Lepton Polarization Asymmetry in B*s,d → μ+ μ− with new Z′ Couplings

Abstract

We study the effect of non-universal Z′ boson on the rare leponic decay modes of \( {B}_s^{\ast } \) mesons, mediated by b → sll quark transition. Rare B decays are sensitive to various new physics operators. As B mesons are composite particles, such decay modes of the excited states are ideal for probing new physics beyond the standard model. We have constrained our model parameters from \( {B}_{s,d}-{\overline{B}}_{s,d} \) mixing data to predict the lepton polarization asymmetry of \( {B}_{s,d}^{\ast}\to {\mu}^{+}{\mu}^{-} \) channel. It is found that this asymmetry deviates from its SM prediction along with the Z′ effect.