Determination of the Weak Phaseγfrom Rate Measurements inB±→πK,ππDecays

A method is described which, under the assumption of SU(3) symmetry, allows one to determine the angle $\gamma =\arg \left(V_{\mathrm{ub}}^{*}\right)$ of the unitarity triangle from time-independent measurements of the branching ratios for the rare two-body decays $B^{+}\to {\pi }^0{K}^{+}$ and $B^{-}\to {\pi }^0{K}^{-}$, as well as of the $\mathrm{CP}$-averaged branching ratios for the decays $B^{\pm }\to {\pi }^{\pm }{K}^0$ and $B^{\pm }\to {\pi }^{\pm }{\pi }^0$, all of which are of order ${10}^{-5\mathrm{}}$. The effects of electroweak penguin operators are included in a model-independent way, and SU(3)-breaking corrections are accounted for in the factorization approximation.