NC 98/99 Analysis

C. M. Cormack (RAL)

Jason Breitweg, Ricardo Goncalo, Alexander Kappes, Amaya Lopez Duran-Viani, Matthias Moritz, Henning

Schnurbusch.

SFEW MEETING 5/6/2001

Diffractive Method - Results

Jets Method - Results

Summary

Hadronic Energy Response Study

Hadronic Energy Scale Uncertainty

• Double Angle Method Sensitive to Angular Variations in the Energy Scale

• Need to Calibrate each individual Calorimeter

• Also Possible to calibrate the HAC and EMC

The 2 Methods Used

• Diffractive Method

Allows the Direct Isolation of Hadronic Energy in Each Calorimeter Section.

• Jets Method

Isolated Jets can be restricted to the BCAL

Large range in PT can be Covered

Calibrating the 2 Other Calorimeters not so simple

C. M. Cormack (RAL) NC98 xF3 Analysis 5/6/2001

Typical properties of Standard DIS events

• Event not well contained in central detectors

• Large Energy loss in beam pipe

• Strong dependence on beam pipe/FPC leakage

• Almost Impossible to have complete hadronic containment in F/B/RCAL

Look at PT Balance PTH/PT

DA PTH/PT

e

Hadronic PTH is dependant on the activity in the

whole detector Not possible to calibrate

Individual sections of the calorimeter without larger systematic uncertainties

C. M. Cormack (RAL) NC98 xF3 Analysis 5/6/2001

Energy Scales Checks From Standard DIS

Method•Standard DIS events with max < 3.4

• yJB > 0.01 - To ensure sufficient hadronic activity

• MX > 2 GeV - To ensure sufficient hadronic activity

Look at PT Balance PTH/PT

DA

• Check individual calorimeters zMIN , zMAX

• Study the energy response PTH/PT

DA vs hadron

zMINzMA

X

eDADAT EP sin

The Solution: Use Diffractive (LRG) Events C. M. Cormack

PTH = Hadronic PT from cells

C. M. Cormack (RAL) NC98 xF3 Analysis 5/6/2001

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Isol

ated

Diff

ract

ive

Eve

nts U

sed

in S

tudy

FCA

LR

CA

L

BC

AL

Sele

ctio

n

max

< 3

.4

yJB

> 0

.01

MX >

2 G

eV

CA

L IS

OLA

TIO

N

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Energy Scales For DIS

• At present there are no tunings of the hadronic energy scales only factors as applied in RCALCOR

A Priori Scale Factors (DATA):

FCAL = 1.00

BCAL = 1.05

RCAL = 1.022

• 98/99/00 Dead material map

• Double angle PT From CorandCut unbiased

NOTEThe scale factors determined from this analysis should be applied to versions of the MC num98t3.1 and above

ONLY!

C. M. Cormack (RAL) NC98 xF3 Analysis 5/6/2001

• Within the Acceptance PT_DA Method unbiased

• Cross Checked Possible with Electron PT

Acceptance reduction due to max cut

Acceptance reduction due to Q2 cut

Angular acceptance cuts: 0.05< < 2.75

Diffractive Energy Scales - PT Method

C. M. Cormack (RAL) NC98 xF3 Analysis 5/6/2001

HADRON

Plot of PTDA / PT

TRUE

Determination of Hadronic Energy Scales

C. M. Cormack (RAL) NC98 xF3 Analysis 5/6/2001

AFTER ISOLATION CUTS

BCAL

RCAL

FCAL

DATAMC

P THA

D/P

TDA

MC DATAFCAL 0.866 0.86BCAL 0.85 0.825RCAL 0.8 0.8

Energy Scale factors Determined

Statistical Error

0.5 % F/B CAL

2% RCAL

Diffractive: Determination of HAC/EMC Scales

• FCAL: No Need to Tune Factors -Values within Errors (1%)

• BCAL: EMC (MC) scaled down 2% 98% (+/- 1.5 %)

BCAL: HAC (MC) scaled down 4% 96 % (+/- 1 %)

• RCAL: Scale factors Unchanged (+/- 2% (stat))

How does the Hadronic Plot look after ?

• Energy Scales Look Very Good for whole Angular Range

• Front End of BCAL is off for HADRON < 1. Next slide….

• Possibility (need!) to Tune 1st Inner Ring of FCAL ?

AFTER ISOLATION CUTS

C. M. Cormack (RAL) NC98 xF3 Analysis 1/3/2001

FCAL

BCAL

RCAL

P TH/P

TDA

HADRON

Ene

rgy

Scal

e D

eter

min

atio

n Fr

om J

ets

Jet E

vent

Sel

ectio

n

• Sta

ndar

d N

C D

IS E

vent

Se

lect

ion

• Jet

s Sel

ecte

d us

ing

Con

e A

lgor

ithm

- In

BC

AL

1c <

Jet

< 2.

2 c

||

Jet -

e |

- 1

80|

< 40

Forw

ard

Ener

gy F

low

R

estic

ted

FC

AL

Ener

gy O

utsi

de 2

In

ner R

ings

< 2

0 G

eV

1.1/9.0 HADT

JetT PP

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BCAL Energy Scale Determination From Jets

Total Scale

Overall Total Hadronic Response off by 2-3%

EMC/HAC fractions

MC

DATA

FIT EMC/HAC Fractions

• HAC 95% +/- 1.0%

• EMC 98% +/- 1.5%

BCALEnergy Scale Determination From Jets

Linearity - Energy Response vs. PT

DATA

MC

Overall Energy Scale is Off by 2-3% for the whole PT Range

Consistent with the Number From Diffractive Method

Sum

mar

y an

d C

oncl

usio

n of

Ene

rgy

Scal

e Sy

stem

atic

• Rel

ativ

e H

adro

nic

Ener

gy re

spon

se h

as b

een

dete

rmin

ed

for F

/B/R

CA

L

• Res

ults

from

the

Diff

ract

ive

Met

hod

are

in g

ood

agre

emen

t with

in e

rror

s w

ith th

ose

from

Jets

Met

hod

• Res

ults

for H

AC

/EM

C fo

r F/B

CA

L

• Err

or c

heck

s und

erw

ay -

resu

lts st

able

to 0

.5%

BC

AL

FIT

EM

C/H

AC

Fra

ctio

ns

• H

AC

9

5% +

/- 1.

0%

• EM

C

98%

+/-

1.5%

FCA

LFI

T E

MC

/HA

C F

ract

ions

• H

AC

1

00%

+/

- 1.0

%

• EM

C

100

%

+/- 1

.5%

RC

AL

FIT

EM

C/H

AC

Fra

ctio

ns

• H

AC

1

00%

+/-

2.0%

• EM

C

100%

+/-

2.0%

Sum

mar

y of

Sca

le fa

ctor

s (M

C)

Energy Scale Determination From Jets

Systematic Checks

• FCAL Energy < 5 GeV (0.5%)

• Jet PT Linearity Response (0.5%)

• Different Jet Algorithm ! (0.5%)

• MEPS / ARIADNE - Understudy

Look for Sample of Events with a Jet in RCAL

with little E-FLOW in the rest of the Detector