The role of B_s→Kπ in determining the weak phase γ

Abstract

The decay rates for B⁰→K⁺π⁻, B⁺→K⁰π⁺, and the charge-conjugate processes were found to provide information on the weak phase $\text{γ≡}\text{Arg}\text{(V}{}_{\mathrm{ub}}{}^{\mathrm{\ast }}\text{)}$ when the ratio r of weak tree and penguin amplitudes was taken from data on B→ππ or semileptonic B→π decays. We show here that the rates for B_s→K⁻π⁺ and $\text{B}\text{̄}{}_{\mathrm{s}}\text{→K}{}^{\mathrm{+}}\text{π}{}^{\mathrm{-}}$ can provide the necessary information on r, and estimate the statistical accuracy of forthcoming measurements at the Fermilab Tevatron.