Measurement of the branching fractions for B−→D(*)+π−ℓ−ν¯ℓ and B0¯→D(*)0π+ℓ−ν¯ℓ

Le résumé fourni par la source

We report on a measurement of the branching fractions for ${B}^{\ensuremath{-}}\ensuremath{\rightarrow}{D}^{(*)+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\ell}}^{\ensuremath{-}}{\overline{\ensuremath{\nu}}}_{\ensuremath{\ell}}$ and $\overline{{B}^{0}}\ensuremath{\rightarrow}{D}^{(*)0}{\ensuremath{\pi}}^{+}{\ensuremath{\ell}}^{\ensuremath{-}}{\overline{\ensuremath{\nu}}}_{\ensuremath{\ell}}$ with $275\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $B\overline{B}$ events collected at the $\ensuremath{\Upsilon}(4S)$ resonance with the Belle detector at KEKB. Events are tagged by fully reconstructing one of the $B$ mesons in hadronic modes. We obtain $\mathcal{B}({B}^{\ensuremath{-}}\ensuremath{\rightarrow}{D}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\ell}}^{\ensuremath{-}}{\overline{\ensuremath{\nu}}}_{\ensuremath{\ell}})=(0.54\ifmmode\pm\else\textpm\fi{}0.07(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.07(\mathrm{syst})\ifmmode\pm\else\textpm\fi{}0.06(\mathrm{BR}))\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}2}$, $\mathcal{B}({B}^{\ensuremath{-}}\ensuremath{\rightarrow}{D}^{*+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\ell}}^{\ensuremath{-}}{\overline{\ensuremath{\nu}}}_{\ensuremath{\ell}})=(0.67\ifmmode\pm\else\textpm\fi{}0.11(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.09(\mathrm{syst})\ifmmode\pm\else\textpm\fi{}0.03(\mathrm{BR}))\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}2}$, $\mathcal{B}(\overline{{B}^{0}}\ensuremath{\rightarrow}{D}^{0}{\ensuremath{\pi}}^{+}{\ensuremath{\ell}}^{\ensuremath{-}}{\overline{\ensuremath{\nu}}}_{\ensuremath{\ell}})=(0.33\ifmmode\pm\else\textpm\fi{}0.06(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.06(\mathrm{syst})\ifmmode\pm\else\textpm\fi{}0.03(\mathrm{BR}))\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}2}$, $\mathcal{B}(\overline{{B}^{0}}\ensuremath{\rightarrow}{D}^{*0}{\ensuremath{\pi}}^{+}{\ensuremath{\ell}}^{\ensuremath{-}}{\overline{\ensuremath{\nu}}}_{\ensuremath{\ell}})=(0.65\ifmmode\pm\else\textpm\fi{}0.12(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.08(\mathrm{syst})\ifmmode\pm\else\textpm\fi{}0.05(\mathrm{BR}))\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}2}$, where the third error comes from the error on $\overline{B}\ensuremath{\rightarrow}{D}^{(*)}{\ensuremath{\ell}}^{\ensuremath{-}}{\overline{\ensuremath{\nu}}}_{\ensuremath{\ell}}$ decays. Contributions from $\overline{{B}^{0}}\ensuremath{\rightarrow}{D}^{*+}{\ensuremath{\ell}}^{\ensuremath{-}}{\overline{\ensuremath{\nu}}}_{\ensuremath{\ell}}$ decays are excluded in the measurement of $\overline{{B}^{0}}\ensuremath{\rightarrow}{D}^{0}{\ensuremath{\pi}}^{+}{\ensuremath{\ell}}^{\ensuremath{-}}{\overline{\ensuremath{\nu}}}_{\ensuremath{\ell}}$.

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