Towards the control over electroweak penguins in nonleptonic B-decays

We present strategies for determining electroweak penguins from experimental data. Using the CKM-angle γ as one of our central inputs and making some reasonable approximations, we show that the b̄ → s̄ electroweak penguin amplitude can be determined in a two-step procedure involving i) BR(B⁺ → π⁰ K⁺), BR(B^- → π⁰ K^-), BR(B⁺ → π⁺ K⁰) and ii) either BR(B⁰_d → π^- K⁺), BR(B̄⁰_d → π⁺ K^-) or a_CP (t) of the mode B_s → K⁺ K^-. The determination employing the B → πK transitions is not affected by SU(3)-breaking effects. Relating the b̄ → s̄ electroweak penguin amplitude to the b̄ → d̄ case through SU(3) symmetry arguments, we are in a position to estimate the electroweak penguin uncertainty affecting the extraction of the CKM-angle α by using isospin relations among B → ππ decays. Our results allow in principle the determination of CKM-phases in a variety of B-decays.