W/Z  SM approval report

1. Al Goshaw(1) , Andrea Bocci(1) , Miaoyuan Liu(1) Will DiClemente(1),, ZongjinQian(1), Joshua Loyal(1) Song-Ming Wang(2) , SuenHou(2) , Dong Liu(2), ZhiliWeng(2) He Liang(3), Hongye Song(3) , Ming-hui Liu(3),EvgenySoldatov(4), Stephen Gibson(5) ,Louis Helary(6), TianFeng(7), Zhijun Liang(8), W/Z SM approval report Duke University Academia Sinica University of Science and Technology of China Moscow Engineering Physics Institute CERN LAPP-Laboratoire d'Annecy-le-Vieux de Physique des Particules Columbia University University of Oxford

2. Introduction TGC • W+ production ISR FSR s-channel u/t-channel • W measurement can probe WW triple gauge boson coupling (TGC) vertex •  from s-channel tends to have higher Pt • If presence of anomalous TGC from new physics, could enhance W production rate, particularly at the high  Pt region. • Analysis : select events with 1 isolated lepton (e,) , 1 isolated photon, large ETmiss • Main background: • W+jets (jet fakes as ) • Z+/jets (one lepton not Id, jet mis-Id as ) • ttbar production : ATLAS note on MC simulation of W production ATL-COM-PHYS-2010-296 2

3. Event Selection

4. W+jet background in Wγ analysis • Photon isolation in data is systematically higher than isolation in MC • Data driven W+jet background estimation • Non-tight Control region to obtain photon isolation template for W+jet : • Require photon candidates to fail at least two strip layer photon ID cuts

5. Z+jet background in Zγ analysis

6. Lepton isolation and photon jet background • Observe excess in data on lepton in lepton isolation distribution • Indication of photon jet background in both electron and muon channel. • The feature of photon jet background : • No real Missing ET • Bad Lepton isolation , lepton is from jet fake • Good photon isolation, photon is real • Mostly from heavy flavor (γ+b/c jet) for muonchannle • Background shape : • Control region for Electron channel : • low MET region ( loose ,non-medium electron) • Control region for Muon channel : • low MET region • High pT Lepton track with large impact parameter (heavy flavor)

7. Control regoin definition : Systematics of Wjet (Zjet) / γjet background Varying Non-tight defintion: failed at least two strip cuts failed at least one strip cuts failed at least three strip cuts Varying Non-isolated defintion: E_iso(γ)>7GeV E_iso(γ)>8GeV E_iso(γ)>6GeV Nomial: Nomial: Wjet γjet

8. 2D sideband Systematics: correlations between two discriminating variables • 2D sideband assume no correlations photon shower shape and photon isolation • Study such corrections for fake photons in Wjet background Monte Carlo • Define Rwjet as correlation factor, Rwjet=1 means no correlation. • Rwjetin MC is consistent with 1 within 2~3 sigma • Take the maximum variations of Nwjet as systematic (w/wo considering Rwjet) Wjet • 2D sideband assume no correlations between MET and lepton isolation • Study such corrections in γjet dominated control region in data • Define Rγjet as correlation factor, Rγjet=1 means no correlation. • Study Rγjet in γjet dominated control region in data: • EF_2g20_loose trigger , at least one tight+ isolated photon • At least one loose and failed medium electron. • Take the maximum variations of Nγjetas systematic (w/woRγjet) γjet

9. Wγ Background estimation summary Zγ

10. Wγ control plot : photon pT Electron channel >=0jet =0jet Muon channel

11. Wγ control plot : lepton pT and MET Electron channel >=0jet =0jet Muon channel

12. Zγ control plot

13. Phase space definition

14. Photon efficiency uncertainty

15. Uncertainty on Electron isolation efficiency • Data driven isolation efficiency measurement • Select Z->e+e- events using electron tight cut • Only use leading electron for study • Rather pure electron sample >99% purity • In time pileup : • study with different Number of primary vertex • Out-of-time pileup : • study with candidates with • different Bunch trains positions • pT dependence

16. Uncertainty on Photon isolation efficiency

17. JET/ MET acceptance uncertainty

18. Overall uncertainty on detector effect Electron channel Muon channel

19. Overall uncertainty on acceptance

21. Parton and particle level SM prediction Use MCFM to obtain SM NLO prediction in parton level Correct them to particle level Systematic uncertainty from parton to particle corrections

22. Wg Cross section measurement result ( low pT region) =0jet >=0jet

23. WγCross section measurement result ( medium pT region) >=0jet =0jet Electron channel Muon channel

24. Wg Cross section measurement result ( high pT region) >=0jet =0jet Electron channel Muon channel

25. Zg Cross section measurement result >=0jet =0jet Electron channel Muon channel pT>15GeV pT>60GeV

26. Summary of fiducial cross section SM (inclusive) SM (0jet)

27. TGC Anomalouscoupling limit • W+ production • Z+ production • Z-Z-γ(Z-γ-γ) coupling is forbidden in SM model • h3_γ and h4_γ are coupling parameter for Z-Z-γ • H3_Z and h4_Z are coupling parameter for Z-γ-γ s-channel u/t-channel

28. Anomalouscoupling limit in Wγ Use highestpTbinin fiducialmeasurement for ATGC study Δκ=0.4 (0jet) SM (0jet)

29. Bayesian limit setting : ATGC Hypothesis : input from fiducial measurement : possibility of one certainty ATGC Hypothesis given our Measurement as input Lower limit Upper limit

30. Background estimation in high pT region

31. Systematics coupling limit in Wγ

32. Result of ATGC in Wγ

33. Systematics coupling limit in Zγ

34. Result of ATGC in Zγ

35. Backup

36. Systematics coupling limit in Wγ

39. Wgamma : AlpgenJimmyWgammaNpX (117410-117415) • Normalize AlpgenNp(Np0+Np1) to Sherpa_Wmunugamma(0+1jet) • Get k-factor=1.488, apply to all Alpgen samples( Np0~Np5) • Cross section(by summing up Np0 ~Np5) = 83.2 pb • Zgamma : Sherpa_Zmumugamma(0+1jet) (126016) • Use cross section from Sherpa = 14.7 pb • Jet Faking photon : using data-driven method for normalization • Take shape from non-tight photon control region MC Samples for Signal & Jet Faking Photon BackGround

42. Jet multiplicity for Zg pT>15GeV pT>60GeV pT>15GeV pT>60GeV