Weak phases γ and α from B⁺, or B⁰ and B_s decays

An improved flavor SU(3) method is presented for determining the weak angle γ of the unitarity triangle using decay rates for B⁺ → Kπ,B⁺ → K⁺K̄⁰ and B⁺ → π⁺ η (or B⁰ → Kπ and B_s → Kπ), their CP-conjugate modes and the CP-averaged rate for B^±→π^±π⁰. Rescattering (color-suppressed) contribution in B⁺(B⁰) → Kπ is subtracted away. The only significant SU(3) breaking effects are accounted for in the factorization approximation of tree amplitudes. The weak angle α is obtained as a byproduct.