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ttbar τ + jets : Update on QCD Estimation. William Edson SUNY at Albany. Intra-PDF Uncertainty Results. CT10: ± 2.32093 MSTW: + 1.29293 / - 1.38225 NNPDF: ± 1.20644. Envelope Results. Therefore the final uncertainty is equivalent to the CT10 Intra Unc : ± 2.32093.
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ttbarτ + jets:Update on QCD Estimation William Edson SUNY at Albany
Intra-PDF Uncertainty Results • CT10: • ± 2.32093 • MSTW: • + 1.29293 / - 1.38225 • NNPDF: • ± 1.20644
Envelope Results Therefore the final uncertainty is equivalent to the CT10 Intra Unc: ± 2.32093
Fit Selection Results • Final Result:
QCD Bin/Range Range increases/decreases in steps of 20GeV Bin amount increases/decreases in steps of 5
MC Generator 1.1)fullsim mc11c POWHEG+fPythia sample 117050 (SYST_Full_117050) and MC@NLO+fHerwig sample 105200 (MC@NLO(105200)) 1.2)fullsim mc11c POWHEG+fPythia sample 117050 (SYST_Full_117050) and the fullsim mc11c ALPGEN+HERWIG samples (AlpHerwig(baseline)) 1.3) AtlFast2 mc11b POWHEG+fPythia sample 117050 (SYST_AtF_117050) POWHEG+fHerwig sample 105860 (SYST_AtF_105860)
Y(0): -0.127757 ± 0.00142161 Slope: 1.18358 ± 0.00252649 Chi2: 34.4482 NDF: 8997 Linearity Testto All Values
MC Tau Plots MC Tau Children Count MC Tau Count MC Tau Children pdgID LeptonicpdgID values: e → 11, μ → 13, τ → 15
MT Signal vs Control vs MC Backgrounds Samples Normalized to Own Integrals Samples Normalized to Sum of Integrals
Cutflow • C0: GRL • C1: Trigger • C2: Primary vertex with ntracks > 4 • C3: Electron/muon overlap • 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
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. • 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
Highest pTbjet reconstruction • Results for plot: • chi-square: 9.818 • p-value: 0.7753 • ndf: 14 • chi/ndf: 0.7012
2nd Highest pTbjet reconstruction • Results for plot: • chi-square: 13.66 • p-value: 0.5517 • ndf: 15 • chi/ndf: 0.9107
Dijet Mass reconstruction • Results for plot: • chi-square: 15.47 • p-value: 0.6297 • ndf: 18 • chi/ndf: 0.8594
MET • Results for plot: • chi-square: 15.87 • p-value: 0.1971 • ndf: 12 • chi/ndf: 1.323
Closest pTbjet reconstruction • Results for plot: • chi-square: 14.39 • p-value: 0.2123 • ndf: 11 • chi/ndf: 1.308
New Event Selection Verification (Only uses MC so Excludes QCD)