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ttbar  τ + jets : Update on QCD Estimation

ttbar  τ + jets : Update on QCD Estimation. William Edson SUNY at Albany. New Event Selection Verification. Single Bin Tests for Variance. Using the first derivative: Calculated variance ( σ i ): 8.42421 Gaussian fit sigma: 8.48931 Webpage crosscheck*: 8.4

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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. New Event Selection Verification

  3. Single Bin Tests for Variance • Using the first derivative: • Calculated variance (σi): 8.42421 • Gaussian fit sigma: 8.48931 • Webpage crosscheck*: 8.4 • Results imply using first derivatives to determine σi to be consistent • Webpage: http://www.colby.edu/chemistry/PChem/scripts/error.html

  4. Current Results • Signal Fraction: 0.837897 ± 0.0775282 • chi2 minimum: 47.3013

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

  6. 2nd highest pTbjet reconstruction • Results for plot: • chi-square: 20.60 • p-value: 0.1501 • ndf: 15 • chi/ndf: 1.373

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

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

  9. Back-up

  10. 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

  11. 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

  12. σi by Operation Details

  13. σi by First Derivative

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

  15. 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

  16. 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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