Two-body modes of B mesons and the CP-b triangle

The study of charmless two-body decays of B mesons is currently one of the hottest topics in B physics. QCD factorization provides the theoretical framework for a systematic analysis of such decays. A global fit to → πK, ππ branching fractions, combined with knowledge on |Vub|, establishes the existence of a CP-violating phase in the bottom sector of the CKM matrix and tends to favor values of γ near 90°, somewhat larger than those suggested by the standard analysis of the unitarity triangle. A novel construction of the unitarity triangle is presented, which is independent of B-B and K-K mixing.