Observation of the D1(2420)→Dπ+π− Decays

Le résumé fourni par la source

We report on the first observation of ${D}_{1}^{0}(2420)\ensuremath{\rightarrow}{D}^{0}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$ and ${D}_{1}^{+}(2420)\ensuremath{\rightarrow}{D}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$ decays (where the contribution from the dominant known ${D}_{1}\ensuremath{\rightarrow}{D}^{*}\ensuremath{\pi}$ decay mode is excluded) in the ${B}^{\ensuremath{-}}\ensuremath{\rightarrow}{D}_{1}^{0}{\ensuremath{\pi}}^{\ensuremath{-}}$ and ${\overline{B}}^{0}\ensuremath{\rightarrow}{D}_{1}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ decays, respectively. The observation is based on $15.2\ifmmode\times\else\texttimes\fi{}{10}^{7}$ $B\overline{B}$ events collected with the Belle detector at the KEKB collider. We also set 90% confidence level upper limits for the branching fractions of the four following decays: ${B}^{\ensuremath{-}}\ensuremath{\rightarrow}{D}_{1}^{0}{\ensuremath{\pi}}^{\ensuremath{-}}$, ${D}_{1}^{0}\ensuremath{\rightarrow}{D}^{*0}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$, ${\overline{B}}^{0}\ensuremath{\rightarrow}{D}_{1}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$, ${D}_{1}^{+}\ensuremath{\rightarrow}{D}^{*+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$, ${B}^{\ensuremath{-}}\ensuremath{\rightarrow}{D}_{2}^{*0}(2460){\ensuremath{\pi}}^{\ensuremath{-}}$, ${D}_{2}^{*0}\ensuremath{\rightarrow}{D}^{*0}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$, ${\overline{B}}^{0}\ensuremath{\rightarrow}{D}_{2}^{*+}(2460){\ensuremath{\pi}}^{\ensuremath{-}}$, ${D}_{2}^{*+}\ensuremath{\rightarrow}{D}^{*+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$.

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