The purely leptonic and semileptonic decays of $D^{*}_{s}$ meson

Abstract

With the potential prospects of the $D^{*}_{s}$ at high-luminosity heavy-flavor experiments in the future, we investigated the CKM-favored and tree-dominated leptonic $D^{*}_{s}\to\ell\bar{\nu}_{\ell}$ and semileptonic $D^{*}_{s}\to M\ell\bar{\nu}_{\ell}$ ($M=\phi, \eta^{(\prime)}$ and $\ell=e, \mu$) weak decays in the Standard Model (SM). The theoretical predictions and some discussions for the observable quantities including the total width of $D^{*}_{s}$ mesons, the branching fractions of leptonic $D^{*}_{s}\to\ell\bar{\nu}_{\ell}$ and semileptonic $D^{*}_{s}\to M\ell\bar{\nu}_{\ell}$ weak decays, the lepton spin asymmetry and forward-backward asymmetry are presented. Numerically, the weak decays of $D^{*}_{s}\to\ell\bar{\nu}_{\ell}$ and $D^{*}_{s} \to M\ell\bar{\nu}_{\ell}$ have relatively large branching fractions of the order $\mathcal{O}(10^{-5})$ and $\mathcal{O}(10^{-7})$ respectively, which are expected to be observed in future experiments.