Family non-universal U(1)′ model with minimal number of exotics

Abstract

We have studied phenomenological implications of several family non-universal U(1)′ sub-models in the U(1)′-extended Minimal Supersymmetric Standard Model (UMSSM) possessing an extra down quark type exotic field. In doing this, we have started by enforcing anomaly cancellation criteria to generate a number of solutions in which the extra U(1)′ charges of the particles are treated as free parameters. We have then imposed existing bounds coming from colliders and astrophysical observations on the assumed sub-models and observed that current limits dictate certain charge orientations, for instance, QHu∼QHd is preferred in general and the charge of the singlet QS cannot be very small (|QS|> 0.4) even if any of the charges is allowed to take any value within the [−1,1] range. We have finally studied the potential impact of such non-universal charges on Z′ mediated processes and made predictions for existing and future experiments. It has turned out that UMSSMs with or without the presence of light exotic quarks can yield distinguishable signatures if non-universal charges are realised in the leptonic sector of such models.