Búsqueda de Supersimetría en eventos con un fotón, jets y energía faltante con el detector ATLAS

Supersymmetry (SUSY) is one of the most motivated theories for physics beyond the Standard Model, giving a framework to the unification of the particle physics and gravity, which is governed by the Plank energy scale. As none of the predicted supersymmetric particles has been discovered, SUSY must be a broken symmetry in nature. SUSY phenomenology is hardly determined by the SUSY breaking mechanism. GGM models in which the SUSY breaking is mediated by the usual gauge fields of the Standard Model provide a suitable scenario for SUSY searches at the LHC, with very characteristic mass spectrum and decays. This thesis presents the first search of new physics with one energetic photon, jets and high missing energy in the final state in proton-proton collisions at a centre-of mass energy of 8 TeV. The analysis was realized with all the data collected by the ATLAS detector during 2012, corresponding to a total integrated luminosity of 20.3 fb$^{-1}$. No excess over the Standard Model predictions was observed, so an upper limit in the number of new physics events was established at 95 % CL for this final state. Additionally, the results were also interpreted in the context of a GGM SUSY model considering a bino-higgsino neutralino NLSP admixture, excluding the production of gluinos with masses up to 1.25 TeV, giving the most strict limits at the moment.