Supersymmetry searches in ATLAS at the LHC

This Thesis presents two different SUSY searches in strong production using ATLAS data. The first analysis presented, searches for Supersymmetry in final states containing seven or more jets (multijets), one isolated lepton (electron or muon) and missing transverse energy (ETmiss). The search is based on data from the full 2011 data-taking period, corresponding to an integrated luminosity of 4.7/fb and a centre-of-mass energy sqrt(s) = 7 TeV. The results of this analysis are interpreted in the context of a bilinear R-parity violating (bRPV) mSUGRA/CMSSM model. The second analysis is a search for Supersymmetry in final states characterised by a Z boson that decays to an electron or a muon pair, large ETmiss and jets. The proton-proton collision data used in this search were collected at a centre-of-mass energy sqrt(s) = 8 TeV by the ATLAS detector at the LHC and correspond to an integrated luminosity of 20.3/fb. The results are interpreted in the context of a GGM supersymmetric model.