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ttbar  τ + jets : Update on QCD Estimation

ttbar  τ + jets : Update on QCD Estimation. William Edson SUNY at Albany. Cutflow. C0: GRL C1: Trigger C2: Primary vertex with ntracks > 4 C3: Electron/ muon overlap, larVeto C4: Jet cleaning C5: Lepton Veto C6: tau n ≥ 1 C7: n jets >= 4 with eta < 2.5 and | jvf | > 0.75

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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. Cutflow • C0: GRL • C1: Trigger • C2: Primary vertex with ntracks > 4 • C3: Electron/muon overlap, larVeto • C4: Jet cleaning • C5: Lepton Veto • C6: tau n ≥ 1 • C7: njets >= 4 with eta < 2.5 and |jvf| > 0.75 • C8: MET > 60GeV • C9: MT < 80GeV • C10: >= 1 bjet • C11: Trigger matched tau n ≥ 1 and pT >= 40GeV • C12: MC tau object match

  3. 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

  4. Chi-squared minimization cont. • σi determined using factors for: • bin error: • data • signal, MC • QCD template • other backgrounds, MC • statistical error: • data: signal region • other backgrounds, MC • signal, MC • QCD template (uncertainty of background region data and all MC background region carried through via default SumW2

  5. New Event Selection Verification

  6. MT Plots

  7. Current Results • No jvf applied: • Signal Fraction: 0.837897 ± 0.0775282 • chi2 minimum: 47.3013 • Efficiency: 1.3809x10-3 • σ = 209.114 ± 19.349pb • Using jvf in object selection and jvf_sf: • Signal Fraction: 0.824826 ± 0.0763352 • chi2 minimum: 46.54513

  8. Gauss Fit to Ensemble Test • Mean: 0.781932 • Sigma: 0.073487

  9. Back-up

  10. New Event Selection Verification

  11. Systematic Values

  12. Highest pTbjet reconstruction • Results for plot: • chi-square: 8.389 • p-value: 0.8681 • ndf: 14 • chi/ndf: 0.5992

  13. 2nd highest pTbjet reconstruction • Results for plot: • chi-square: 20.60 • p-value: 0.1501 • ndf: 15 • chi/ndf: 1.373

  14. Dijet reconstruction • Results for plot: • chi-square: 4.581 • p-value: 0.9497 • ndf: 11 • chi/ndf: 0.4165

  15. Closest Top mass reconstruction • Results for plot: • chi-square: 6.075 • p-value: 0.8683 • ndf: 11 • chi/ndf: 0.5523

  16. σi by First Derivative

  17. Function Fits of QCD Templates Mean: 171.283 ± 5.986

  18. 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

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