Search for squarks and gluinos in final states with jets and missing transverse momentum with the ATLAS detector at LHC

A search for squarks and gluinos in final states containing jets, missing transverse momentum and no high-momentum electrons or muons is presented. The studies presented in this thesis extend the sensitivity of the previous analysis by including new selections and by substantially improving the background determination and the systematic uncertainties. No excess above the Standard Model background expectation is observed in both 7 and 8 TeV data collected by the ATLAS experiment. Limits are set on the squark and gluino masses in a number of SUSY scenarios in the MSSM model. These limits considerably extend the region of supersymmetric parameter space excluded by previous measurements with the ATLAS detector.