Measurement of the B+→ωl+ν and B+→ηl+ν branching fractions

Le résumé fourni par la source

We present a study of the charmless semileptonic $B$-meson decays ${B}^{+}\ensuremath{\rightarrow}\ensuremath{\omega}{\ensuremath{\ell}}^{+}\ensuremath{\nu}$ and ${B}^{+}\ensuremath{\rightarrow}\ensuremath{\eta}{\ensuremath{\ell}}^{+}\ensuremath{\nu}$. The analysis is based on $3.83\ifmmode\times\else\texttimes\fi{}{10}^{8}$ $B\overline{B}$ pairs recorded at the $\ensuremath{\Upsilon}(4S)$ resonance with the BABAR detector. The $\ensuremath{\omega}$ mesons are reconstructed in the channel $\ensuremath{\omega}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{0}$ and the $\ensuremath{\eta}$ mesons in the channels $\ensuremath{\eta}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{0}$ and $\ensuremath{\eta}\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\gamma}$. We measure the branching fractions $\mathcal{B}({B}^{+}\ensuremath{\rightarrow}\ensuremath{\omega}{\ensuremath{\ell}}^{+}\ensuremath{\nu})=(1.14\ifmmode\pm\else\textpm\fi{}{0.16}_{\mathrm{stat}}\ifmmode\pm\else\textpm\fi{}{0.08}_{\mathrm{syst}})\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ and $\mathcal{B}({B}^{+}\ensuremath{\rightarrow}\ensuremath{\eta}{\ensuremath{\ell}}^{+}\ensuremath{\nu})=(0.31\ifmmode\pm\else\textpm\fi{}{0.06}_{\mathrm{stat}}\ifmmode\pm\else\textpm\fi{}{0.08}_{\mathrm{syst}})\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$.

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