Study of $B\to K^{(\ast )}{\ell }^{+}{\ell }^{-}$ Decays in the Family Non-universal $Z^{\prime }$ Models

Abstract

In a combined investigation of the $B\to K^{(\ast )}{\ell }^{+}{\ell }^{-}$ decays, constraints on the related couplings in family non-universal $Z^{\prime }$ models are derived. We find that within the allowed parameter space, the recently observed forward-backward asymmetry in the $B\to K^{\ast }{\ell }^{+}{\ell }^{-}$ decay can be explained, by flipping the signs of the Wilson coefficients $C_9^{\mathrm{eff}}$ and $C_{10}$. With the obtained constraints, we also calculate the branching ratio of the $B_s\to {\mu }^{+}{\mu }^{-}$ decay. The upper bound of our prediction is near the upper bound given by CDF Collaboration recently.

Comments: 19 pages, 4 figures, some errors corrected; Journal version