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ttbar  τ + jets : Update on QCD Estimation

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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  1. ttbarτ + jets:Update on QCD Estimation William Edson SUNY at Albany

  2. 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

  3. Chi-squared minimization cont. • σi determined by adding in quadrature • 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

  4. Results • Chi-square: 3.747 • signal fraction: 0.91933 +/- 0.157592 • signal fraction for all data: 0.819601

  5. Ensemble tests with result signal fraction Results with Gaussian Fit Associated Errors Mean: 0.764889 +/- 0.002659 Sigma: 0.0805555 +/- 0.0020661

  6. Linear Fit with Signal Fraction from 0.1 - 0.8 y(0): -0.00998677 +/- 0.05173513 slope: 0.912698 +/- 0.1009633

  7. Back-up

  8. 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

  9. Highest pTbjet reconstruction • Results for plot: • chi-square: 7.341 • p-value: 0.7709 • ndf: 11 • chi/ndf: 0.6674

  10. 2nd highest pTbjet reconstruction • Results for plot: • chi-square: 13.76 • p-value: 0.3166 • ndf: 12 • chi/ndf: 1.147

  11. Dijet reconstruction • Results for plot: • chi-square: 6.133 • p-value: 0.8643 • ndf: 11 • chi/ndf: 0.5575

  12. Closest Top mass reconstruction • Results for plot: • chi-square: 5.342 • p-value: 0.8035 • ndf: 9 • chi/ndf: 0.5936

  13. 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

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