T. Dai, J. Liu, L. Liu, Y. Wu, B. Zhou, J. Zhu Update of WW ATGC Haijun Yang T. Dai, J. Liu, L. Liu, Y. Wu, B. Zhou, J. Zhu ATLAS SM EW Meeting October 7, 2011

H. Yang - Anomalous TGC Limits What’s New WW ATGC limits vs different binning (optimization) 1bin (total event, >20 GeV) 2bins (20-100 GeV, >100 GeV) 5bins (20-40,40-60,60-80,80-100,>100 GeV) 6bins (20-40,40-60,60-80,80-100,100-120,>120 GeV) 8bins (20-40,40-50,50-60,60-70,70-80,80-100,100-120,>120 GeV) 10bins (20-30,30-40,40-50,50-60,60-70,70-80,80-90,90-100,100-120,>120 GeV) Include leading lepton Pt bin-by-bin uncertainty (see Jianbei’s talk) H. Yang - Anomalous TGC Limits

ATGC Limits(95%CL) with LEP Constraint  Fit anomalous TGCs using leading lepton Pt with different binning  No systematic errors are considered for these limits  6-bin keeps the lepton Pt spectrum and yields good sensitivity Fit PTl (LEP) - MC DkZ lg = lZ Dg1Z Infinity CTEQ6M (1-bin) [-0.165, 0.149] [-0.176, 0.158] [-0.120, 0.176] Infinity CTEQ6M (2-bin) [-0.050,0.034] [-0.054,0.036] [-0.011,0.068] Infinity CTEQ6M (5-bin) [-0.052,0.037] [-0.055,0.040] [-0.012,0.071] Infinity CTEQ6M (6-bin) [-0.051,0.037] [-0.054,0.040] [-0.012,0.070] Infinity CTEQ6M (8-bin) [-0.055,0.042] [-0.058,0.045] [-0.017,0.074] Infinity CTEQ6M (10-bin) [-0.064,0.052] [-0.067,0.056] [-0.025,0.083] H. Yang - Anomalous TGC Limits 3 3

ATGC Limits(95%CL) with LEP Constraint  Fit anomalous TGCs using leading lepton Pt with different binning  Include systematic errors (3% for bin-by-bin shape uncertainty)  6-bin keeps the lepton Pt spectrum and yields good sensitivity Fit PTl (LEP) - Data DkZ lg = lZ Dg1Z Infinity CTEQ6M (1-bin) [-0.240, 0.224] [-0.256, 0.238] [-0.189, 0.245] Infinity CTEQ6M (2-bin) [-0.064,0.048] [-0.069,0.051] [-0.024,0.080] Infinity CTEQ6M (5-bin) [-0.065,0.050] [-0.068,0.054] [-0.024,0.083] Infinity CTEQ6M (6-bin) [-0.063,0.048] [-0.066,0.052] [-0.022,0.081] Infinity CTEQ6M (8-bin) [-0.067,0.054] [-0.070,0.059] [-0.028,0.085] Infinity CTEQ6M (10-bin) [-0.078,0.067] [-0.081,0.072] [-0.040,0.096] H. Yang - Anomalous TGC Limits 4 4

ATGC Limits(95%CL) with LEP Constraint  Fit anomalous TGCs using one bin Assuming same systematic uncertainty for different Pt cuts. MC expected limits at 95% C.L. Fit PTl (LEP) – MC DkZ lg = lZ Dg1Z Infinity CTEQ6M (Pt>80GeV) [-0.078, 0.063] [-0.084, 0.0.066] [-0.037, 0.094] Infinity CTEQ6M (Pt>90GeV) [-0.073,0.058] [-0.079,0.061] [-0.032,0.089] Infinity CTEQ6M (Pt>100GeV) [-0.071,0.055] [-0.076,0.058] [-0.030,0.086] Infinity CTEQ6M (Pt>110GeV) [-0.069,0.053] [-0.074,0.056] [-0.028,0.085] Infinity CTEQ6M (Pt>120GeV) [-0.067,0.052] [-0.072,0.054] [-0.027,0.083] H. Yang - Anomalous TGC Limits 5 5

Fit Kinematic Distribution (PTl) We use MC truth PT(l+), PT(l-), MET_Rel spectra to determine the 3D reweighting coefficients in each bin (10GeV). Then apply 3D reweighting ratio of a given anomalous couplings to modify event weight of each selected WW event based on MC truth PT(l+), PT(l-), MET_Rel. The reconstructed PTl with modified event weights is used to determine limits of the anomalous couplings. Sensitivity to anomalous couplings mainly comes from high Pt region Last bin includes overflow events H. Yang - Anomalous TGC Limits 6

Binned Likelihood Function Assuming systematic uncertainties of luminosity (sc), signal (ss) and four backgrounds (sb1-b4) are Gaussian and uncorrelated, we convolve six Gaussian distributions with a Poisson distribution to form a binned likelihood function. Systematic uncertainties - Luminosity (sc =3.7%) (correlated uncertainty for all MC) - Signal (ss = 7.6%) - Backgrounds: Wjets (sb1 = 27.8%, data-driven) other diboson (sb2 = 13.1%, MC), Zjets (sb3 = 18.1%, data-driven) Top (sb4 = 30.3%, data-driven), shape error (bin-by-bin ~7-11%) Ns is expected signal events which depends on reweighting function R (as a function of anomalous couplings). H. Yang - Anomalous TGC Limits 7

ATGC Limits with bin-by-bin uncertainty Lepton Pt Bin-by-bin uncertainty (theoretical  Experiemental) Details are described in Jianbei’s talk Pt (GeV) 25-40 40-60 60-80 80-100 100-120 >120 Errors  7.28% 7.68% 7.31% 7.77% 10.81% 8.52% Fit PTl (LEP) MC Dkg DkZ lg = lZ Dg1Z Infinity CTEQ6M (6-bin with errors) [-0.190,0.238] [-0.071,0.057] [-0.075,0.061] [-0.030,0.089] Fit PTl (LEP) Data Dkg DkZ lg = lZ Dg1Z Infinity CTEQ6M (6-bin with errors) [-0.181,0.227] [-0.068,0.054] [-0.071,0.059] [-0.027,0.086] H. Yang - Anomalous TGC Limits

Log-likelihood(LEP) vs ATGC H. Yang - Anomalous TGC Limits

Log-likelihood vs ATGC H. Yang - Anomalous TGC Limits

H. Yang - Anomalous TGC Limits 2D Contour limits H. Yang - Anomalous TGC Limits

H. Yang - Anomalous TGC Limits 2D contour limits H. Yang - Anomalous TGC Limits

Comparisons of ATGC Limits CDF, PRL.104, 201801 (2010) D0 PRL.103, 191801 (2009) CERN-PH-EP/2006-042 hep-ex/0612034 CMS PLB 699 (2011) 25–47 H. Yang - Anomalous TGC Limits

H. Yang - Anomalous TGC Limits Summary  95% C.L. limits on the anomalous TGCs are obtained using WW candidates with 1.02 fb-1 at 7 TeV based on LEP scenario. H. Yang - Anomalous TGC Limits

Backup

PDF/Scale Uncertainty vs Lepton Pt Cutoff Infinity, default scale with different PDFs Cutoff Infinity, default PDF(CTEQ6M) with different scales

Theoretical Uncertainties (from Liu Lulu) From PDF (CTEQ6M,MRST2002NLO,MRST2002NNLO) From factorization/renormalization scale Total Pt (GeV) 20-30 30-40 40-50 50-60 60-70 70-80 80-90 90-100 100-120 >120 Uncert. 0.0687% 0.0277% 0.0020% 0.0123% 0.0275% 0.0223% 0.0194% 0.0237% 0.0735% 0.1378% Pt (GeV) 20-30 30-40 40-50 50-60 60-70 70-80 80-90 90-100 100-120 >120 Uncert.  0.0560% 0.0481% 0.0552% 0.1337% 0.1547% 0.2102% 0.2462% 0.0961% 0.4786% 3.4619% Pt (GeV) 20-30 30-40 40-50 50-60 60-70 70-80 80-90 90-100 100-120 >120   0.09% 0.06% 0.13% 0.16% 0.21% 0.25% 0.10% 0.48% 3.46%

Experimental uncertainties (Jianbei Liu) 20-30 30-40 40-50 50-60 60-70 70-80 80-90 90-100 100-120 >120 Electron Reconstruction SF -0.58 -0.62 -0.63 -0.64 -0.65 -0.67 -0.66 3.08 1.43 1.36 1.55 1.93 2.4 2.96 3.65 3.06 3.3 Electron Identification SF -1.72 -1.4 -1.28 -1.37 -1.36 -1.38 -1.39 -1.35 Electron Et Resolution -0.6 -0.14 0.2 0.21 -0.04 0.25 0.28 -0.97 -0.25 0.26 1.92 2.41 2.95 3.66 Electron Et Scale 0.08 0.18 -0.48 -0.02 -1.17 -1.47 -1.1 -0.09 -1.31 2.94 3.67 3.29 Muon Identification SF -0.83 -0.79 -0.78 -0.77 -0.81 Muon Scale/Resolution from ID -0.17 -0.03 0.06 0.09 0.03 -0.52 0.13 0.38 3.07 3.05 Muon Scale/Resolution from MS -0.39 0.17 0.12 -0.2 0.36 0.41 -0.01 Jet Energy Scale 6.89 6.24 6.94 7.05 6.05 7.29 7.43 7.08 9.56 7.02 3.09 Jet Energy Resolution -3.01 -1.84 -2.21 -3.03 -2.31 -2.06 -0.57 -4.71 -2.54 6.12 2.84 2.7 3.83 4.79 5.89 7.27 6.06 6.55 Total 7.81 6.74 7.48 7.87 6.81 7.82 8.08 7.47 10.8 7.78 Pt (GeV) Syst. Uncert. Associated Stat. Total Syst. Uncert.

H. Yang - Anomalous TGC Limits BHO NLO Generator with Anomalous TGCs (Ref: Baur, Han, Ohnemus, Phys. Rev. D53, 1098, 1996) Three different constraints: LEP assumption (three free parameters) HISZ scenario (two free parameters) Equal couplings assumption (two free parameters) Input parameters to BHO (L (cutoff) = 3,∞ TeV; PDF = CTEQ6M, MRST2002) CME = 7000 GeV Mass_Z = 91.1876 GeV Gamma_Z = 2.4952 GeV Mass_W = 80.403 GeV Gamma_W = 2.141 GeV Mass_top = 172.5 GeV Sin2qW = 0.23 a = 1/128 Br (Wln) = 0.108166 H. Yang - Anomalous TGC Limits 19

Cross-Check: BHO NLO vs MC@NLO Check the SM coupling between MC@NLO and BHO Kinematic distributions from BHO and MC@NLO are consistent. H. Yang - Anomalous TGC Limits 20

Anomalous TGCs Reweighting Method Ref: V.M. Abazov et al. (D0), Phys. Rev. D80, 053012 (2009) Basic idea: differential cross section has quadratic dependence on anomalous TGCs, X is a set of kinematic distributions: LEP parameterization (eg.): Points DKZ DlZ Dg1Z 1 +0.4 2 -0.4 3 +0.5 4 -0.5 5 6 7 8 9 Test for LEP Method using nine ATGCs points: H. Yang - Anomalous TGC Limits 21

BHO ATGC Points for HISZ/EQUAL Parameterization ATGC points, L = 3, ∞ TeV for HISZ scenario parameterization Points DKZ DlZ 1 +0.4 2 -0.4 3 +0.5 4 -0.5 5 0.5 0.4 Test point for HISZ -0.3 Points DKZ DlZ 1 +0.4 2 -0.4 3 +0.5 4 -0.5 5 Test point for EQUAL ATGC points, L = 3, ∞ TeV for EQUAL scenario parameterization H. Yang - Anomalous TGC Limits 22

Validation of 3D Reweighting LEP Scenario: DKZ = +0.1 DlZ = +0.0 Dg1z = -0.1 lep_pT>20 GeV fabs(eta)<1.37 || ( fabs(eta)<2.47 && fabs(eta) >1.52) L1Pt>25 GeV Mll>15 GeV fabs( Mll-Mz)>15 GeV METRel>40 GeV SM aTGC SM_reweighted N_total 443.5 100% 514.2 513.6 N_2l 214.9 48.5% 268.4 52.2% 267.4 52.1% N_L1Pt 211.9 47.8% 265.4 51.6% 264.4 51.5% N_Mll 209.3 47.2% 262.7 51.1% 261.7 51.0% N_MzVeto 160.2 36.1% 209.8 40.8% 209.1 40.7% N_METRel 99.4 22.4% 134.2 26.1% 133.8 H. Yang - Anomalous TGC Limits

Validation of 3D Reweighting Pt(ll) Lepton Eta Mll MtWW H. Yang - Anomalous TGC Limits

Validation of 3D Reweighting MET METRel H. Yang - Anomalous TGC Limits

WW Production at 7 TeV with 1.02 fb-1  Raise leading lepton Pt cut (20GeV  25 GeV) – remove wjets/QCD  Lower jet pt threshold cut (30 GeV  25 GeV) and b-tag veto cut – suppress ttbar, single top and drell-yan background 325 WW events observed using revised WW selection cuts, expect WW 196.6 (SM WW cross section 44.4 pb) and background of 86.6. H. Yang - Anomalous TGC Limits 26

Methods to Determine 95% C.L. Limits Log-likelihood Function (Fmin + 1.92) Bayesian Estimator -0.097 < DkZ < 0.065 +1.92 -0.099 < DkZ < 0.068 95% C.L. Limits determined from two methods are consistent. H. Yang - Anomalous TGC Limits 27