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 b → s electroweak penguin amplitude can be determined in a two-step procedure involving i) BR(B+ → π0K+), BR(B− → π0K−), BR(B+ → π+K0) and ii) either BR(Bd0 → π−K+), BR(Bd0 → π+K−) or aCP(t) of the mode Bs → K+K−. The determination employing the B → πK transitions is not affected by SU(3)-breaking effects. Relating the b → s electroweak penguin amplitude to the b → d 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.