Probing the electroweak sector of the μνSSM at the LHC

In this thesis we discuss the phenomenological aspects of a SUSY model, the so-called called μνSSM, at the LHC. Besides the good common properties of the SUSY models, the μνSSM can provide a solution of the μ-problem of the Minimal Supersymmetric Stan-dard Model (MSSM) and simultaneously explain the origin of the measured properties of neutrinos. In addition, the Gravitino in the μνSSM is a good DM candidate also.

Search for SUSY at accelerators has been focused mainly on signals with MET inspired in RPC models, such as the minimal supersymmetric standard model (MSSM) where significant bounds on particle masses have been obtained. Qualitatively similar results have also been obtained in the analysis of simplified RPV scenarios with trilinear lepton- or baryon-number violating terms, assuming a single channel available for the decay of the LSP. The objective of this thesis is to make an exhaustive exploration of interesting signals within the μνSSM framework. In particular, we focus on the EW sector of the model, which in principle can be explored with a certain ease in a hadron collider, and identify the signatures that can appear in the production of EW superpartners at the LHC.

In the first part we analyze the posibilites to detect the left-handed neutrino superpartner, the left sneutrino, when it is the LSP thorugh propmt searches at the LHC. In the second part we use some of the current ATLAS searches for long lived particles to constrain the parameter space of the model, when the left sneutrino is the LSP and decays at significant distance of the interaction point, producing displaced vertices. In the last part we utilize the ATLAS searches for EW production of SUSY particles in compressed scenarios, to obtain limits on the sneutrino mass, when the LSP is a bino-like neutralino and the sneutrino is the NLSP