ttbar τ + jets : Update on QCD Estimation
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Transcript of ttbar τ + jets : Update on QCD Estimation
ttbar τ + jets:Update on QCD Estimation
William EdsonSUNY at Albany
Linearity Test to All Values
Slope: 1.11206 ± 0.00197307 y-intercept: -0.110109 ± 0.00111031Chi2: 21.0176 NDF: 8998
Linearity Test to Means
Slope: 1.10837 ± 0.00203573 y-intercept: -0.106914 ± 0.00128895Chi2: 134.465 NDF: 7
Ensemble Results Table
Input Fraction Mean Output Fraction
Difference
0.1 -0.000488063 0.100488063
0.2 0.107330 0.092670
0.3 0.221446 0.078554
0.4 0.335789 0.064211
0.5 0.453984 0.046016
0.6 0.565406 0.034594
0.7 0.673945 0.026055
0.8 0.777001 0.022999
0.9 0.883528 0.016472
Only MET and Dijet Mass Fit Selection
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
Input Fraction 0.639599
Only MET and Dijet Mass Fit Selection
Results for Fit: Signal Fraction:
0.623387±0.0391393 Chi2: 26.7843 Meas. Used: 32 σ: 160.198±10.058
Ensemble Results: Mean:
0.591959±0.00103681
chi2: 7.08608 NDF: 7
MT Signal vs Control vs MC Backgrounds
Samples Normalized to Own Integrals
Samples Normalized to Sum of Integrals
Back-up
MT Signal vs Control vs MC Backgrounds
Samples Normalized to Own Integrals
Samples Normalized to Sum of Integrals
Histograms Used in Fit Comparisons
MET
Dijet Mass
Histograms Used in Fit ComparisonsHighest pT bjet Reconstruction
2nd Highest pT bjet ReconstructionThe 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
2
i
iiii2
σ
)n(OB)D)binfrac(QC*N(Remain)*frac(QCD)g)binfrac(si*N(Remain)*(frac(Sig)n(Data)χ
N(OB) - N(Data) N(Remain)
frac(Sig) - 1 frac(QCD)
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 pT bjet reconstruction
Results for plot: chi-square: 18.798 p-value: 0.4044 ndf: 18 chi/ndf: 1.044
2nd Highest pT bjet 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 pT bjet reconstruction
Results for plot: chi-square: 8.373 p-value: 0.93697 ndf: 16 chi/ndf: 0.5233
New Event Selection Verification
Cut Sig Evts
Fakes Sig Eff. Fake Ratio
Rej Fact.
Sig/sqrt(Bkg
d)
Sig/Sqrt(Sig
+Bkgd)
C5Lep Veto
9137 7180594
- - - 3.410 3.408
C6ntaus >
0
9137 1304359
1 0.1817 0.007004
8.000 7.974
C7njets
5051 365445 0.5528 0.2802 0.02500 8.355 8.298
C8MET
4104 36622 0.8125 0.1002 0.1379 21.45 20.34
C9MT
2995 18708 0.7298 0.5108 0.2194 21.90 20.33
C10bjet
2604 4159 0.8694 0.2223 0.7201 40.38 31.66
C12Trig
match
1480 536 0.5684 0.1289 4.858 63.93 32.96
Linear Fit To Mean Values
y(0): 0.0121648±0.00477388 slope: 0.927763±0.00910238chi2: 7.63631 NDF: 7
Linear Fit To All Fractions
y(0): 0.00762894±0.00158121 slope: 0.935856±0.00280988chi2: 42.6259 NDF: 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
start
pass
N
NEff
gen
rec
N
NAcc