Data Driven Decomposition Method for MET acceptance
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DONG LIU, ZHIJUN LIANG JULY 25, 2011 Data Driven Decomposition Method for MET acceptance 1
description
Data Driven Decomposition Method for MET acceptance. Dong Liu, Zhijun Liang July 25, 2011. Motivation. Bunch pile-up MET. Data Zee. The Idea --from Stefan etc. Use a data driven method to calculate MET acceptance for W/ Wgamma analysis MET = Real + Fake - PowerPoint PPT Presentation
Transcript of Data Driven Decomposition Method for MET acceptance
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DONG LIU, ZHIJUN LIANGJULY 25, 2011
Data Driven Decomposition Method for MET acceptance
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Motivation
Data Zee
Bunch pile-up MET
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The Idea --from Stefan etc.
Use a data driven method to calculate MET acceptance for W/Wgamma analysis
MET = Real + FakeFake MET extracted from the Z Events using
Decomposition method. Characterized by the boson pt and the event SumEt: Perpendicular to boson Pt
--random source ->SumEt Parallel to boson Pt
--Hadron energy scale ->Boson pt --random source ->SumEt
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Fake MET In Z events
Parallel MET Perpendicular MET
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Bias vs Z_pt
Perpendicular MET
Parallel MET
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MET Resolution vs SumET
SumET: leptons/photons subtracted
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Bunch dependence
Zee events:
Data Data
MC MC
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Bunch dependence
Data Zee events:
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Bias from W/Wgamma
Wenu Wgamma
Wgamma FSR Wgamma ISR
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MET calculation
Parallel MET
Perpendicular MET
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Fake MET
Zee WenuRed :MET_Truth-MET_recoBlack:Smearing function in previous page
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MET
Wenu Wgamma
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Acceptance
AcceptanceUncertainty(stat.)
Non_Closure
Wgamma
Truth MET 69.08% 0.09%Reco MET 71.05% 0.08%MC Smearing 70.94% 0.08% -0.15%Data Smearing 70.96% 0.07% -0.12%
AcceptanceUncertainty(stat.) Non_Closure
Wenu
Truth MET 70.27% 0.06%Reco MET 70.86% 0.06%MC Smearing 71.35% 0.07% 0.68%Data Smearing 71.31% 0.07% 0.63%
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Systematic Uncertainties
Calculation: statistical uncertainties ->plenty
events Difference between in Z and W(gamma) events Background in Z events ->small
Incorrectly determined SumEt Difference between Reconstruction MET and
new MET -- Non_Closure test
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Sumet
Wenu Wgamma
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Sumet +-10%
Wenu Wgamma
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Uncertainty due to sumet
Sumet were shifted by 10%
Acceptance Uncertainty
Wgammasumet -10% MC Smearing 70.79% -0.22%
Data Smearing 70.76% -0.28%
sumet +10% MC Smearing 71.09% 0.21%Data Smearing 71.07% 0.16%
Acceptance Uncertainty
Wenusumet -10% MC Smearing 71.20% -0.20%
Data Smearing 71.18% -0.17%
sumet +10% MC Smearing 71.47% 0.17%Data Smearing 71.44% 0.18%
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Conclusion
Could calculate the MET acceptance using Data Driven Decomposition Method
Uncertainties
Wenu WgammaNon_Closure 0.7% 0.2%Sumet shift 0.2% 0.3%Difference Between Z/W(Wgamma)? ?
other source ? ?
