dijet analyses for icd resolution and response

Dijet Analyses for ICD Dijet Analyses for ICD Resolution and ResponseResolution and Response

Barry SpurlockBarry Spurlock

The University of Texas at ArlingtonThe University of Texas at Arlington

April 8, 2004April 8, 2004

April 8, 2004 Barry Spurlock 2

OUTLINEOUTLINE• Motivation

• DPCC and How We Used It

• Data

• Analyses & Results

• Conclusions


MotivationMotivation• Dijet study of QCD background (P13)• ICD-MG Task Force (ICD weighting factor)• Initial analyses performed

• 150k JT95TT events

• More data• fixed & corrected• Needed more processing power

• DPCC


DPCCDPCCDistributed & Parallel Computing ClusterDistributed & Parallel Computing Cluster

• Joint effort including UTA CSE dept., UTA HEP dept., and UT Southwest Medical Center (Dallas)

• 97 machines/193 processors• Pentium 4 Xeons at 2.4-2.6 GHz• Over 72 terabytes disk space• The DPCC is supported, in part, by the

NSF grant EIA-0216500


General ProceedureGeneral Proceedure• “Submit_to_PBS”

• Assign job names • Submits “run_in_batch”

• “run_in_batch”• Copy data files, root macro, & tarfile

• File list & root macro are chosen using the job name

• Tarfile includes C++ program, header, MakeClasses

• Runs the root macro as a ROOT batch job

• Root macro makes classes, chains the data files, assigns values to global variables, & runs code

• Compilation problems


Data & Data ProcessingData & Data Processing• Started with thumbnails from QCD group skim of P13

jet data• 200GB, 1281 files, 9.7M events

• tmbfixer & d0correct– Used d0tools to run– Took time to find right version of tmbfixer– d0correct compiled locally

• Skimmed out JT45TT, JT65TT & JT95TT• Skimmed out events with exactly two ‘good’ JCCB

jets, back-to-back (±10°)• 0.5<emf<.95, chf<0.4, hot<10.0, n90>1.0• Events: 170k JT45TT, 160k JT65TT, 37k JT95TT


AnalysesAnalyses

• ICD resolution versus ICD weighting factor

• Dijet asymmetry and response by eta for various ICD weighting factors

• Least squares best fit


ICD ResolutionICD Resolution

• CC-ICD and CC-MG events used

• Cut on narrow ET band of CC jet

• Sigma/E½ used as the resolution of probe

• Resolution plotted against ICD factor for 6 ET bins (60, 75, 85, 100, 120, 150)

Resolution vs. ICD Weighting FactorCC-ICD Events at 120 GeV from JT95TT Data

2.22

2.24

2.26

2.28

2.3

2.32

2.34

2.36

2.38

2.4

2.42

0 1 2 3 4 5 6

ICD Weighting Factor

Res

olu

tio

n

Max Control Eta 0.8 (2500 ev)

Max Control Eta 0.5 (1700 ev)

Parabolic Fit (Eta 0.8) Min at 3.04

Parabolic Fit (Eta 0.5) Min at 3.06


Dijet Asymmetry & ResponseDijet Asymmetry & Response

• CC “control” jet in narrow ET range• Other jet used as probe• Plotted asymmetry and response by eta bin• Plots made for 6 ET bands (60, 75, 85, 100,

120, 150) and various values of ICD weighting factor • 1.0, 1.5, 2.0, 2.4, 2.8, 3.0, 3.2, 3.4, 3.6, 3.8, 4.0,

4.2, 4.4, & 5.0


JT65TT/100 GeV/Factor 1.0JT65TT/100 GeV/Factor 1.0


Best Fit (Least Squares)Best Fit (Least Squares)• ET from probe jet is broken into parts

ETicd = icdf *ET ETccmg = ccmg*ET

ETch = chf*ET ETecmg = ecmg*ET

ETrem = ET – ETicd - ETccmg - ETecmg – Etch

• A linear combination of these is set equal to the ET of the control jet.

• A least squares fit is used to calculate the values of the factors for each part

• This was performed over a variety of eta ranges and ET bands.

• This was also performed where some of the coefficients were fixed to 1


Example of Least Squares FitExample of Least Squares Fit


Results/ConclusionsResults/Conclusions

• Submitting 133 jobs at 3 hours each and having it done the next day is very nice!

• …But getting all the results in such a short time is a bit overwhelming.

• The results will be discussed at the ICD-MG task force meeting tomorrow

• At a quick glance, 3.8 seems about right.

dijet analyses for icd resolution and response

Documents

icd factor

evparabolic fit eta

max control eta

eta binplots

tarfilefile list root

root batch jobroot macro

narrow et rangeother

events usedcut