The MSSM has undoubtedly been a successful framework in terms of
suggesting solutions to the unresolved shortcomings of the Standard Model
such as Dark Matter, the Gauge hierarchy problem etc. However, the lack of
evidence for Supersymmetry at the LHC motivates us to investigate extensions
of the MSSM basic gauge group structure, with the hope of finding answers to
these questions. For this reason, we have studied a simple U(1)’ extension
of the MSSM group structure which can arise within the Grand Unified
framework. We investigate scenarios in which either the right-handed
sneutrino or the lightest neutralino are viable dark matter candidates and
we explore the parameter space of different supersymmetric realisations
featuring an extra U(1)'. On the side of LHC phenomenology, searching for
heavy Z' vector bosons predicted in such models is a challenging objective.
The ATLAS and CMS collaborations have looked for such Z’ bosons assuming
that they can only decay into Standard Model channels, and have placed
corresponding exclusion limits by considering dilepton, dijet and, to a
smaller extent, top-antitop final states. Alongside with dark matter, we
also explore possible loopholes in these Z’ searches by studying
supersymmetric as well as leptophobic scenarios and we proposed a possible
way to probe leptophobic Z’ via supersymmetric final states.
