ExclusiveBsdecays to the charmed mesonsDs+(1968,2317)in the standard model

Abstract

The transition form factors of ${\overline{B}}_{s}^{0}\ensuremath{\rightarrow}{D}_{s}^{+}(2317)$ and ${\overline{B}}_{s}^{0}\ensuremath{\rightarrow}{D}_{s}^{+}(1968)$ at large recoil region are investigated in the light cone sum rules approach, where the heavy quark effective theory is adopted to describe the form factors at small recoil region. With the form factors obtained, we carry out a detailed analysis on both the semileptonic decays ${\overline{B}}_{s}^{0}\ensuremath{\rightarrow}{D}_{s}^{+}(1968,2317)l{\overline{\ensuremath{\nu}}}_{l}$ and nonleptonic decays ${B}_{s}\ensuremath{\rightarrow}{D}_{s}^{+}(1968,2317)M$ with $M$ being a light meson or a charmed meson under the factorization approach. Our results show that the branching fraction of ${\overline{B}}_{s}^{0}\ensuremath{\rightarrow}{D}_{s}^{+}(2317)\ensuremath{\mu}{\overline{\ensuremath{\nu}}}_{\ensuremath{\mu}}$ is around $2.3\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$, which should be detectable with ease at the Tevatron and CERN LHC. It is also found that the branching fractions of ${\overline{B}}_{s}^{0}\ensuremath{\rightarrow}{D}_{s}^{+}(1968)l{\overline{\ensuremath{\nu}}}_{l}$ are almost 1 order larger than those of the corresponding ${B}_{s}^{0}\ensuremath{\rightarrow}{D}_{s}^{+}(2317)l{\overline{\ensuremath{\nu}}}_{l}$ decays. The consistency of predictions for ${B}_{s}\ensuremath{\rightarrow}{D}_{s}^{+}(1968,2317)L$ ($L$ denotes a light meson) in the factorization assumption and ${k}_{T}$ factorization also supports the success of color transparency mechanism in the color allowed decay modes. Most two-charmed meson decays of ${B}_{s}$ mesons possess quite large branching ratios that are accessible in the experiments. These channels are of great importance to explore the hadronic structure of charmed mesons as well as the nonperturbative dynamics of QCD.