Study of the rare decays $B_{s,d}^{\ast }\to {\mu }^{+}{\mu }^{-}$

We study rare leptonic decays of vector $B$ mesons in the scalar leptoquark and family non-universal $Z^{\mathrm{\prime }}$ models. We constrain these new couplings by using the measured branching fractions of $B_{s,d}\to {\mu }^{+}{\mu }^{-}$ processes and the existing $B_{s,d}^0-{\bar{B}}_{s,d}^0$ mixing data. We estimate the branching fractions of $B_{s,d}^{\ast }\to {\mu }^{+}{\mu }^{-}$ in both the models, which are found to be reasonably enhanced from their corresponding standard model values and within the reach of Run 2-3 of LHC.