Update on W mn Analysis with Int. Lumi. of 6.36 pb-1

Xuefei LiJianbei Liu, Yusheng Wu, Haijun Yang, Bing Zhou and Junjie Zhu

The University of Michigan

UM Diboson Meeting 10/08/2010

2

Int. Luminosity Calculation for Wmn

Run Period Trigger Int.Luminosity (pb)

A-D : 152844-159224 L1_MU6 0.31

E: 160387-161948 EF_mu10_MG 0.999

F: 162347-162882 EF_mu10_MG 1.808

G: 165591-165821 EF_mu10 3.24

Total 6.36

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W mn Selection Cuts

Pre-selection

Runs && Events (at least one lepton with Pt > 10 GeV, |h|<2.7)

GRL + BCID

JetCleaning for MET

Trigger

nVx(nTrks>=3)>0&&Vz<150mm

Muon,Pt>15,|Eta|<2.4,|Zpv|<10mm

Muon,Pt_me>10, dPt<15 GeV

W mn Final Selection

Muon,Pt>20 GeV

Muon,Ptcone40/Pt<0.2

Muon,MET>25 GeV

Muon,MT>40 GeV (W candidates)

4

Staco Event Selection from A-G

Staco W+ W- W+ / W-

Period A-C (16.6 nb-1) 45 23 1.96

Period D (293.3 nb-1) 666 447 1.49

Period E (999 nb-1) 2235 1453 1.54

Period F (1808 nb-1) 4295 2840 1.51

Period G (3.24 pb-1) 8046 5195 1.55

Total (6.36 pb-1) 15287 9958 1.54

W+ / W- ratio from Data (SM ~ 1.5)

5

Muid Event Selection from A-G

Muid W+ W- W+ / W-

Period A-C (16.6 nb-1) 48 22 2.18

Period D (293.3 nb-1) 658 438 1.50

Period E (999 nb-1) 2210 1421 1.56

Period F (1808 nb-1) 4334 2855 1.52

Period G (3.24 pb-1) 8148 5245 1.55

Total (6.36 pb-1) 15398 10003 1.54

W+ / W- ratio from Data (SM ~ 1.5)

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Summary of Observed Data and Estimated

Signal and Backgrounds for 6.36 pb-1 Staco W+ W- Total

Data 15287 9958 25245

MC total 15696 10722 26418

MC Wmn 14689 9838 24527

Background 1007 884 1891

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Summary of Observed Data and Estimated

Signal and Backgrounds for 6.36 pb-1 Muid W+ W- Total

Data 15398 10003 25401

MC total 15787 10791 26528

MC Wmn 14784 9912 24646

Background 1003 879 1882

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Breakup of Background Processes for 6.36 pb-1

Process Staco Muid

Wtn 691 694

ttbar 83 81

Zmm 755 750

Ztt 26 26

Drell-Yan 4 4

Single top 26 26

Di-jet 177 171

* Correction for trigger efficiency not included here!

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Muon PT After Pre-Selection

(Staco)

All

W+ W-

10

Muon PT W Candidates

(Staco)

All

W+ W-

11

Muon hW Candidates

(Staco)

All

W+ W-

12

Muon f W Candidates

(Staco)

All

W+ W-

13

MET After Pre-Selection (Staco)

14

MET W Candidates

(Staco)

All

W+ W-

15

W MT After Muon Isolation Cut

(Staco)

All

W+ W-

16

W MT W Candidates

(Staco)

All

W+ W-

17

W PT After Muon Isolation Cut

(Staco)

All

W+ W-

18

W PT W Candidates

(Staco)

All

W+ W-

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Systematic Uncertainties Luminosity Uncertainty: ~ 11% Signal Acceptance Uncertainty: ~ 6.2%

Trigger efficiency uncertainty ~ 3% (from trigger study)

MET Acceptance ~ 3% Muon ID ~ 2% MC@NLO / Pythia, 4%

Background Estimation Uncertainty: QCD Jet background uncertainty ~ 50% Wtn, Zmm, Ztt, ttbar uncertainty ~ 5%

19

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Estimation of Wmn Cross Section (6.36 pb-1)

s = (Nobs - Nb ) / (L x Acc)

• Using Staco Muon Reconstruction Algorithm (W+): s = 5.99 nb ± 0.05 (stat) ± 0.76 (syst) • Using Staco Muon Reconstruction Algorithm (W-): s = 3.97 nb ± 0.04 (stat) ± 0.50 (syst) • Using Staco Muon Reconstruction Algorithm (Inclusive): s = 9.96 nb ± 0.06 (stat) ± 1.26 (syst)

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SM W mn cross-section: 10.46 nb (NNLO)

21

Estimation of Wmn Cross Section (6.36 pb-1)

s = (Nobs - Nb ) / (L x Acc)

• Using Muid Muon Reconstruction Algorithm (W+): s = 6.00 nb ± 0.05 (stat) ± 0.76 (syst) • Using Muid Muon Reconstruction Algorithm (W-): s = 3.96 nb ± 0.04 (stat) ± 0.50 (syst) • Using Muid Muon Reconstruction Algorithm (Inclusive): s = 9.98 nb ± 0.06 (stat) ± 1.26 (syst)

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SM W mn cross-section: 10.46 nb (NNLO)

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L1 Trigger Efficiency with Tag-and-Probe Method

L1_MU6 Run Period ABCD Run Period F MC: Zmm with Pileup

MC: ZmmWithout Pileup

Barrel 0.713 (201/282) 0.736 (168/228) 0.788 (38686/49072)

0.788 (38314/48610)

Endcap 0.843 (242/287) 0.923 (286/310) 0.948 (50295/53083)

0.948 (49901/52642)

L1_MU10 Run Period ABCD Run Period F MC: Zmm with Pileup

MC: ZmmWithout Pileup

Barrel 0.713 (201/282) 0.731 (166/227) 0.787 (38608/49031)

0.787 (38232/48555)

Endcap 0.843 (242/287) 0.916 (282/308) 0.944 (49965/52915)

0.945 (49579/52476)