Weak Coupling Phase from Decays of Charged B Mesons to $πK$ and $ππ$

Abstract

The theory of $CP$ violation based on phases in weak couplings in the Cabibbo-Kobayashi-Maskawa (CKM) matrix requires the phase $γ\equiv {\rm Arg~} V^*_{ub}$ (in a standard convention) to be nonzero. A measurement of $γ$ is proposed based on charged $B$ meson decay rates to $π^+ K^0$, $π^0 K^+$, $π^+ π^0$, and the charge-conjugate states. The corresponding branching ratios are expected to be of the order of $10^{-5}$. (submitted to Physical Review Letters)