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Fully reconstructed SM 130 GeV Higgs  in the lepton+hadron channel

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.004315.recov10.H15_130_tautaul 100 files*50 evts= 5k events

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Fully reconstructed SM 130 GeV Higgs  in the lepton+hadron channel

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

  2. MC samples • Higgs - one tau decays leptonically • rome.004315.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). http://atlfarm003.mi.infn.it/%7Enegri/cgi-bin/rome_dataset_ov.cgi?dataset=rome.004315.recov10.H15_130_tautaul,LCGROME

  3. CBNT info used:https://uimon.cern.ch/twiki/bin/view/Atlas/CBNTVariableList • Tau IDusedTAU 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!!

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

  5. 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 + 179 ) = 10.3% - twice the efficiency of ATLFAST sample

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

  7. Jets and Missing Et ET (sec jet) ET (lead jet)

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

  9. 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 MH>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

  10. Backup

  11. 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: High luminosity regime: N= 1: 0000010 0.13598000(jet+MET) N= 2: 1000010 0.24079999(+muon) N= 3: 1100010 0.32436001(+electron) N= 4: 1100011 0.33831999(+taujet+MET) N= 5: 1110011 0.34233999(+1jet) N= 6: 1111011 0.34255999(+3jet) N= 7: 1111111 0.34268001(+4jet) N = 1 1000000 0.12954000 (muon) N = 2 1100000 0.21585999(+electron) N = 3 1100010 0.24330001(+jet+MET) N = 4 1100011 0.24548000(+taujet+MET) N = 5 1110011 0.24738000(+1jet) N = 6 1111011 0.24745999(+3jet) N = 7 1111111 0.24745999 (+4jet)

  12. 105 104 103 105 104 103 This will hurt efficiency • FASTSIM: Too few ATLFASTB -jets!

  13. FASTSIM: -jets + lepton 1986/50k= 4% - very poor 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.

  14. Adding +lepton trigger Plot: 100*[eff (11111111)-eff (11111110)] / eff (11111110) Max. increase: 0.5%= (34.4-34.3)/34.3 Max. increase: 2.1% = (25.3 - 24.7)/24.7 LOLUM

  15. “Perfect” -jet identification Plot: 100*[eff (11111111)-eff (11111110)] / eff (11111110) Max. increase: 6.1% Max. increase: 33.5% = (38.1-28.6)/28.6

  16. Imperfect -jet identification Plot: 100*[eff (11111111)-eff (11111110)] / eff (11111110) as -ID efficiency is varied from 10% to 100%. perfect ID ET(lep)>5GeV ET(lep)>5GeV ET(-jet)>5GeV ATLFB

  17. 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

  18. Higgs Mass Reconstruction 4.3% events have MH>300

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