Impact of a non-universal $Z^\prime$ on the $B\to K^{(*)}l^+l^-$ and $B \to K^{(*)}\nu\bar{\nu}$ processes

Abstract

We perform a study of the new physics effects in semileptonic FCNC processes within a low-energy approximation of the anomaly-free supersymmetic extension of the SM with additional $Z'$ vector field. The key feature of the model is the non-diagonal structure of $Z'$ couplings to fermions, which is parameterized by few new-physics parameters in addition to well-known mixing matrices for quarks and leptons in the SM. We not only consider CP-conserving scenarios with real parameters, but also account for possible CP violation due to new physical weak phases. We analyse the dependence of the $b\to s$ observables on the parameters together with correlations between the observables predicted in the model. Special attention is paid to possible enhancement of $B \to K^{(*)} \nu\bar{\nu}$ rates and to CP-odd angular observables in $B \to K^* ll$ decays.