Supersymmetry search for LHC: generator validation of Pythia and Sherpa

At the LHC the search for Supersymmetry will be one of the prime topics. Our interest is focused on the scenario, suggested by the interpretation of the EGRET excess of diffuse Galactic gamma rays as a signal of dark matter annihilation. In the mSUGRA model this leads to light gaugino mass (≤0.5 TeV) and heavy squarks and sleptons (≥.5 TeV). The prime signatures distinguishing gluino productions from the SM background are jet multiplicity and missing transverse energy. In this talk the background studies based on the NLO parton shower model, as implemented in Pythia and NLO parton shower model combined with QCD second order ME model as implemented in Sherpa, are compared. (orig.)