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

TL;DR

This paper estimates the branching ratios of rare vector B meson decays into lepton pairs within a Z' model, showing enhancements over the Standard Model predictions that depend on the Z' boson mass.

Contribution

It provides the first estimation of $B_{(s,d)}^* o l^+ l^-$ decay rates in a Z' extension of the Standard Model, highlighting the impact of Z' mass on these branching ratios.

Findings

Branching ratios are increased compared to the Standard Model.

Lower Z' mass leads to higher branching ratios.

Results suggest potential signals for new physics in rare B* decays.

Abstract

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.