Search for B+→e+νe and B+→μ+νμ decays using hadronic tagging

Le résumé fourni par la source

We present a search for the rare leptonic decays ${B}^{+}\ensuremath{\rightarrow}{e}^{+}{\ensuremath{\nu}}_{e}$ and ${B}^{+}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\nu}}_{\ensuremath{\mu}}$, using the full $\mathrm{\ensuremath{\Upsilon}}(4S)$ data sample of $772\ifmmode\times\else\texttimes\fi{}1{0}^{6}$ $B\overline{B}$ pairs collected with the Belle detector at the KEKB asymmetric-energy ${e}^{+}{e}^{\ensuremath{-}}$ collider. One of the $B$ mesons from the $\mathrm{\ensuremath{\Upsilon}}(4S)\ensuremath{\rightarrow}B\overline{B}$ decay is fully reconstructed in a hadronic mode, while the recoiling side is analyzed for the signal decay. We find no evidence of a signal in any of the decay modes. Upper limits of the corresponding branching fractions are determined as $\mathcal{B}({B}^{+}\ensuremath{\rightarrow}{e}^{+}{\ensuremath{\nu}}_{e})<3.5\ifmmode\times\else\texttimes\fi{}1{0}^{\ensuremath{-}6}$ and $\mathcal{B}({B}^{+}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\nu}}_{\ensuremath{\mu}})<2.7\ifmmode\times\else\texttimes\fi{}1{0}^{\ensuremath{-}6}$ at 90% confidence level.

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