VBF H->tt->lept had Electron Channel 10.0.4 Analysis

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VBF H-gttt-gtlept hadElectron Channel10.0.4
Analysis

• Jaspreet Sidhu
• 27-10-05

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Data Set

• Generation Simulation
• Release 10.0.4
• Rome layout, with TRT simulation
• Digitization Reconstruction
• Release 10.0.4
• Default reconstruction parameters
• Electrons, taus, jets
• R0.4 Cone algorithm for jets
• AOD objects

• - Pythia Tauola Production
• H-gttt , VBF mode
• 20000 Events
• (after filtering)
• MH 115GeV
• t-gt e?? , t-gt h ?
• (s x BR) 390 fb

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Electron Filter

• Use Single High Pt Electron Filter
• No Filter
• 1000 events
• 366 electrons
• Filter
• pt gt15GeV
• ? lt2.7
• 126 electrons
• ? 12.6

• 20000 VBF Higgs events (after filtering)
• 10.0.4 release for simulation
• 10.0.4 for digitization w/o pile-up

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Full simulation Elec ID

• Elec ID ( 3 Basic Cuts)
• cut 1 hasTrack() pT gt20GeV
• cut 2 egamma object
• Comparison of 3 ElecID cuts at Cut 3
• cut 3a isEM 0 (using all the flags
  including TRT)
• cut 3b epiNN gt0.8
• cut 3c likelihood gt 0.8
• Stronger Elec ID cuts
• cut 4 Et conelt10GeV in R0.45
• cut 5 0.8 lt E/p lt1.4

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Electron Reconstruction Efficiency
elec ? ()
Truth 20,000
No Cuts (candidates) 193,146
Cut 1 46,761
Cut 2 21,877
isEM (all flags) 13,891 69.5
epiNN gt 0.8 18,312 91.6
likelihood() gt0.8 16,313 81.6
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Stronger Elec ID Cuts
EoverP
EtCone
Higgs
Dijets
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Harder Cuts Isolation and E/p
elec ? ()
isEM 13,891 69.5
Isolation (EtConelt10GeV) 13,049 65.2
E/p (0.8lt E/P lt1.4) 11,163 55.8
epiNN 18,312 91.6
Isolation 13,096 65.5
EoverP 10,554 52.3
likelihood gt0.8 16,313 81.6
Isolation 14,700 73.5
E/p 11,812 59.1
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isEM
Pt
Eta
After Hard Elec Cuts
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epiNN
Pt
Eta
After Hard Elec Cuts
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Likelihood
Eta
Pt
After Hard Elec Cuts
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Dijet Rejection Best algorithmisEM (refer to
Saminders Work)- Using isEM rather than
likelihood as the 3rd level cut only reduces
Electron Identification by 3.3. - By using
Harder ElecID cuts can reject 87 of
background
Cuts Higgs elec Dijets elec
isEM 13,891 301
Isolation 13,409 99
E/p 11,163 (? 80.4) 39 (? 13.0)
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Taujet Identification

• Taujet is essentially a narrow jet in the
  detector
• Taujet Id Cuts
• cut 1 abs(charge)1
• cut 2 NumTrack 1 or 3
• cut 3 likelihood gt 4
• cut 4 pt gt40 GeV

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Taujet Reconstruction Efficiency
Taujets
Truth 20,000
No Cuts (candidates) 57316
Cut 1 42452
Cut 2 17951
Cut 3 6106
Cut 4 (? 30.5 )
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Taujets
Eta
Pt
After Cut 3
After Cut 4
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Higgs Reconstruction

• Use Identified Electrons and Taujets and
  reconstruct the Invariant Mass of the Tau System
• Use Collinear Approximation
• Using the missing transverse momentum and
  assuming Tau decay products are collinear with
  original Tau, solve 2 linear equations for
  missing neutrinos, can reconstruct the Taus and
  hence the Invariant mass of the whole
  system(Higgs Mass)

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Higgs Reconstruction

• Reconstruct 6062
• events
• Efficiency of Reconstruction
• ? 30.31
• Mean 106.2Gev
• ?14.9 Gev

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Higgs Reconstruction (with hard elecid cuts)

• Reconstructed 6062 events
• Efficiency of Reconstruction
• ? 24.7
• Efficiency drop 5.6
• Mean 106.2Gev
• ? 14.7 Gev

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Fake Higgs

• 6 Fake Higgs reconstructed from
• 201,700 events
• Fake rate
• ? 0.0029
• With Hard Electron cuts
• 2 Fake Higgs
• Reject 66.7 fake higgs
• 2 Fake Higgs

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Summary

• Electron Identification Efficiency (? 69.5)
• With Harder Cuts (? 55.8)
• Dijet Rejection ( Can Reject 87 of electrons)
• Tau Identification Efficiency (? 30.5)
• Higgs Reconstruction Efficiency (? 30.31)
• With Harder Elec Id Cuts (? 24.7)
• 6 Fake Higgs (? 0.0029)
• With Harder Elec Id Cuts (Can reject 66.7 )
• Next Step Reconstruction with pile up and
  Trigger simulation