A Search for Supersymmetry with Same–Sign Tau and Lepton Final States at the CMS Experiment

A search for Supersymmetry signals with Same–Sign Dileptons in the final state at the Large Hadron Collider is presented. The results are based on 976 pb−1 of pp collision data recorded by the Compact Muon Solenoid experiment at 7 TeV centre of mass energy. The analysis strategy for channels including a hadronically decaying τ (eτ,μτ,ττ) is discussed in detail. The numbers of observed events are compatible with the expectation from Standard Model processes in all the considered channels with a total of 2.9 ± 1.7 predicted and 3 observed. An Upper Limit of total observed events from New Physics is extracted at the 95% Confidence Level and is equal to 5.8. The results are interpreted in the Constrained Minimal Supersymmetric Standard Model and a simplified Supersymmetry model favouring τ channels characterised by pp → 􏰍g􏰍g with Br(􏰍g → χ􏰍±qq′) = 100% and Br(χ􏰍+ → χ􏰍0τ+ν ) = 100%. 1 11τ A lower limit of 400 GeV on the gluino mass is set in the simplified model for neutralino masses up to 350 GeV, with the exception of the region around m􏰍g ≈ mLSP . This exclusion extends to gluino masses of up to 620 GeV for neutralino masses of less than 100 GeV.