Selected decays of $B_{s}$ meson in covariant confined quark model

Abstract

We present a study of various $B_{s}$ meson decays, including hadronic and semileptonic final states with different spins and diagram topologies. The covariant confined quark model is employed to describe hadronic effects, and our analysis serves as a broad test of the current understanding of the underlying dynamics within the Standard Model. The level of agreement with experimental data varies across channels: it is good for the semileptonic decays $B_{s}^{0}\to D_{s}^{-}\mu^{+}\nu_{\mu}$ and $B_{s}^{0}\to K^{-}\mu^{+}\nu_{\mu}$; acceptable for the hadronic modes $B_{s}^{0}\to D_{s}^{-}D^{+}$ and $B_{s}^{0}\to K^{-}\pi^{+}$; marginal for $B_{s}^{0}\to D_{s}^{-}\pi^{+}$, $B_{s}^{0}\to D_{s}^{-}\rho^{+}$, and $B_{s}^{0}\to\phi\,J/\psi$; and significantly discrepant for $B_{s}^{0}\to\phi\,\overline{D^{0}}$ and $B_{s}^{0}\to\phi\,\eta_{c}$. We argue that the observed inconsistencies may arise from the breakdown of naive factorization and unaccounted long-distance effects. In particular, the channels $B_{s}^{0}\to D_{s}^{-}\pi^{+}$ and $B_{s}^{0}\to D_{s}^{-}\rho^{+}$ are theoretically among the cleanest nonleptonic decays, yet they exhibit persistent discrepancies also reported by other theoretical groups.