Trilepton production at the CERN LHC: SUSY Signals and Standard Model Backgrounds

Abstract

Events with isolated leptons and missing energy in the final state are known to be signatures of new physics phenomena at high energy collider physics facilities. Standard model (SM) sources of isolated trilepton final states include gauge boson pair production such as W Z and Wg , and tproduction. Symbol g represents a virtual photon. Our new contribution is the demonstration that bottom and charm meson decays, b! lX and c! lX, produce isolated lepton events that can overwhelm the effects of other processes. We compute contributions from a wide range of SM heavy flavor processes including bZ=g , cZ=g , b¯ bZ=g , c ¯ cZ=g . We also include contributions from processes in which a W is produced in association with one or more heavy flavors such as tW , b¯ bW , c ¯ cW . In all these cases, one or more of the final observed isolated leptons comes from a heavy flavor decay. We propose new cuts to control the heavy flavor backgrounds in the specific case of chargino plus neutralino pair production in supersymmetric models. PACS: 13.85.Qk, 13.85.Rm, 12.60.Jv