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2010.02.08 StEemcGammaFilterMaker QA: QCD vs. gamma-jet ccept/reject rates

Updated on Tue, 2010-02-09 20:37. Originally created by seluzhen on 2010-02-08 12:48.

StEemcGammaFilterMaker QA

Pythia generated processes

Pythia gamma-jet Pythia QCD 2->2 processes
14 f + fbar -> g + gamma 11 f + f' -> f + f' (QCD)
18 f + fbar -> gamma + gamma 12 f + fbar -> f' + fbar'
29 f + g -> f + gamma 13 f + fbar -> g + g
114 g + g -> gamma + gamma 28 f + g -> f + g
115 g + g -> g + gamma 53 g + g -> f + fbar
  68 g + g -> g + g

Number of generated events per parton pt bin

  Number of generated events
(100events/job)
Parton pt range (GeV) 2-3 3-4 4-6 6-9 9-15 15-25
Pythia gamma-jet 50K 50K 50K 50K 50K 50K
Pythia QCD 2->2 processes 100K 100K 50K 50K 50K 50K

Filter configuration

Filter parameter Value Notes
mConeRadius 0.24  
mSeedThreshold 2.5 Cluster seed energy threshold
mClusterThreshold 3.7 Cluster Et threshold
mEtaLow 0.9 EEMC acceptance
mEtaHigh 2.1 EEMC acceptance
mSmearEnergy 0 Disabled
mThrowTracks 0 Disabled
mCalDepth 279.5 ZDC SMD depth
mMinPartEnergy 1e-05 Disabled by mThrowTracks=0
mHadronScale 0.4 Downscale factor for hadron energy
mFilterMode 0 Accepting all events

stasim/Pythia options

  • detp geometry y2006h
  • Calorimeter cut for electromagnetic processes: emc_10keV
  • call pytune(100): PYTUNE v1.015; CDF Tune A

Figures

Figure 1: Pythia Eemc gamma filter QA:
(left) False rejection, (right) fraction of accepted events

Comments

  • Overall false rejection is < 0.02% (10^-4)
    for both QCD and gamma-jet simulations.
  • In parton pt range 6-15 GeV the acceptance rate
    for the gamma-jet MC is ~ 50%
    (I think this is due to rapidity fiducial cut,
    otherwise it should be closer to 100%).
    For the QCD sample (in the same pt region)
    acceptance rate is 8-25%.
  • Somehow for highest parton pt filter acceptance is the
    same for gamma-jet and QCD Monte-Carlo.
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