Implication of family non-universal Z′ model to rare exclusive $b \to s(l\bar l,\nu\bar\nu)$ transitions

• Published in: Progress of theoretical and experimental physics Vol. 2019; no. 3
• Main Authors: Maji, P, Nayek, P, Sahoo, S
• Format: Journal Article
• Language: English
• Published: Oxford University Press 01.03.2019
• Subjects: B56; B57; B40; B51
• ISSN: 2050-3911; 2050-3911
• DOI: 10.1093/ptep/ptz010

Abstract We have investigated $B \to (K,K^\ast)(l\bar l,\nu \bar\nu)$ 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^\ast} $ 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 $R_{K^\ast}$ 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 $R_{K^\ast}$ could be achieved in a non-universal $Z^\prime$ model considering the new physics couplings to the muon sector only.