Reappraisal of the minimal flavoured $Z^{\prime }$ scenario

Abstract

Recent results from the intensity frontier indicate the tantalizing possibility of violation in lepton flavour universality. In light of this we revisit the minimal phenomenological $Z^{\prime }$ model taking in account both vectorial and axial-vectorial flavour violating couplings to the charged leptons. We make a systematic study to identify the minimal framework that can simultaneously explain the recent results on anomalous magnetic moment of muon and electron while remaining in consonance with $R_{K^{(\ast )}}$, $B_s^0-\overline{B_s^0}$ mixing and angular observables in the $B^{+}\to K^{+\ast }\hat{I}{¼}^{+}\hat{I}{¼}^{-}$ channel reported by the LHCb collaboration. We demonstrate that the neutrino trident data imply a further ${\mathrm{SU}(2)}_L$ violation in the leptonic couplings of the exotic $Z^{\prime }$.

35 pages, 8 captioned figures and matches published version