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ttbar  τ + jets : Update on QCD Estimation. William Edson SUNY at Albany. All Four Histogram Fit Selection. Results for Fit: Signal Fraction: 0.666737±0.038823 Chi2: 65.723 Meas. Used: 69 σ : 164.427±9.574 Ensemble Results: Mean: 0.608899±0.00123928 chi2: 4.49706 NDF: 8.

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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


All Four Histogram Fit Selection

  • Results for Fit:

    • Signal Fraction: 0.666737±0.038823

    • Chi2: 65.723

    • Meas. Used: 69

    • σ: 164.427±9.574

  • Ensemble Results:

    • Mean: 0.608899±0.00123928

    • chi2: 4.49706

    • NDF: 8


Only MET and Dijet Mass Fit Selection

Input Fraction 0.639599

  • Results for Fit:

    • Signal Fraction: 0.639599±0.0435993

    • Chi2: 28.0518

    • Meas. Used: 32

    • σ: 157.735±10.7522

  • Ensemble Results:

    • Mean: 0.610350±0.00123522

    • chi2: 5.81292

    • NDF: 7


Only MET and Highest bjet Reconstruction Fit Selection

  • Results for Fit:

    • Signal Fraction: 0.627044±0.0438223

    • Chi2: 29.579

    • Meas. Used: 32

    • σ: 154.638±10.8072

  • Ensemble Results:

    • Mean: 0.594567±0.00124826

    • chi2: 10.4607

    • NDF: 9


Only MET and 2ndbjet ReconstructionFit Selection

  • Results for Fit:

    • Signal Fraction: 0.634902±0.0427204

    • Chi2: 34.5105

    • Meas. Used: 31

    • σ: 156.576±10.5355

  • Ensemble Results:

    • Mean: ?

    • chi2: ?


MET, Dijet Mass and Highest bjetReconstruction Fit Selection

  • Results for Fit:

    • Signal Fraction: 0.65095±0.0415496

    • Chi2: 44.576

    • Meas. Used: 51

    • σ: 160.534±10.2467

  • Ensemble Results:

    • Mean: 0.609824±0.00122732

    • chi2: 4.50061

    • NDF: 7


MET, Highest and 2nd Reconstruction Fit Selection

Input Fraction 0.627044

  • Results for Fit:

    • Signal Fraction: 0.646003±0.0407967

    • Chi2: 51.0783

    • Meas. Used: 50

    • σ: 159.314±10.0611

  • Ensemble Results:

    • Mean: 0.571676±0.00122598

    • chi2: 6.46039

    • NDF: 8


Back-up


Histograms Used in Fit Comparisons

MET

Dijet Mass


Histograms Used in Fit Comparisons

Highest pTbjet Reconstruction

2nd Highest pTbjet Reconstruction

The other background histograms titled incorrectly due to error in the analysis code, has been corrected.


New Fits for Ensemble Tests


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


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: 18.798

    • p-value: 0.4044

    • ndf: 18

    • chi/ndf: 1.044


2nd Highest pTbjet reconstruction

  • Results for plot:

    • chi-square: 20.82

    • p-value: 0.2346

    • ndf: 17

    • chi/ndf: 1.225


Dijet Mass reconstruction

  • Results for plot:

    • chi-square: 12.06

    • p-value: 0.8829

    • ndf: 19

    • chi/ndf: 0.6347


Closest pTbjet reconstruction

  • Results for plot:

    • chi-square: 8.373

    • p-value: 0.93697

    • ndf: 16

    • chi/ndf: 0.5233


New Event Selection Verification


Linear Fit To Mean Values

y(0): 0.0121648±0.00477388slope: 0.927763±0.00910238

chi2: 7.63631NDF: 7


Linear Fit To All Fractions

y(0): 0.00762894±0.00158121slope: 0.935856±0.00280988

chi2: 42.6259NDF: 8998


MT Plots


Function Fits of QCD Templates

Mean: 171.283 ± 5.986


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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