Inclusive Lepton Production D

1
Inclusive Lepton Production _at_ DØ
Carsten Magaß
Thomas Stapelberg
III. Physics Institute A RWTH Aachen
(presented by Thomas Stapelberg)
DØ - Germany - Meeting December 4 - 5, 2003
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Objective
simulate and measure the inclusive production
XS differential in transverse momentum integrated
over observed pseudorapidity range
inclusive ? count e/µ-candidate with highest
energy
Goal Comparison of the measured lepton
production at hadron colliders with the standard
model prediction
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Outline

• Pythia simulations
• Datasets and Selection
• Efficiencies
• Background
• Results
• extra on W and Z
• (done by Carsten)

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Pythia-Generator-Simulation for Muons
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Datasets for Muon Analysis

• data taking period August 2002 February
  2003
• data TMB (p13.06.01)
• - analysis low pt unskimmed data
• - analysis high pt top skim mutrack
• - trigger efficiency top skim muTrig
• - central matching efficiency top skim
  dimu
• TMB -gt .root tuple with TopAnalyze package

Llow 0.115 pb-1
Lhigh 15 pb-1
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Muon Selection

• triggered event (MU_W_L2M5_TRK10,
  MU_W_L2M0_TRK3)
• medium muon with local track in
• bottom quadrant is excluded
• track matched with ncft and nsmt ,
• track dca cm, track z0 cm
• momentum consistency cut

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Muon Trigger Efficiency
Idea get unbiased sample with muons in
it Unbiased sample events triggered by
jet/em-triggers
events moun trigger has fired and muon found
eTrig
events muon found
L1 efficiency
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Cosmic Muon Background
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Inclusive Muon Production
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Pythia-Generator-Simulations for Electrons
this analysis
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Datasets for Electron Analysis

• data taking period September 2002 January
  2003
• skimmed TMB (p13.05.00)
• - analysis new phenomena skims 1em
• - trigger efficiency top skims emTrig
• - reco efficiencies top skims etrack
• - background studies wz skims
  wzskim_emjet
• TMB -gt .root tuple with TopAnalyze package

Lint 40 pb-1
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Electron Selection

• use EM_HI triggers
• gt 90 fraction of EM energy deposited in EM
  layer of the calorimeter
• isolation iso lt 0.15
• H Matrix HM lt 20
• fiducial requirement
• additional matched track

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EMID and Trackmatching Efficiency
(use tag and probe method)
Method use electrons from Z decay
tight electron
Tracker
Z
EM calorimeter
?
test cuts emf, iso, HM
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Background
photons from p0 decay ? real electrons ?
EMID matched track
need to know the probability of objects (QCD jets
or other) passing the EMID ( faking an
electron) and having a track match ( fakerate
fQCD ) ?
look at events with 2 jets
Signal/Background 0.085
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Inclusive Electron Production
Pythia Generator full detector simulation
Generator (PYTHIA)
Lumi
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Combined Plot of the two Analyses
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Z Production Cross Section
Event selection 2 isolated electron candidates
(subsample of incl. electron sample)
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W and Z Production
DØ
Th.
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Conclusion

• Pythia simulations
• efficiencies and acceptances (calculated mainly
  from data)
• background
• inclusive electron and muon production
• no indication of physics beyond the SM
• W and Z production cross section
• indirect measurement of W width

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Backup Indirect measurement of W Width
Input
SM
NNLO calculation
LEP