Family Non-Universal U(1)$^\prime$ Model with Minimal Number of Exotics

TL;DR

This paper explores family non-universal U(1)' models within the UMSSM framework, analyzing anomaly cancellation, experimental constraints, and potential collider signatures, especially focusing on leptonic sector distinctions due to non-universal charges.

Contribution

It introduces minimal exotic content models with non-universal U(1)' charges, analyzing their phenomenology and experimental implications within the UMSSM.

Findings

Current collider and astrophysical bounds restrict charge assignments.

Non-universal charges can lead to distinguishable Z' signatures in leptonic processes.

Models without light exotics still produce observable collider signatures.

Abstract

We have studied phenomenological implications of several family non-universal U(1)$^\prime$ sub-models in the U(1)$^\prime$-extended Minimal Supersysmmetric Standard Model (UMSSM) possesing 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)$^\prime$ 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, $Q_{H_u}\sim Q_{H_d}$ is preferred in general and the charge of the singlet $Q_S$ cannot be very small ($|Q_S|>$ 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 distinguisable signatures if non-universal charges are realised in the leptonic sector of such models.