Probing the CKM angle gamma with B ->pi K decays

The decays B+/- --> pi(+/-) K and B-d --> pi(-/+) K+/- were observed by the CLEO collaboration last year; they may play an important role to probe the angle gamma of the unitarity triangle of the CKM matrix. After a general p arametrization of their decay amplitudes within the Standard Model, strateg ies to constrain and determine the CKM angle gamma with the help of the cor responding CP-conserving and CP-violating observables are briefly reviewed. The theoretical accuracy of these methods is limited by certain rescatteri ng and electroweak penguin effects. It is emphasized that the rescattering processes can be included in the bounds on gamma by using additional experi mental information on B+/- --> K+/- K decays, and steps towards the control of electroweak penguins are pointed out.