Local anomalies in Z’ models

In this talk I will follow the work presented in arXiv:1912.10022 in which we consider local (or perturbative) gauge anomalies in models featuring an extra Z′ boson compared to the Standard Model (SM), along with n SM-singlet fermions. Assuming that the gauge group is compact, we give a general solution to the anomaly cancellation conditions (ACCs) for the ACCs that involve only SM fermions and we examine whether a corresponding solution exists for the remaining ACCs. We argue that this should be adequate for the purposes of phenomenology, at least for the time being. We show that a solution to the remaining ACCs always exists for n≥5 in the family non-universal case or n≥3 in the family-universal case. In the special case where only a single family carries non-vanishing charges, we find a general solution to all ACCs, for any value of n.