Measurement of B→Ds(*)+D*(*) branching fractions

Le résumé fourni par la source

This article describes improved measurements by CLEO of the ${B}^{0}\ensuremath{\rightarrow}{D}_{s}^{+}{D}^{*\ensuremath{-}}$ and ${B}^{0}\ensuremath{\rightarrow}{D}_{s}^{*+}{D}^{*\ensuremath{-}}$ branching fractions, and first evidence for the decay ${B}^{+}\ensuremath{\rightarrow}{D}_{s}^{(*)+}{D}^{**0},$ where ${D}^{**0}$ represents the sum of the ${D}_{1}{(2420)}^{0},$ ${D}_{2}^{*}{(2460)}^{0},$ and ${D}_{1}{(j=1/2)}^{0}L=1$ charm meson states. Also reported is the first measurement of the ${D}_{s}^{*+}$ polarization in the decay ${B}^{0}\ensuremath{\rightarrow}{D}_{s}^{*+}{D}^{*\ensuremath{-}}.$ A partial reconstruction technique, employing only the fully reconstructed ${D}_{s}^{+}$ and slow pion ${\ensuremath{\pi}}_{s}^{\ensuremath{-}}$ from the ${D}^{*\ensuremath{-}}\ensuremath{\rightarrow}{D}^{0}{\ensuremath{\pi}}_{s}^{\ensuremath{-}}$ decay, enhances sensitivity. The observed branching fractions are $\mathcal{B}{(B}^{0}\ensuremath{\rightarrow}{D}_{s}^{+}{D}^{*\ensuremath{-}})=(1.10\ifmmode\pm\else\textpm\fi{}0.18\ifmmode\pm\else\textpm\fi{}0.10\ifmmode\pm\else\textpm\fi{}0.28)%,$ $\mathcal{B}{(B}^{0}\ensuremath{\rightarrow}{D}_{s}^{*+}{D}^{*\ensuremath{-}})=(1.82\ifmmode\pm\else\textpm\fi{}0.37\ifmmode\pm\else\textpm\fi{}0.24\ifmmode\pm\else\textpm\fi{}0.46)%$, and $\mathcal{B}{(B}^{+}\ensuremath{\rightarrow}{D}_{s}^{(*)+}{D}^{**0})=(2.73\ifmmode\pm\else\textpm\fi{}0.78\ifmmode\pm\else\textpm\fi{}0.48\ifmmode\pm\else\textpm\fi{}0.68)%,$ where the first error is statistical, the second systematic, and the third is the uncertainty in the ${D}_{s}^{+}\ensuremath{\rightarrow}\ensuremath{\varphi}{\ensuremath{\pi}}^{+}$ branching fraction. The measured ${D}_{s}^{*+}$ longitudinal polarization, ${\ensuremath{\Gamma}}_{L}/\ensuremath{\Gamma}=(50.6\ifmmode\pm\else\textpm\fi{}13.9\ifmmode\pm\else\textpm\fi{}3.6)%,$ is consistent with the factorization prediction of 54%.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.