Evidence for the Suppressed Decay B−→DK− , D→K+π−

Le résumé fourni par la source

The suppressed decay chain ${B}^{\ensuremath{-}}\ensuremath{\rightarrow}D{K}^{\ensuremath{-}}$, $D\ensuremath{\rightarrow}{K}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$, where $D$ indicates a ${\overline{D}}^{0}$ or ${D}^{0}$ state, provides important information on the $CP$-violating angle ${\ensuremath{\phi}}_{3}$. We measure the ratio ${\mathcal{R}}_{DK}$ of the decay rates to the favored mode ${B}^{\ensuremath{-}}\ensuremath{\rightarrow}D{K}^{\ensuremath{-}}$, $D\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$ to be ${\mathcal{R}}_{DK}=[{1.63}_{\ensuremath{-}0.41}^{+0.44}(\mathrm{stat}{)}_{\ensuremath{-}0.13}^{+0.07}(\mathrm{syst})]\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}2}$, which indicates the first evidence of the signal with a significance of $4.1\ensuremath{\sigma}$. We also measure the asymmetry ${\mathcal{A}}_{DK}$ between the charge-conjugate decays to be ${\mathcal{A}}_{DK}=\ensuremath{-}{0.39}_{\ensuremath{-}0.28}^{+0.26}(\mathrm{stat}{)}_{\ensuremath{-}0.03}^{+0.04}(\mathrm{syst})$. The results are based on the full $772\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $B\overline{B}$ pair data sample collected at the $\ensuremath{\Upsilon}(4S)$ resonance with the Belle detector.

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