First Observation of CP Violation in B¯0→DCP(*)h0 Decays by a Combined Time-Dependent Analysis ofBABARand Belle Data

Le résumé fourni par la source

We report a measurement of the time-dependent $CP$ asymmetry of ${\overline{B}}^{0}\ensuremath{\rightarrow}{D}_{CP}^{(*)}{h}^{0}$ decays, where the light neutral hadron ${h}^{0}$ is a ${\ensuremath{\pi}}^{0}$, $\ensuremath{\eta}$, or $\ensuremath{\omega}$ meson, and the neutral $D$ meson is reconstructed in the $CP$ eigenstates ${K}^{+}{K}^{\ensuremath{-}}$, ${K}_{S}^{0}{\ensuremath{\pi}}^{0}$, or ${K}_{S}^{0}\ensuremath{\omega}$. The measurement is performed combining the final data samples collected at the $\mathrm{\ensuremath{\Upsilon}}(4S)$ resonance by the BABAR and Belle experiments at the asymmetric-energy $B$ factories PEP-II at SLAC and KEKB at KEK, respectively. The data samples contain $(471\ifmmode\pm\else\textpm\fi{}3)\ifmmode\times\else\texttimes\fi{}{10}^{6} B\overline{B}$ pairs recorded by the BABAR detector and $(772\ifmmode\pm\else\textpm\fi{}11)\ifmmode\times\else\texttimes\fi{}{10}^{6} B\overline{B}$ pairs recorded by the Belle detector. We measure the $CP$ asymmetry parameters $\ensuremath{-}{\ensuremath{\eta}}_{f}\mathcal{S}=+0.66\ifmmode\pm\else\textpm\fi{}0.10(\text{stat})\ifmmode\pm\else\textpm\fi{}0.06(\text{syst})$ and $\mathcal{C}=\ensuremath{-}0.02\ifmmode\pm\else\textpm\fi{}0.07(\text{stat})\ifmmode\pm\else\textpm\fi{}0.03(\text{syst})$. These results correspond to the first observation of $CP$ violation in ${\overline{B}}^{0}\ensuremath{\rightarrow}{D}_{CP}^{(*)}{h}^{0}$ decays. The hypothesis of no mixing-induced $CP$ violation is excluded in these decays at the level of 5.4 standard deviations.

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