Model-independent information on gamma from B^+- -> pi K Decays

Abstract

Measurements of the rates for the hadronic decays B^+- -> pi K can be used to derive information on the weak phase gamma=arg(V_ub^*) in a largely model-independent way. Hadronic uncertainties can be reduced to the level of nonfactorizable contributions to the decay amplitudes that are power-suppressed in Lambda/m_b and, in addition, either violate SU(3) flavor symmetry or are doubly Cabibbo suppressed. Various strategies to obtain bounds on gamma and to extract its value with small theoretical uncertainty are described. The potential of B^+- -> pi K decays for probing physics beyond the Standard Model is also discussed.

Comments: 10 pages, 5 figures, uses espcrc2.sty (included); invited talk presented at the High-Energy Physics International Euroconference on Quantum Chromo-Dynamics (QCD 99), Montpellier, France, 7--13 July 1999