Update on H→WW→2μ2ν Update on H→WW→2μ2ν Oct. 8, 2010 IFCA – U. Oviedo

The work is going on in the HWW and WW analysis (focusing muons in the final state) We keep ourselves synchronized The list of Task proposed during last meeting is almost completely covered: Monte Carlo Trigger Tag and Probe Fake Rates Jet Veto Top tagging Drell-Yan estimation Plus Multivariate Techniques (BDT) in WW and HWW Introduction Rebeca Gonzalez Suarez (08/10/2010)2

WW synchronization The μμ channel was already synchronized: Rebeca Gonzalez Suarez (08/10/2010) CutsGuillelmoDimaUs p T > 20/20, |  |<2.4, q 1 *q 2 < d0d Isolation ID Conversion rejection tcMET > M inv > | M inv | > Projected tcMET > 20 && tcMET > PF Jet Veto (E T > 20 && |  | < 3.0) Soft muon veto Extra Lepton Veto

WW synchronization Rebeca Gonzalez Suarez (08/10/2010) Cutseeee (us)eμeμ (us) p T > 20/20, |  |<2.4, q 1 *q 2 < d0d Isolation ID Conversion rejection tcMET > M inv > | M inv | > Projected tcMET > 20 && tcMET > PF Jet Veto (E T > 20 && |  | < 3.0) Soft muon veto Extra Lepton Veto Also synchronized in ee and eμ:

Updated selection for WW Some changes were proposed for the WW analysis: – Use of a tighter cut in the projected MET – Open the η of the jets from 3 to 5 – Muon P T range from 20/20 to 10/20 (2 regions) The HWW analysis is planned to go as close as possible the the WW analysis : – We don’t use the projected MET (yet, will be studied) – The P T range in Higgs is already 10/20 – We can implement the change in the η of the jets considered for the CJV (that should be identical) Rebeca Gonzalez Suarez (08/10/2010)5

Effect of the proposed selection Rebeca Gonzalez Suarez (08/10/2010) CutsV 0.0V 1.0 Muon Selection tcMET > M inv > | M inv | > Projected tcMET > 20/35 && tcMET > PF Jet Veto (E T > 20 && |  | < 3/5) Soft muon veto Extra Lepton Veto Gain of ~ 30% for signal Monte-Carlo WW Spring10 sample Baseline WW analysis (WW sample, μμ channel) 6

The new selection in perspective Rebeca Gonzalez Suarez (08/10/2010) CutsWWWW (new) tt (new) Zμμ (new) Muon Selection tcMET > M inv > | M inv - M Z | > Projected tcMET && tcMET PF Jet Veto Soft muon veto Extra Lepton Veto Normalizing to 7TeV For WW signal and some of the main processes to be studied 30% better in signal, similar for top and effective against Zμμ With 100pb -1, it will mean the selection of more than one signal event (~6), with < 2 events of background 7

Status of the HWW analysis Rebeca Gonzalez Suarez (08/10/2010) Following WW direction: Muon selection becomes identical (10/20) Same MET (Track corrected) Same Jets for the Central Jet Veto (PF, |η| 20) Test of the cut evolution 3.1pb -1 QCD, W+jets, Z+jets, top, WW, WZ, ZZ, tW included 8 Cross-sections × BR (leptons) for Higgs signal < 1 pb (NNLO) selection efficiencies of the analysis at muon selection level are < 10% (for μμ) : with 10 pb -1 at muon selection < 0.9 Higgs events (160) expected in this channel MHMH σ×BR (pb -1 )

Kinematical distributions Rebeca Gonzalez Suarez (08/10/2010) Everything in good shape Still far from the start of the real the work here 3.1 pb -1 After CJV 9

Trigger Studies Rebeca Gonzalez Suarez (08/10/2010)10 Some examples for 2E31 trigger Menu, performed with pre5 RelVal samples in next slide (with tt Fastsim, no HWW available) lowest unprescaled: HLT_Mu11 HLT_Ele17_SW_CaloEleId_L1R  high eff. for dilepton final states Would like to study new triggers in 1E32 table  samples? Some examples for 2E31 trigger Menu, performed with pre5 RelVal samples in next slide (with tt Fastsim, no HWW available) lowest unprescaled: HLT_Mu11 HLT_Ele17_SW_CaloEleId_L1R  high eff. for dilepton final states Would like to study new triggers in 1E32 table  samples? Electron and muon triggers systematically checked for each table once samples are available Check results can be found in the twiki And in the offline DQM GUI DQMGUI Example Next: Waiting for Higgs to WW samples

Rebeca Gonzalez Suarez (08/10/2010)11 HLT_Mu1 1 HLT_Ele17_SW_CaloEleId Efficiency definition: fraction of selected events passing HLT requirement (top selection eμ) Trigger Efficiencies Efficiency Vs η and P T

Tag and Probe Rebeca Gonzalez Suarez (08/10/2010)12 Tag: -GlobalMuonPT -TrackerMuon -HLT_Mu9 -|η| < 2.1 -p T > 20 GeV -|d 0 | < 0.2 -Isolated -GM normalized χ 2 < 10 -At least one pixel hit -Segments matched in at least 2 muon stations -At least one muon hit matched to the global fit -Number of tracker hits > 10 Tag: -GlobalMuonPT -TrackerMuon -HLT_Mu9 -|η| < 2.1 -p T > 20 GeV -|d 0 | < 0.2 -Isolated -GM normalized χ 2 < 10 -At least one pixel hit -Segments matched in at least 2 muon stations -At least one muon hit matched to the global fit -Number of tracker hits > 10 Probes: Tracks with p T > 5 GeV Probes: Tracks with p T > 5 GeV Passing probes: -GlobalMuonPT -TrackerMuon -|  | < 2.4 -p T > 20 GeV -|d 0 | < Isolated -At least one muon hit matched to the global fit -Number of tracker hits > 10 Passing probes: -GlobalMuonPT -TrackerMuon -|  | < 2.4 -p T > 20 GeV -|d 0 | < Isolated -At least one muon hit matched to the global fit -Number of tracker hits > Z  VBTF cuts Monte Carlo: Zmumu Summer10 sample With all certified data up to now: 4.43 pb -1 (/Zmumu/Summer10-START36_V9_S09- v1/GEN-SIM-RECO)

Muon ID + Iso 13Rebeca Gonzalez Suarez (08/10/2010) Efficiency of the Muon ID + isolation cuts, obtained in data Vs Monte-Carlo, as a function of the P T of the ‘Probe’ And as a function of the η of the ‘Probe’

Trigger Efficiency using T&P Trigger efficiency defined as the fraction of muon fulfiling all the muonID + Isolation criteria and matching a HLT_Mu9 object Data:MC: 14Rebeca Gonzalez Suarez (08/10/2010)

The work started with the very early data Last time we presented this: It was a single muon rate measured in data with less than 15 nb -1 using tracks The data available and the Monte Carlo were in agreement Fake Rates Rebeca Gonzalez Suarez (08/10/2010)15 Higgs contribution to MUO

l+d method For WW and Higgs to WW, we have a method extensively studied in the CSA07 context oriented to the estimation of the W+jets background in di-muon final states Well known and documented: CMS AN 2008/039 Several talks about it available, for example (8 June): – d= d=88524 Basically the idea is to look at QCD events with one good muon and look at the ‘fakeable objects’ that can be mistaken as a second muon (background in the analysis) It is already possible to start the study in data Rebeca Gonzalez Suarez (08/10/2010)16

First Results with 4.43 pb -1 Cleaning the data sample from W, Z and top events (loose VBTF and top selections) Using the JetMet, JetMETTau and Jet datasets Comparing with QCD inclusive Mu 15 Rebeca Gonzalez Suarez (08/10/2010)17 Still lacking statistics in some P T bins to fully perform it The QCD selection in data can also be done in a better way (on going)

Next Step in Fakes But that’s not all: Parallel fake rate study done within the group for top (see 963) Slightly different approach We are working in merge the two concepts in one that can be applied in all the analysis, HWW, WW and top Rebeca Gonzalez Suarez (08/10/2010)18 Yesterday’s talk in top dilepton meeting by Alicia

Jet Veto/Track Jets/b-tagging Studies continuously going on by Lara (many presentations) For 1fb -1 and the three final states together (μμ, eμ and ee) Applying the WW baseline selection (including softmuon) Two b-tagging algorithms tested: – Track Counting (TC) – Secondary Vertex efficiency (SV) Summer 10 samples Rebeca Gonzalez Suarez (08/10/2010)19 VVVV (TC)VV (SV)ttbarttbar (TC)ttbar(SV) Events Reduction 3.0%0.4%43.2%14.8% Little effect on the signal while greatly reducing the ttbar background /VVJets_7TeV-madgraph/Summer10-START36_V10-v1/GEN-SIM- RECO /TTbar/Summer10-START36_V9_S09-v1/GEN-SIM-RECO TrackCounting  More efficient/less purity Secondary Vertex  More purity/less efficiency Even if both algorithms are HighEff…

Tagging efficiencies Track counting High Efficiency algorithm Based on the requirement of a minimum number of good quality tracks with an impact parameter significance exceeding a given threshold. High Eff Simple Secondary Vertex Reconstructs the B decay vertex using an adaptive vertex finder, and then uses variables related to it, to calculate its btagging discriminant. As a function of the btagging discriminant Btagging efficiency Mistag rate Btagging efficiency Mistag rate 20Rebeca Gonzalez Suarez (08/10/2010)

Tagging efficiencies Track counting High Efficiency algorithm High Eff Simple Secondary Vertex algorithm All jets (PF Jets) are inside |  | < 2.5 As a function of the jet E T 21Rebeca Gonzalez Suarez (08/10/2010)

b-tagging PF Jets E T VV (TC) VV (SSV) Ttbar(TC) Ttbar (SSV) 0 GeV GeV GeV GeV Cut on the E T of the jets used as input for the btagging (after CJV) Results without b-tagging (including softmuon cut) assuming 1 fb -1 VV  TTbar  23.0 Applying b-tagging /VVJets_7TeV-madgraph/Summer10-START36_V10-v1/GEN-SIM- RECO /TTbar/Summer10-START36_V9_S09-v1/GEN-SIM-RECO 22Rebeca Gonzalez Suarez (08/10/2010)

HWW Multivariate Analysis (BDT) We keep as up to date as possible the multivariate analysis for HWW and WW We are starting to check the behavior of the data using our latest Training Still need more statistics to fully prepare a dedicated training for 7 TeV -> Very early preliminary studies with data Rebeca Gonzalez Suarez (08/10/2010)23 ttZ Example of the Higgs trainings at 7 TeV against WW, tt and Z+jets with data with 3.1pb -1 (not yet optimized) WW

Summary Work ongoing in most of the main tasks of the WW and HWW analysis: Synchronized and in-tune with the HWW and WW working groups Trigger Validation done in every new release Effort focused in Tag and Probe, Fake rates and top background estimation (CJV, Track jets and b-tagging) Cut-based Analysis for WW and HWW is ready for the data Continuous work in the Multivariate Analysis (BDT) Also a Particle Flow study based in Particle Flow Muons, Met and Jet is going on (coming soon) Rebeca Gonzalez Suarez (08/10/2010)24

Backup

b-tagging (TCHighEfficiency) trackJets PF Jets JPT caloJets 26Rebeca Gonzalez Suarez (08/10/2010)

b-tagging (HighEffSimpleSecondaryVertex) trackJets PF Jets JPTcaloJets 27Rebeca Gonzalez Suarez (08/10/2010)