Semi-leptonic decays of $B^\ast$, $B_s^\ast$, and $B_c^\ast$ with the Bethe-Salpeter method

TL;DR

This paper calculates the semileptonic decay properties of excited B mesons using the Bethe-Salpeter method, providing estimates for decay widths and branching ratios relevant for experimental detection.

Contribution

It applies the Bethe-Salpeter approach with instantaneous approximation to compute decay widths and branching ratios of $B^*$, $B_s^*$, and $B_c^*$ mesons, which is a novel theoretical analysis.

Findings

Largest partial width around 10^{-14} GeV.

Branching ratios for specific decays range from 10^{-8} to 10^{-6}.

Identifies promising channels for experimental observation.

Abstract

In this paper we study the semileptonic decays of $B^\ast$, $B_s^\ast$, and $B_c^\ast$ by using the Bethe-Salpeter method with instantaneous approximation. Both the $V\to Pl^-\bar\nu_l$ and $V\to Vl^-\bar\nu_l$ cases are considered. The largest partial width of these channels is of the order of $10^{-14}$ GeV. The branching ratios of these semileptonic decays are also estimated by using the partial width of the one photon decay channel to approximate the total width. For $B^{\ast-}\to D^{(\ast)0}e^-\bar\nu_e$ and $B_s^{\ast0}\to D_s^{(\ast)+}e^-\bar\nu_e$, the branching ratios are of the order of $10^{-8}$ and $10^{-7}$, respectively. For $B_c^{\ast-}$, the $J/\psi e^-\bar\nu_e$ and $B_s^{\ast0}e^-\bar\nu_e$ channels have the largest branching ratio, which is of the order of $10^{-6}$.