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ttbar  τ + jets : Update on QCD Estimation

ttbar  τ + jets : Update on QCD Estimation. William Edson SUNY at Albany. Comparison of Tau Truth Matching Results. Previous. New (from Hasib ). True tau if mc object has pdgID value of 15 and within Δ R < 0.2 Output events (integral): 16272 Efficiency: 0.001405.

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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. Comparison of Tau Truth Matching Results Previous New (from Hasib) • True tau if mc object has pdgID value of 15 and within ΔR < 0.2 • Output events (integral):16272 • Efficiency: 0.001405 • In addition, must check mc daughter particles to ensure not lepton and subtract nu 4-vector from mc object to produce visible tau for ΔR < 0.2 check • Output Events (integral): 1151 • Efficiency: 9.937x10-5 • Loss: 92.9%

  3. Major cause of Decrease? Visible tau correction Leptonic child removal • Output: • 16272 • Output: • 1150 • The reason behind the drastic drop is therefore the lepton children check.

  4. MC Tau Plots MC Tau Children Count MC Tau Count MC Tau Children pdgID LeptonicpdgID values: e → 11, μ → 13, τ → 15

  5. Back-up

  6. My Tau Truth Match code 1 intTNtupleAnalyzer::getTruthMatch(float eta, float phi, intpdgid, float *tr_eta, float *tr_phi, float *tr_pt, float *tr_E){ #ifdef _MCEVT for(unsigned int it=0; it < physics->mc_pt->size(); it++){ if ( ( fabs(physics->mc_pdgId->at(it))!= pdgid ) ) continue; if ( physics->mc_child_index->at(it).size() <= 1) continue; boolhasLepChild = false; for ( unsigned intisd = 0; isd < physics->mc_child_index->at(it).size(); isd++ ) { constint child = physics->mc_child_index->at(it).at(isd); intchildVal = fabs(physics->mc_pdgId->at(child)); if (childVal == 11 || childVal == 13 || childVal == 15) hasLepChild = true; } if (hasLepChild == true){ continue; } TLorentzVectorvis; vis.SetPtEtaPhiE(physics->mc_pt->at(it), physics->mc_eta->at(it), physics->mc_phi->at(it), physics->mc_E->at(it));

  7. My Tau Truth Match code 2 for (unsigned intisd = 0; isd < physics->mc_child_index->at(it).size(); isd++ ) { constint child = physics->mc_child_index->at(it).at(isd); if (fabs(physics->mc_pdgId->at(child)) == 16) { TLorentzVector nu; nu.SetPtEtaPhiE(physics->mc_pt->at(child), physics->mc_eta->at(child), physics->mc_phi->at(child), physics->mc_E->at(child)); vis -= nu; break; //saves cpu, but more importantly: avoid duplicates } } if ( isOverlap(eta, phi, vis.Eta(), vis.Phi()) ){ if (tr_eta && tr_phi){ *tr_eta= vis.Eta(); *tr_phi= vis.Phi(); } return 1; } } #endif return 0; }

  8. Comparison Plots: matched Dijet Previous New

  9. Comparison Plots: matched MET Previous New

  10. Comparison Plots: unmatched Dijet Previous New

  11. Comparison Plots: unmatched MET Previous New

  12. Only MET and Dijet Mass Fit Selection • Results for Fit: • Signal Fraction: 0.639599±0.0435993 • Chi2: 26.7843 • Meas. Used: 32 • σ: 157.735±10.7522 • Corrected Results: • Signal Fraction: 0.674161±0.0435993 • σ: 166.258±10.7522 • Correction Systematic: ±2.524995

  13. Linearity Testto All Values Slope: 1.11206 ± 0.00197307 y-intercept: -0.110109 ± 0.00111031 Chi2: 21.0176 NDF: 8998

  14. Linearity Testto Means Slope: 1.10837 ± 0.00203573 y-intercept: -0.106914 ± 0.00128895 Chi2: 134.465 NDF: 7

  15. MT Signal vs Control vs MC Backgrounds Samples Normalized to Own Integrals Samples Normalized to Sum of Integrals

  16. Histograms Used in Fit Comparisons MET Dijet Mass

  17. 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.

  18. New Fits for Ensemble Tests

  19. 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

  20. 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

  21. 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

  22. Highest pTbjet reconstruction • Results for plot: • chi-square: 18.798 • p-value: 0.4044 • ndf: 18 • chi/ndf: 1.044

  23. 2nd Highest pTbjet reconstruction • Results for plot: • chi-square: 20.82 • p-value: 0.2346 • ndf: 17 • chi/ndf: 1.225

  24. Dijet Mass reconstruction • Results for plot: • chi-square: 12.06 • p-value: 0.8829 • ndf: 19 • chi/ndf: 0.6347

  25. Closest pTbjet reconstruction • Results for plot: • chi-square: 8.373 • p-value: 0.93697 • ndf: 16 • chi/ndf: 0.5233

  26. New Event Selection Verification

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