October 2007

Goal

  • Study supersymmetry refering to P-TDR II
  • Study Top-pair production as signal in both semi-leptonic channel and fully hadronic channel with reference to CMS notes

CMS Notes

Summary

Notes

  • Di-leptonic channel
  • Semi-leptonic channel
  • Fully hadronic channel ( BR ~ 46% )
    • pp->ttbar->bbbar+jjjj ( b,q1,q1bar + bbar,q2,q2bar)
    • At least six jets ( 6 <= Njets <= 8 )
    • Huge QCD backgrounds ( 50 < Pt < 470 GeV/c (QCD) )
    • Triger preselection
      • L2 - jet reconstruction with for following minimal Et thresholds
        • 1-jet or 2-jet events : 350 GeV Et for highest-Et jet
        • 3-jet events : all 3 jets with at least 150 GeV Et
        • 4-jet events : all 4 jets with at least 55 GeV Et
      • L2.5 - b-tagging based on fast pixel track and vertex reconstruction as ingredients, on the two most energetic jets requiring 2 tracks with impact parameter significance exceeding 2sigma
      • L3 - b-tagging based on regional full track reconstruction and same vertex reconstruction as ingredients, on the two most energetic jets requiring 3 tracks with impact parameter significance exceeding 2.5sigma
    • Event selection
      1. 6 <= Njets <= 8
      2. |η| < 2.4
      3. Et > 30 GeV/c
      4. Useful variables with the corresponding cuts applied in sequence are :
        • centrality : C >= 0.68
        • aplanarity : A >= 0.024
        • sum of non-leading jets >= 148 GeV/c
    • Event selection based on neural net
    • Kinematic Top-mass reconstruction with fully hadronic events
      • Good Jet-parton matching : Each of six partons and jets differ only by 15[deg] and jet-reconstructed tops also differ only by 15[deg] from their corresponding parton-level direction
      • Correct Jet-pairing
      • Top-choice
      • Mass determination

Supersymmetry

  • Supersymmetry, an introduction with conceptual and calculational details , Muller-kirsten
  • 초대칭성 물리학 입문 Basic Concepts of Supersymmetry , 오선근
-- SangUnAhn - 26 Oct 2007
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Topic revision: r6 - 2014-07-22 - GunmoRyu
 
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