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VBF H- > ττ- > lept had Electron Channel 10.0.4 Analysis. Jaspreet Sidhu 27-10-05. Generation + Simulation – Release 10.0.4 – Rome layout, with TRT simulation Digitization + Reconstruction – Release 10.0.4 – Default reconstruction parameters Electrons, tau’s…, jets
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VBF H->ττ->lept hadElectron Channel10.0.4 Analysis Jaspreet Sidhu 27-10-05
Generation + Simulation – Release 10.0.4 – Rome layout, with TRT simulation Digitization + Reconstruction – Release 10.0.4 – Default reconstruction parameters Electrons, tau’s…, jets – R=0.4 Cone algorithm for jets – AOD objects Data Set - Pythia & Tauola Production H->ττ , VBF mode 20000 Events (after filtering) MH = 115GeV τ-> e , τ-> h (σ x BR) = 390 fb
Electron Filter • Use Single High Pt Electron Filter • No Filter • 1000 events 366 electrons • Filter pt >15GeV || <2.7 126 electrons = 12.6% • 20000 VBF Higgs events (after filtering) • 10.0.4 release for simulation • 10.0.4 for digitization w/o pile-up
Elec ID ( 3 Basic Cuts) cut 1: hasTrack() & pT >20GeV 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 >0.8 cut 3c: likelihood > 0.8 Stronger Elec ID cuts cut 4: Et cone<10GeV in R=0.45 cut 5: 0.8 < E/p <1.4 Full simulation Elec ID
Stronger Elec ID Cuts EoverP EtCone Higgs Dijets
isEM Pt Eta After Hard Elec Cuts
epiNN Pt Eta After Hard Elec Cuts
Likelihood Eta Pt After Hard Elec Cuts
Dijet Rejection – Best algorithm:isEM (refer to Saminder’s 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
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 > 4 cut 4: pt >40 GeV
Taujets Eta Pt After Cut 3 After Cut 4
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 Tau’s and hence the Invariant mass of the whole system(Higgs Mass)
Higgs Reconstruction • Reconstruct 6062 events • Efficiency of Reconstruction = 30.31% • Mean =106.2Gev • =14.9 Gev
Higgs Reconstruction (with hard elecid cuts) • Reconstructed 6062 events • Efficiency of Reconstruction = 24.7% • Efficiency drop = 5.6% • Mean =106.2Gev • =14.7 Gev
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 Fake Higgs
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