$D^*_{(s)}\to P$ form factors and their applications to semi-leptonic and non-leptonic weak decays

Abstract

Similar to other heavy flavor mesons, the weak decays of $D^*_{(s)}$ mesons can provide a platform to verify the standard model, explore new physics, and understand the mechanisms of weak interactions. At present, the theoretical and experimental studies on $D^*_{(s)}$ mesons are relatively limited. In addition to the dominant electromagnetic decays, the $D^*_{(s)}$ weak decays should be feasible to explore the $D^*_{(s)}$ mesons. In this study, we used the covariant light-front quark model to study the form factors of the transitions $D^*_{(s)}\to \pi, K, \eta_{q,s}$, then calculated the branching ratios of the semi-leptonic decays $D^*_{(s)}\to P\ell^{+}\nu_{\ell}$ and the non-leptonic decays $D^*_{(s)}\to PP, PV$ with $P=\pi, K, \eta^{(\prime)}, V=\rho, K^*, \phi$ and $\ell=e, \mu$. The channels $D_{s}^{*+}\to\eta \ell^{+}\nu_{\ell}$ and $D^{*+}_{s}\to \eta\rho^{+}$ possess the largest branching ratios, which can reach an order of $10^{-6}$ among these decays, and are most likely to be accessible in experiments at future high-luminosity colliders. Furthermore, we predict and discuss the longitudinal polarization fraction $f_{L}$ and the forward-backward asymmetry $A_{FB}$ for the considered semi-leptonic $D^*_{(s)}$ decays.