Study of the Suppressed Decays $B^{\pm }\to [K^{\mp }{\pi }^{\pm }{]}_D{K}^{\pm }$ and $B^{\pm }\to [K^{\mp }{\pi }^{\pm }{]}_D{\pi }^{\pm }$ at Belle

Abstract

We report an updated study of the suppressed decays $B^{-}\to [K^{+}{\pi }^{-}{]}_D{K}^{-}$ and $B^{-}\to [K^{+}{\pi }^{-}{]}_D{\pi }^{-}$ where $[K^{+}{\pi }^{-}{]}_D$ indicates that the $K^{+}{\pi }^{-}$ pair originates from a neutral $D$ meson. A data sample containing 386 million $B\bar{B}$ pairs recorded at the ${\rm Y}(4S)$ resonance with the Belle detector at the KEKB asymmetric $e^{+}{e}^{-}$ storage ring is used. This decay mode is sensitive to the CKM angle ${\varphi }_3$. We do not see a significant signal for $B^{-}\to [K^{+}{\pi }^{-}{]}_D{K}^{-}$, and we set a limit on the ratio of B decay amplitudes $r_B<0.18$ at the 90% confidence level. We measure the CP asymmetry of the $B^{-}\to [K^{+}{\pi }^{-}{]}_D{\pi }^{-}$ mode, ${\mathcal{A}}_{D\pi }=0.10\pm 0.22(stat)\pm 0.02(syst)$.

arXiv comment11 pages, 5 figures. Contributed to EPS International Europhysics Conference on High Energy Physics (HEPP-EPS 2005), Lisbon, Portugal, 21-27 Jul 2005