Inclusive Decays of B Mesons into D_s and $D_s^{\ast}$ at $O(\alpha_s)$ Including $D_s^{\ast}$ Polarization Effects

Abstract

The dominant contribution to the inclusive decays of $B$ mesons into the charm-strangeness mesons $D_s$ and $D_s^{\ast}$ is expected to be given by the partonic process $b \to c+(D_s^-,D_s^{\ast -})$. We determine the nonperturbative $O(1/m_b^2)$ and the $O(\alpha_s)$ radiative corrections to $b \to c+(D_s^-,D_s^{\ast -})$ and thereby to the inclusive decays $ \bar{B} \to X_c+(D_s^-,D_s^{\ast -})$. The new feature of our calculation is that we separately determine the nonperturbative and the $O(\alpha_s)$ corrections to the longitudinal ($L$) and transverse ($T$) pieces of the spin 1 $D_s^{\ast -}$ meson. The longitudinal/transverse composition of the $D_s^{\ast -}$ can be probed through its two principal decay modes $D_s^{\ast -} \to D_s^- + \gamma$ and $D_s^{\ast -} \to D_s^- + \pi^0$ for which we write down the angular decay distributions.