ATLAS multi-lepton analysis

• LBL Trilepton
• ATL-COM-PHYS-2011-1374: Search for anomalous production of like-sign dilepton events with at least one electron
• ATL-COM-PHYS-2011-1243: Search for Evidence of New Physics in Events with Three Leptons
• ATL-COM-PHYS-2011-960: Search for Evidence of New Physics in Events with Four Leptons
• ATL-COM-PHYS-2011-954: SUSY Searches at ATLAS in Final States with At Least Four Leptons and Missing Transverse Energy

CMS multi-lepton analysis

• CMS Physics Results
• 1106.0933v2: Search for Physics Beyond the Standard Model Using Multilepton Signatures in pp Collisions at sqrt(s)=7 TeV
• talk: CMS searches for R-parity violating SUSY by Richard Carl Gray
• talk: Searches for multi-lepton Production in CMS by Dr. Fedor Ratnikov (KIT - Karlsruhe Institute of Technology (DE))

Reference

• 1110.1368: Backgrounds To Higgs Boson Searches from Asymmetric Internal Conversion
• 1110.4738: Four-lepton production at hadron colliders: aMC@NLO predictions with theoretical uncertainties

lepton selection

• Same-Sign Dimuon

combined Staco muons
normal MCP hit requirements
|eta|<2.5
pT>10
Q_ID == Q_MX
|d0|<0.2
|z0*sin(theta)|<5.0
|d0|/sigma(d0) < 3.0
one muon with pt>20 matches trigger
ptcone40_500/pt < 0.08 && ptcone40_500 < 5.0


µµ-channel: 
   - pt 20/10 GeV
   - |d0|/sigma(d0) < 3
   - track isolation: ptcone40/pt < 0.10 && ptcone40 < 5 GeV (although tightened for our more recent in-approval-update for publication!)
ee-channel:
   - pt 25/20 GeV
   - medium && medium++ && B-layer hit if expected
   - calorimeter isolation: etcone20(corrected for pileup & leakage) < 3 GeV + (Et-20GeV)*0.037
   - track isolation:  ptcone30/Et < 0.10
   - loose IP cuts
eµ-channel:  hbrid of the above...