Weak phase γ from the ratio ofB→Kπrates

The ratio of partial decay rates for charged and neutral $B$ mesons to $K\pi$ final states provides information on the weak phase $\gamma \equiv \mathrm{Arg}{(V}_{\mathrm{ub}}^{*})$ when augmented with information on the $\mathrm{CP}$-violating asymmetry in the $K^{\pm }{\pi }^{\mp }$ mode. The requirements for a useful determination of γ 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 penguin diagrams and rescattering corrections are noted, and proposals are made for estimating and measuring their importance.