Weak Phase $\gamma$ From Ratio of $B\to K\pi$ Rates

Abstract

The ratio of partial decay rates for charged and neutral $B$ mesons to $K\pi$ final states provides information on the weak phase $\gamma \equiv \mathrm{Arg}(V_{ub}^{\ast })$ when augmented with information on the CP-violating asymmetry in the $K^{\pm }{\pi }^{\mp }$ mode. The requirements for a useful determination of $\gamma$ are examined in the light of present information about the decays $B^0\to K^{+}{\pi }^{-}$, $B^{+}\to K^0{\pi }^{+}$, and the corresponding charge-conjugate modes. The effects of electroweak penguins and rescattering corrections are noted, and proposals are made for estimating and measuring their importance.

Comments: 16 pages, latex, 3 figures, revised version sent to Phys. Rev. D