Implication of family non-universal Z′ model to rare exclusive |$b o s(lar l,uaru)$| transitions

摘要

We have investigated |$B o (K,K^st)(lar l,u aru)$| decay channels and predicted some form-factor-dependent observables (e.g. branching ratio, forward–backward asymmetry, and lepton polarization asymmetry) considering a new physics contribution from the non-universal |$Z^prime$| model. We have found that there is an appreciable difference between the standard model and |$Z^prime$| model predictions. Recently, the lepton flavor non-universality parameters |$R_K$| and |$R_{K^st} $| have been measured by the LHCb Collaboration and found to be different from their standard model predictions. These deviations provide a hint of flavor non-universality in the lepton sector and motivate our research to look for new physics beyond the standard model. The |$R_{K}$| and |$R_{K^st}$| anomalies may be due to new physics in either the electron or the muon sector, or both. In our work, we have shown that the experimental results for |$R_K$| and |$R_{K^st}$| could be achieved in a non-universal |$Z^prime$| model considering the new physics couplings to the muon sector only.