Paper detail

Is it possible to explain the muon and electron $g-2$ in a $Z^{\prime}$ model?

In order to address this question, we consider a simple renormalisable and gauge invariant model in which the $Z'$ only has couplings to the electron and muon and their associated neutrinos, arising from mixing with a heavy vector-like fourth family of leptons. Within this model we discuss the contributions to the electron and muon anomalous magnetic moments from $Z'$ exchange, subject to the constraints from $μ\rightarrow e γ$ and neutrino trident production. Using analytic and numerical arguments, we find that such a $Z'$ model can account for either the electron or the muon $g-2$ anomalies, but not both, while remaining consistent with the experimental constraints from $μ\rightarrow e γ$ and neutrino trident production.