Study of the rare decays B_(s,d)^* arrow l^+ l^- in Z' model

The rare decays $B_{(s,d)}^*\to l^+ l^-$ are important to probe the flavour sector of the standard model and to search new physics beyond the SM. Unlike pseudoscalar B meson, the leptonic decays of vector $ B_(s,d)^*$ mesons are not chirally supressed which compensates for their short lifetimes, and results significant branching ratios. In this paper, we estimate the branching ratios of $B_{(s,d)}^*\to l^+ l^-$ $(l=e,\mu)$ rare decays in Z' model which is an extension of the SM with an extra U(1)' gauge symmetry. We find that the branching ratios are increased from their corresponding standard model values and vary with the mass of $Z'$ boson. Lower is the mass of $Z'$ boson, higher is the branching ratio.