Fully reconstructed SM 130 GeV Higgs  in the lepton+hadron channel First look at the samples Catalin, Kevin, Tony Univ. of Illinois

MC samples  Higgs  - one tau decays leptonically  rome recov10.H15_130_tautaul  100 files*50 evts= 5k events  CBNT’s and AOD’s in Erik’s area: /share/data8/brubaker/H15/  Worked off the CBNT’s – results from 3k only  (115 GeV Higgs mass samples are in /share/data8/brubaker/H7/ ~4k events).

CBNT info used: Tau ID used TAU block:  Et: tau_etHadCalib+tau_etEMCalib   : tau_eta,  : tau_phi  Require: tau_accept==1 Muon ID used COMB block:  1/Et: fabs(ptircb), cot(  ): cotthrcb,  : phircb Electron ID used EGAM block:  Et: eg_et,  : eg_eta,  : eg_phi  Require: eg_IsEM=0 Missing Et ID used ETmiss block:  Px: MET_ExMissFinal, Py: MET_EyMissFinal Jet ID used CJets block 1111 variables in CBNT!!

Tau ID 28.4% events have at least one tau 24.3% events have exactly one tau In ATLFAST, the assumed efficiency was 10%

e and  ID Require an Et threshold of 10 GeV Events with at least one e: 23.1% (exactly one: 21.7%) Events with at least one  : 36.0% (exactly one: 32.4%) Tau+exactly one lepton: 310 events (131 e  ) = 10.3% - twice the efficiency of ATLFAST sample

 (lead jet)  (sec jet) More distributions

Jets and Missing Et E T (lead jet) E T (sec jet)

Higgs Reconstruction Use collinear approximation to find neutrinos’ momenta Something is going on: 20% of the events have M(Higgs)>300 GeV. Sample with M H =130 GeVSample with M H =115 GeV

Summary Looked at the 130 GeV Higgs->ditau sample Some things look good: tau ID, lepton, jets Questions: –Are we looking at the right variables? –Why so many muons? –Why so many events with M H >300 GeV? To do: redo the ATLFAST trigger study; run over the whole sample; maybe use the truth to answer some of the questions above. Start looking for (and generating) backgrounds

Backup

Default Efficiency Using Erik’s parametrization for the jets –Not for the  jets –For the  triggers use ATLFASTB info, not the ‘truth’ –Given N (N  7) choose the most efficient N triggers: Low luminosity regime: N= 1: (jet+MET) N= 2: (+muon) N= 3: (+electron) N= 4: (+taujet+MET) N= 5: (+1jet) N= 6: (+3jet) N= 7: (+4jet) High luminosity regime: N = (muon) N = (+electron) N = (+jet+MET) N = (+taujet+MET) N = (+1jet) N = (+3jet) N = (+4jet)

This will hurt efficiency FASTSIM: Too few ATLFASTB  -jets!

FASTSIM:  -jets + lepton Wait! It’s even worse: 73% of events with an ATLFASTB  -jet have no leptons. Of the 536 evts that do have both a lepton and a  -jet, about 300 are below the lepton trigger. 1986/50k= 4% - very poor

Adding  +lepton trigger LOLUM Max. increase: 0.5%= ( )/34.3 Max. increase: 2.1% = ( )/24.7 Plot: 100* [ eff ( )-eff ( )] / eff ( )

“Perfect”  -jet identification Max. increase: 6.1%Max. increase: 33.5% = ( )/28.6 Plot: 100* [ eff ( )-eff ( )] / eff ( )

Imperfect  -jet identification Plot: 100* [ eff ( )-eff ( )] / eff ( ) as  -ID efficiency is varied from 10% to 100%. E T (lep)>5GeV E T (  -jet)>5GeV perfect ID ATLFB

Conclusions Rough pass at trigger efficiencies for H  in the lepton+hadron channel Backgrounds? –Top pair production –Bottom pair production –W/Z+jets production –Z  Some (all?) exist; some may have to be generated Study improvements to S/B –Cut on  between lepton and  -jet

Higgs Mass Reconstruction 4.3% events have M H >300