Type: Article
Publication Date: 2004-05-20
Citations: 14
DOI: https://doi.org/10.1103/physrevlett.92.201802
We present measurements of branching fractions and $CP$-violating asymmetries in decays of $B$ mesons to two-body final states containing a ${K}^{0}$. The results are based on a data sample of approximately $88\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $\ensuremath{\Upsilon}(4S)\ensuremath{\rightarrow}B\overline{B}$ decays collected with the BABAR detector at the PEP-II asymmetric-energy $B$ Factory at SLAC. We measure $\mathcal{B}({B}^{+}\ensuremath{\rightarrow}{K}^{0}{\ensuremath{\pi}}^{+})=(22.3\ifmmode\pm\else\textpm\fi{}1.7\ifmmode\pm\else\textpm\fi{}1.1)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$, $\mathcal{B}({B}^{0}\ensuremath{\rightarrow}{K}^{0}{\ensuremath{\pi}}^{0})=(11.4\ifmmode\pm\else\textpm\fi{}1.7\ifmmode\pm\else\textpm\fi{}0.8)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$, $\mathcal{B}({B}^{+}\ensuremath{\rightarrow}{\overline{K}}^{0}{K}^{+})<2.5\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$, and $\mathcal{B}({B}^{0}\ensuremath{\rightarrow}{K}^{0}{\overline{K}}^{0})<1.8\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$, where the first uncertainty is statistical and the second is systematic, and the upper limits are at the $90%$ confidence level. In addition, the following $CP$-violating asymmetries have been measured: ${\mathcal{A}}_{CP}({B}^{+}\ensuremath{\rightarrow}{K}^{0}{\ensuremath{\pi}}^{+})=\ensuremath{-}0.05\ifmmode\pm\else\textpm\fi{}0.08\ifmmode\pm\else\textpm\fi{}0.01$ and ${\mathcal{A}}_{CP}({B}^{0}\ensuremath{\rightarrow}{K}^{0}{\ensuremath{\pi}}^{0})=0.03\ifmmode\pm\else\textpm\fi{}0.36\ifmmode\pm\else\textpm\fi{}0.11$.