Implications of CP Asymmetry Limits for $B\to K\pi$ and $B\to \pi \pi$

Abstract

Recent experimental limits for the direct CP asymmetries in $B^0\to K^{+}{\pi }^{-}$, $B^{+}\to K^{+}{\pi }^0$, $B^{+}\to K^0{\pi }^{+}$, and $B^0\to {\pi }^{+}{\pi }^{-}$, and for the indirect CP asymmetry in $B^0\to {\pi }^{+}{\pi }^{-}$, are combined with information on CP-averaged branching ratios to shed light on weak and strong phases. At present such bounds favor $\gamma \ge 60^{\circ }$ at the $1\sigma$ level. The prospects for further improvements are discussed.

Comments: 16 pages, LaTeX, 3 figures, revised version to be published in Phys. Rev. D. References added and updated