Electroweak Penguins, Final State Interaction Phases, andCPViolation inB→KπDecays

The recently observed $B^{-}\to K^{-}{\pi }^0$, ${\overline{K}}^0{\pi }^{-}$ and ${\overline{B}}^0\to K^{-}{\pi }^{+}$ decay modes appear to have nearly equal branching ratios. This suggests that tree and electroweak penguins play an important role, and inclusion of the latter improves agreement between factorization calculation and experimental data. The value of $\gamma$ in the range of $90°–130°$ and $220°–260°$ is favored, while the ${\overline{B}}^0\to {\overline{K}}^0{\pi }^0$ rate is suppressed. Direct $\mathrm{CP}$ violation for $B\to K\pi$ modes can be large if final state interaction phases are large.