Search for supersymmetry in events with a single lepton, jets and missing transverse energy with the CMS detector at LHC

This thesis presents searches for supersymmetry in the single-lepton final state, in proton-protoncollisions at center of mass energies of 7 and 8 TeV, recorded by the CMS experiment at the LHC(CERN). The searches are motivated by supersymmetric models involving strong-production processes leading to large cascades of supersymetric particles. The single-lepton signature, accompanied/with multiple jets and E T , provides a clean signature in the hadronic environment of the LHC, whilepreserves large branching fraction for most of the supersymmetric models. No statistically significant deviations from the yields expected by the standard model are observed. Therefore, the resultsare interpreted in the context of various supersymmetric models with a pair production of gluinos,tightening the current limits on the mass of the gluino and the neutralino.