Heavy neutral gauge bosons at the LHC in an extended MSSM

Searching for heavy neutral gauge bosons Z′, predicted in extensions of the Standard Model based on a U(1)′ gauge symmetry, is one of the challenging objectives of the experiments carried out at the Large Hadron Collider. In this paper, we study Z′ phenomenology at hadron colliders according to several U(1)′-based models and in the Sequential Standard Model. In particular, possible Z′ decays into supersymmetric particles are included, in addition to the Standard Model modes so far investigated. We point out the impact of the U(1)′ group on the MSSM spectrum and, for a better understanding, we consider a few benchmarks points in the parameter space. We account for the D-term contribution, due to the breaking of U(1)′, to slepton and squark masses and investigate its effect on Z′ decays into sfermions. Results on branching ratios and cross sections are presented, as a function of the MSSM and U(1)′ parameters, which are varied within suitable ranges. We pay special attention to final states with leptons and missing energy and make predictions on the number of events with sparticle production in Z′ decays, for a few values of integrated luminosity and centre-of-mass energy of the LHC.