution

R is the time resolution

0B

0B

CPfCP

mix

ing decay

CPfA

CPfA

t

2

22

im

iMz

z0 CP & CPT violation

1p

q CP and T Violation in mixing

42

2

105sin41 t

c

m

m

p

qSM

Page 14: BABAR Status  and Future Plans

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Marcello A. Giorgi 15

Sin2 and decay

s

Page 15: BABAR Status  and Future Plans

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Marcello A. Giorgi 16

Time dependent analysis B

*Assume no direct CPV

* From control sample B

Expect zero!

In SM Ss=sin 2

Page 16: BABAR Status  and Future Plans

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Marcello A. Giorgi 17

LOOK for N.P. in Loops?

from charmonium channelsResults are so far CKM

compatible but…

s

s

s

d

KS

s

s

s

dsin(2) = 0.741 ± 0.067stat ± 0.033syst

?

Page 17: BABAR Status  and Future Plans

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Marcello A. Giorgi 18

B0 +- sin2eff

With incomplete information on Penguin contamination:• Measure S and Cfrom

both sinmt and cosmt terms .

• Compare with predicted S and Cvalues for given , , |P/T|, and . Assume for instance:

From sin2eff to sin2?

isospin analysis, needs B0

22

3021

28.0/

26

)97(

TP

cf. Gronau and Rosner, Phys. Rev. D65, 093012 (2002)

BABAR

Belle 1

Belle 2

Page 18: BABAR Status  and Future Plans

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Marcello A. Giorgi 19

B0 ) the CP fit• Time integrated direct CP:

• Time dependent CP:

• Asymmetry between rates:

08.017.028.0 KCPA

03.008.018.0 CPA

04.018.036.0 C

03.024.019.0 S

03.00.250.15 S

04.00.28 0.180.19-

C

First step towards in B. Full Dalitz analysis in progress.

Preliminary

Page 19: BABAR Status  and Future Plans

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Marcello A. Giorgi 20

Toward : the BD0CP K approach

sin2 from the triangles (Gronau-Wyler method):

BaBar measurements:

2

DD

:seigenstate CP are Dwhere00

CP

0CP

D

)(2 0 KDBA CP

)(2 0 KDBA CP

)%20.035.031.8()(

)(0

0

DBBF

KDBBFR

)%5.06.18.8()()(

)()(00

00

CPCP

CPCP

CP DBBFDBBF

KDBBFKDBBFR

06.017.006.0)()(

)()(00

00

KDBBFKDBBF

KDBBFKDBBFA

CPCP

CPCP

CP

Preliminary

Page 20: BABAR Status  and Future Plans

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Marcello A. Giorgi 21

|Vub| from fully tagged SL decays

Brecoil

BrecoD(*)

Y(4S) l

Xu

Recoil of fully reconstruted B (~4KB /fb-1)

bul signal:MX (< MD)( ~ 60-80%)

S/B 1.7: good!

Preliminary

Page 21: BABAR Status  and Future Plans

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Marcello A. Giorgi 22

Rare B decays

b u : tree, CKM suppressed

b s,d: Radiative (QCD, EM, EW) Penguins FCNC

Leptonic decays: B0 l+l-, B , B l+, …

tree

QCDpenguin

EMpenguin

EWpenguin

probes b inside B

Possible New Physicssignatures: rates and phasesfrom virtual particlesin the loops

Page 22: BABAR Status  and Future Plans

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Marcello A. Giorgi 23

Not only B Physics in BABAR !

A new state at m=2317 MeV decaying into D+

s(1970) and 0 has been discovered by us and recently confirmed by CLEO and BELLE !

D+s 0

D+sK+K- + D+

sK+K- + 0

Page 23: BABAR Status  and Future Plans

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Marcello A. Giorgi 24

An example: D mixingVery small in the S.M. 2 additional suppression

A window for new physics

Charm, tau discovery potential

limit3

005.0 222

SU

mmm Wds

lepton number is violated inmany extensions of the S.M.(present limits, O(10-6) are not far from some model predictions)

D0

c

c

u

ud,s d,s

W-

W+

Vcd,cs

V*cd,csV*

ud,us

Vud,us

D0

“long distance” -iy

“short distance” x

D0 D0

K-,

K+,+

Another example: lepton flavour violation

S.M., extended to include mixing and mass:

BR( O(10 - 34)

Page 24: BABAR Status  and Future Plans

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Marcello A. Giorgi 25

An Example: D0 Mixing

• y parameter from ratios of D0 K, KK, lifetimes:Comparison with previous

Measurements:

Page 25: BABAR Status  and Future Plans

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Marcello A. Giorgi 26

• Wrong sign (WS) decays D0! K+- can occur directly DCS or through mixing followed by the right sign (RS) CF decay:

• WS decays are not exponential:

… and D0 Mixing from Wrong Sign Decays

MixingDCS Interference

CFMixing

DCS

units of 0

Preliminary

Page 26: BABAR Status  and Future Plans

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Marcello A. Giorgi 27

Luminosity: Present and Future with PEPII “adiabatic scenario”

FY2002

FY2003

Longerterm

So far in Run 3: On peak 30.02 fb-1

Off peak 2.57 fb-1

Present peak 6.5 10 33 L/day=370 pb-1

Before end of the decade: 12 ab-1

Summer 2002 and Winter 2003:Run 1 + Run 2On peak 83.9 fb-1

Off peak 9.6 fb-1

92 M BB pairs

Summer 2003:Run 3add 40 fb-1

By 2006: 500 fb-1

Page 27: BABAR Status  and Future Plans

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Marcello A. Giorgi 28

Path to higher PEP-II luminosity

Luminosity 4.6E331E34 2E34 4E34 UnitsI+ 1800 2700 3600 4500 mAI- 950 1400 1760 2000 mABeta y* 11.5 9 7 4.5 mmBeta x* 50 50 50 50 cmBunch Length 1.3 1.0 0.8 0.5 cm# bunches 792 1300 1500 1600Vert. Emitt. 2.5 1.4 1.1 0.7 nmHoriz. Emittance 40/50 30/45 32/47 40/48 nm (+/-)Crossing angle 0 0 0 ~+/-8 mradTune shifts (x/y) 7.5/4.58.0/5.78.2/6.08.4/6.3x100Number RF stations 7 10 13 15Date hardware ready Jan 02 Dec 02Dec 04Nov 06Date for luminosity Jun 02 July 03 Dec 05Dec 07

(J.Seeman, BaBar Collaboration meeting, Sept.2002)

Page 28: BABAR Status  and Future Plans

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Marcello A. Giorgi 29

What about the BaBar Detector?BABAR is a VERY good detector: very difficult to improve it!!

No problem expected to the performance for L up to 4 1034 cm-2 s –1

Look at the innermost and outermost systems.

SVT IFR

Page 29: BABAR Status  and Future Plans

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Marcello A. Giorgi 30

SVTSVT is 98% efficient. No degradation due to irradiation has

been observed

SVT so far tested for rad hardness up to 4 Mrad (OK!) rad tests are going on.

Partial SVT replacement is considered by 2005. Almost 50% of total has been built and are on the shelf.

Instrumented Flux Return

Efficiency for muon and Klong detection has decreased since the beginning in 2002 the endcap has been upgraded using new RPC and thicker absorber

Page 30: BABAR Status  and Future Plans

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Marcello A. Giorgi 31

Absorber Segmentation

7 layers 2 cm

1 layer 7 cm

2 layers 9 cm

2 layers 13 cm

2 layers 10cm

total 85 cm

New Forward EndCap from nov 2002

Terminology: 19 slots and 15 RPC layers

RPC belt

Slot18/195 brass layers(slot 8,10,12,14,16)

Page 31: BABAR Status  and Future Plans

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Marcello A. Giorgi 32

IFR Barrel Upgrade

Muon selectors losing efficiency

Decision taken to increase the thickness of the absorber and to replace the bakelite RPC with a more robust detector (Limited StreamerTube).

INSTALLATION 2004 &2005

Many RPCs die since 1999. Fraction effectively dead is now almost 40%

Page 32: BABAR Status  and Future Plans

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Marcello A. Giorgi 33

Next about sin2• Extrapolated statistical and systematic uncertainties

Statistical uncertainty Golden modes

Param. Channel (stat)/(syst) 0.08 ab-1

(stat)/(syst) 0.5 ab-1

(stat)/(syst) 2.0 ab-1

sin2 Im(+) S S S

J/KS Golden D*D* J/0 KS ’ KS

0.08 / 0.03 0.07 / 0.03 0.43 / 0.13 0.49 / 0.16 0.50 / 0.09 0.34 / 0.03

0.037 / 0.018 0.031 / 0.018 0.16 / 0.07 0.20 / 0.20 / 0.14 /

0.018 / 0.018 0.015 / 0.018 0.08 / 0.03 0.10 / 0.10 / 0.07 /

21 L

1syststat ab2at L

(*)

(*) This syst error of 0.018 is dominated by DCS decays of charm in K tagged events. Lepton tag is not affected !

Page 33: BABAR Status  and Future Plans

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Marcello A. Giorgi 34

What next for Sin 2

Pure penguin process B Ks

The present value with 80 /fb is:

S=sin2=-0.19-0.50+0.52 stat.±0.09syst.

With 2/ab (S) goes down to 0.1

But also B ’ K and B K K K

NEW PHYSICS ?

New quanta in the loop?

Page 34: BABAR Status  and Future Plans

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Marcello A. Giorgi 35

Results (0.08 ab-1) for BFactories

Param. Channel (stat)/(syst) 0.08 ab-1

(stat)/(syst) 0.5 ab-1

(stat)/(syst) 2.0 ab-1

S C

+-

0.34 / 0.05 0.25 / 0.04

0.12 / 0.03 0.10 / 0.03

0.06 / 0.05 /

Extapolations for sin2eff

Extrapolated errors (BaBar)

Param. BaBar Belle S C

0.02 0.34 0.05 -0.30 0.25 0.04

-1.23 0.41 (+ 0.05-0.07) -0.77 0.27 0.08

Page 35: BABAR Status  and Future Plans

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Marcello A. Giorgi 36

r=0.2 (2ab-1), sin2fit: sin2

from B-D0(CP)K-: projections

Recent experimental results (BaBar)

Toy MC projections: (Fit unreliable for r = 0.1)

02.029.002.1)(

)(

0

11

KDB

KDBn

)02.026.072.0()(

)(

0

11

KDB

KDBp

r=0.3 (0.5 ab-1), sin2fitsin2

08.023.017.0 CPA

ACP=0.174 0.031

r=0.2 =60o =30o

(2ab-1)

KKD0500

)1.0(

)(

)(

0

0

O

KDBA

KDBAr

Page 36: BABAR Status  and Future Plans

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Marcello A. Giorgi 37

projected errors for |Vub|

Selection:One B reconstructed in D(*)XLepton momentum and neutrino massKaon veto, charge balanceFit Mx with constraints

MX distribution fit:

bul, bcl, backgroundErrors:

Statistical L(ab-1) = 0.08 0.5 2.0 10 stat(%) = 7.0 2.8 1.4 0.6

Experim. Systematic ~5% (now) 2.5% (bcl bkgd)

Theoretical ~ 9% ((mb)=90MeV) 5% (b ulabove cut)

Mx (GeV)

Page 37: BABAR Status  and Future Plans

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Marcello A. Giorgi 38

B beam method

“B – beam”

BrecoD(*)

Y(4S) l

h

B factories present an unique peculiarity. Events are pure B B and a full reconstruction of one side allow to treat the other as a pseudo B-beam. The study of rare decays with neutrinos are becoming possible with very high integrated luminosity.

Page 38: BABAR Status  and Future Plans

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Marcello A. Giorgi 39

Integrated luminosity vs physics

2sin

1 abLdt1.0 0.1 .105.0 0.2

BaBar2006 2009 ?

cbub VV 2sin2sin llKllX s

*, *, KX s

,

2002

Continuous improvement

Page 39: BABAR Status  and Future Plans

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Marcello A. Giorgi 40

Some comments about comparison with Hadron machine expts.

Lumi(10 33) bb(10-33) bb(107/year) bb /qq

Bfactories 10 1.1 11 3 10-1

BTeV 0.2 100000 20000 1 10-3

LHC-B 0.15 500000 75000 5 10-3

Page 40: BABAR Status  and Future Plans

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Marcello A. Giorgi 41

Some comments about comparison with Hadron machine expts.

CKM parameters BABAR/Belle BTeV/LHC-B 2 ab-1 107 s

Sin(charmonium) 0.015stat/0.018syst 0.025/0.014Sin (penguins bsss) 0.10 stat ----in S eff(B0 0.06 stat 0.024/0.056

eff – ( B0 ) <10° ----Sin() (B0 D* ) 0.15 ---- (B DK) 7° <10°/<19°|Vub| 1.4%+ Th. Unc.(now better 10%) ----

Of course Bs mixing and decay can be studied well at hadron machines ( and a lot of good physics from Bs)

Page 41: BABAR Status  and Future Plans

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Marcello A. Giorgi 42

Rare decays - SummaryChannel BF BTeV/LHC-B (107 s) BABAR/BELLE (2 ab-1)

bs 3.3±0.3 10-4 ---- 44.0K 6.8K(Btagged)

BK*10-5 25K 24.0KB ()10-6 ---- 1.2K

bs±1.5 10-6 3.6K 1.2Kbse+e- 1.4KBK*±1 10-6 2.2K/4.5K 0.5KBK*e+e- 0.6K

bs±0.9 10-5 ---- 30BK*10-6 ---- 6

B10-5 ---- 70B10-735

Limit< 10-8

Bfactory and hadron machine measurements are complementary !

Rates…Fully

reconstructed B on the other side are used

The so called

B beam option

Asymmetries!

Page 42: BABAR Status  and Future Plans

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Marcello A. Giorgi 43

SummaryBabar apparatus is generally very robust and can cope with

high luminosity environment above 10 34 (2004). Decision has been taken to upgrade the IFR Barrel with a different technology well established and robust (LST).

Preliminary measurements of pure penguin processes for sin2, measurements of Vub, B->DK, B->includingDalitz plot analysis.

FUTURE – In 2005 complete the installation of the IFR Barrel. Install the Spare modules of SVT, to replace the heavily irradiated modules on horizontal plane.

Approach the precision measurement with 0.5/ab of integrated luminosity .

Towards more than 1.0/ab (in a more aggressive scenario 4 10 34 after 2007) explore possible openings for new physics.Study of CP asymmetries but also rare decays in b, c and tau sectors.

Profit from full reconstruction of one B : “ Pseudo B beam”

Page 43: BABAR Status  and Future Plans

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Marcello A. Giorgi 44

BACKUP SLIDES

Page 44: BABAR Status  and Future Plans

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Marcello A. Giorgi 45

3-body (+-0) Dalitz analysis for

B0+ – - B00 0 Interference

Region

B0+ – - B0 – + Interference

Region

00

00

, ,

, ,

A A A

A A A

11 parameters (“fundamental”):

remove overall phase & normalization: 9 parameters

00, , , , ,T P T P T

Suffers from mirror solutions

No mirror solutions. Does not depend on particular weak phase decomposition

10 parameters (“amplitudes”):

remove overall phase & normalization: 8 parameters

obtain fundamental parameters from subsequent fit.

…work in progress

Page 45: BABAR Status  and Future Plans

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Marcello A. Giorgi 46

Flavour mixing and CP,T,CPT

m=mH-m L 2|M12| 0.5ps-

1

1/ 1.6 ps

=H-L |M12|Re (12/M12)

SM

1p

q CP and T Violation in mixing

42

2

105sin41 t

c

m

m

p

q

As in K sector where k=(p-q)/(p+q) ~O(10-3)

SM

Page 46: BABAR Status  and Future Plans

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Marcello A. Giorgi 47

Flavour mixing and CP,T,CPTCP an CPT conservation if H11=H22

2

22

im

iMz

2

2211 MMM

2

2211

t)),BB((Probt)),BB((Prob_

0_

000

0z

CP and CPT VIOLATION

Assumptions made in the usual sin2 analysis:0H L

12 122

12 122

1i

i

Mq

p M

11 22 11 222

2

( )0

i

i

M Mz

m

Page 47: BABAR Status  and Future Plans

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Marcello A. Giorgi 48

Search for B+ +

B candidate Semileptonic tagD0

Y(4S)

cosB,Dlfor B D0X tags

Total signal-side neutral energy

Semileptonic tags: BF(B+ +) < 4.910-4 (90% CL)Fully reco tags: BF(B+ + ) < 7.710-4 (90% CL)

combined: < 4.1 10-4

Preliminary

Page 48: BABAR Status  and Future Plans

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Marcello A. Giorgi 49

Upper bounds on = 2eff-2

0

0002

BF

BFsin

B

B

Grossman-Quinn bound: BaBar, present data:051

BaBar, extrapolations:vs BF(00), at fixed Luminosity

Small gainwith lumi

Most powerful at small BF

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Marcello A. Giorgi 50

0 2.5 5 7.5-2.5-5-7.5

0

10

20

30

-10

-20

-30

Meters

Ce

ntim

ete

rs

2x1034 Interaction Region with a ±3.25 mrad Xangle

M. Sullivan Jun. 14, 2000

QD1

QD4QF5

QF2

QD4 QF5

QD1 QD1

QD1

QF2

Extra focusing

Extra focusing

3.1 G

eV

3.1 G

eV

9 GeV

9 GeV

100 kW

100 kW

20 kW

20 kW

E36 B-Factory +/- 12 mrad xing angle Q2 septum at 2.5 m 8 GeV

30

20

10

0

-10

-20

-30

cm

-7.5 -5 -2.5 0 2.5 5m

Q1

Q1Q1

Q1

Q2

Q4Q5

Q2

Q4Q5

2 cm radius and 1 cm radius beam pipes

The 1 cm radius beam pipe intercepts about 5 kW of power from the LER and nearly the same amount from HER

Minimum amount of material in the detector beampipeThis conflicts with having enough SR shielding (usually a thin coating of Au) to keep detector occupancy at acceptable levelsMinimum radius for the beam pipe

This must be balanced with the requested thickness of the beam pipe. The smaller the beam pipe the more power it must be able to handle (kW).