New aspects of B→ππ,πK and their implications for rare decays

We analyze the B→ππ,πK modes in the light of the most recent B-factory data, and obtain the following new results: (i) the B0d→π+π-,π-K+ modes prefer γ=(74±6) , which - together with vertical stroke Vub/Vcb vertical stroke - allows us to determine the ''true'' unitarity triangle and to search for CP-violating new-physics contributions to B0d- anti B0d mixing; (ii) the B→πK puzzle reflected in particular by the low experimental value of the ratio Rn of the neutral B→πK rates persists and still favors new physics in the electroweak penguin sector with a new CP-violating phase φ∝-90 , although now also φ∝+90 can bring us rather close to the data; (iii) the mixing-induced B0d→π0KS CP asymmetry is a sensitive probe of the sign of this phase, and would currently favor φ∝ +90 , as well as the direct CP asymmetry of B±→π0K±, which suffers, however, from large hadronic uncertainties; (iv) we investigate the sensitivity of our B→πK analysis to large non-factorizable SU(3)-breaking effects and find that their impact is surprisingly small so that it is indeed exciting to speculate on new physics; (v) assuming that new physics enters through Z0 penguins, we study the interplay between B→πK and rare B,K decays and point out that the most recent B-factory constraints for the latter have interesting implications, bringing us to a few scenarios for the future evolution of the data, where also the mixing-induced CP violation in B0d→π0KS plays a prominent role. (orig.)