ttbar  τ + jets : Update on QCD Estimation

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ttbar  τ + jets : Update on QCD Estimation. William Edson SUNY at Albany. Chi-squared minimization. Equation: N(x): total number of events of type x for distribution n(x) i : number of events in bin of type x frac (Sig): fraction of N(Remain) expected to be Signal

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## ttbar  τ + jets : Update on QCD Estimation

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### ttbarτ + jets:Update on QCD Estimation

William Edson

SUNY at Albany

Chi-squared minimization
• Equation:
• N(x): total number of events of type x for distribution
• n(x)i: number of events in bin of type x
• frac(Sig): fraction of N(Remain) expected to be Signal
• binfrac(x)i: fraction of events in bin of type x expected from MC or template
• σi: uncertainty in bin i
Chi-squared minimization cont.
• bin error:
• data
• signal, MC
• QCD template
• other backgrounds, MC
• statistical error:
• data: signal region (times 2)
• data: background region
• other backgrounds, MC (times 2)
• signal, MC
• signal and other backgrounds combined, MC: background region
Results
• Chi-square: 3.747
• signal fraction: 0.91933 +/- 0.157592
• signal fraction for all data: 0.819601
Ensemble tests with result signal fraction

Results with Gaussian Fit

Associated Errors

Mean: 0.764889 +/- 0.002659 Sigma: 0.0805555 +/- 0.0020661

Linear Fit with Signal Fraction from 0.1 - 0.8

y(0): -0.00998677 +/- 0.05173513

slope: 0.912698 +/- 0.1009633

Proceeding Acceptance and Efficiency Work
• Efficiency: Limiting to events in 105200 sample satisfying:
• contain truth matched taus
• single prong
• muonVeto and eleBDTMedium == 0
• calo-seeded taus
• Acceptance: Using all MC types
• Nrec: MC events passing entire cutflow
• Ngen: 105200 events using mc and trueTau branch information matched to single prong, BDTJetScore > 0.7 taus
Highest pTbjet reconstruction
• Results for plot:
• chi-square: 7.341
• p-value: 0.7709
• ndf: 11
• chi/ndf: 0.6674
2nd highest pTbjet reconstruction
• Results for plot:
• chi-square: 13.76
• p-value: 0.3166
• ndf: 12
• chi/ndf: 1.147
Dijet reconstruction
• Results for plot:
• chi-square: 6.133
• p-value: 0.8643
• ndf: 11
• chi/ndf: 0.5575
Closest Top mass reconstruction
• Results for plot:
• chi-square: 5.342
• p-value: 0.8035
• ndf: 9
• chi/ndf: 0.5936
Cutflow
• C0: GRL
• C1: Trigger
• C2: Primary vertex with ntracks > 4
• C3: Electron/muon overlap, larVeto
• C4: Jet cleaning
• C5: Lepton Veto
• C6: njets >= 4 with eta < 2.5 and |jvf| > 0.75
• C7: MET > 60GeV
• C8: MT < 70GeV
• C9: Sum ET < 500GeV
• C10: >= 1 bjet
• C11: Tau n ≥ 1, BDTScore > 0.7
• C12: Trigger matched tau n ≥ 1 and pT >= 40GeV
• C13: MC tau object match