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Events and Events with pileup

signal events:

events with pileup (4.6events):

Comparison of them ( red without pileup)


  • This sample still has 1mm bug, which make electron selection efficiency lower. the pileup existing makes more electrons reconstructed as candidates, but after ID, the effect is negligible. The reconstruction efficiency is ruined by the pileup events.
    • with_wo_pile_ele_isEM.gif
    • pile_wo__electron_dist.gif
    • pile_wo__electron_reco_effi.gif
  • in pile up events, less events pass ID of inner detector and more events pass calorimeter ID
    • with_wo_pile_ele_num_pt.gif


  • muon reconstruction efficiency is deteriorated by pile up events
    • pile_wo__muon_reco_effi.gif
  • more muon candidates are reconstructed affected by pileup events
    • pile_wo__muon_dist.gif


  • the jets pre-calibration parameters taken from signals works not well with events with pile up. The jet energy is not calibrated back to truth quarks, which make low efficiency in cut (>4jets pt>30GeV)
    • pile_wo__jet_reso.gif
  • with pile up, the same b-tag efficiency, the light jet rejection is deteriorated.
  • full_ljrej_btageffi.gif


  • etmiss resolution is deteriorated too by pile up events. etmiss.gif

t and ttbar

  • Due to the unperfect jet calibration, the t and ttbar is reconstructed with lower mass.
    • pile_wo__ttbar_mass_and_reso.gif
    • pile_wo__ttbar_and_t.gif
    • pile_wo__w_t_mass.gif


Topic attachments
I Attachment History Action Size Date Who Comment
Unknown file formatcxx comp_w_wo_pileup.cxx r1 manage 41.1 K 2008-03-12 - 16:16 ChengguangZhu  
GIFgif etmiss.gif r1 manage 20.9 K 2008-03-12 - 16:13 ChengguangZhu  
GIFgif full_ljrej_btageffi.gif r1 manage 12.5 K 2008-03-12 - 16:15 ChengguangZhu  
GIFgif pile_wo__electron_dist.gif r1 manage 15.6 K 2008-03-12 - 16:16 ChengguangZhu  
GIFgif pile_wo__electron_reco_effi.gif r1 manage 17.3 K 2008-03-12 - 16:12 ChengguangZhu  
GIFgif pile_wo__jet_reso.gif r1 manage 28.4 K 2008-03-12 - 16:26 ChengguangZhu  
GIFgif pile_wo__muon_dist.gif r1 manage 14.9 K 2008-03-12 - 16:13 ChengguangZhu  
GIFgif pile_wo__muon_reco_effi.gif r1 manage 17.2 K 2008-03-12 - 16:13 ChengguangZhu  
GIFgif pile_wo__ttbar_and_t.gif r1 manage 20.3 K 2008-03-12 - 16:14 ChengguangZhu  
GIFgif pile_wo__ttbar_mass_and_reso.gif r1 manage 20.1 K 2008-03-12 - 16:14 ChengguangZhu  
GIFgif pile_wo__w_t_mass.gif r1 manage 21.2 K 2008-03-12 - 16:14 ChengguangZhu  
GIFgif with_wo_pile_ele_isEM.gif r1 manage 3.9 K 2008-03-12 - 16:15 ChengguangZhu  
GIFgif with_wo_pile_ele_num_pt.gif r1 manage 14.0 K 2008-03-12 - 16:12 ChengguangZhu  
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Topic revision: r2 - 2008-03-18 - ChengguangZhu
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