A vector-vector or vector-axial vector B-meson decay can be characterised by three complex helicity amplitudes, A+, A0 and A−, corresponding to meson helicity states λ = +1, 0 and −1, respectively. The A0 amplitude is expected to dominate due to the (V −A) nature of weak interactions and helicity conservation in strong interactions [1]. Most B decays that arise from tree level b → c transitions...

In past years we have witnessed remarkable progress in the study of exclusive charmless B decays. Experimentally, CLEO [1] has discovered many new two-body decay modes B ! K ; K; K; K ; K ; 0 ; !K and found a possible evidence for B ! K . Moreover, CLEO has provided new improved upper limits for many other decay modes. While all the measured channels are penguin dominated, the most recently obs...

We use the procedure of pinched-weight Finite Energy Sum Rules (pFESR) to determine the OPE coefficients a6, · · · , a16 of the flavor ud V-A correlator in terms of existing hadronic τ decay data. We show by appropriate weight choices that the error on the dominant d = 6 contribution, which is known to be related to the K → ππ matrix elements of the electroweak penguin operator in the chiral li...

We analyze the effects of a tree level flavor changing tcZ vertex induced by a mixing with new isosinglet Q = 2/3 quarks, on the effective bsZ vertex. We compute the contributions arising from the new electroweak penguin diagrams involving one insertion of the tcZ vertex. We show that a generalized GIM mechanism ensures the cancellation of the mass independent terms as well as of the new diverg...

In the heavy-quark limit, the hadronic matrix elements entering nonleptonic B-meson decays into two light mesons can be calculated from first principles including " nonfactorizable " strong-interaction corrections. The B → πK, ππ decay amplitudes are computed including electroweak penguin contributions, SU(3) violation in the light-cone distribution amplitudes, and an estimate of power correcti...

We extend in several respects our earlier work on O(p2) corrections to matrix elements of the electroweak penguin operator Oewp. First, to facilitate comparison with certain lattice studies we calculate O(p2) corrections to 〈π|Oewp|K〉 in the SU(3) limit of equal light quark masses. Next, we demonstrate how an apparent disagreement in the literature regarding whether higher order chiral contribu...

A new bound on the angle γ of the unitarity triangle is derived using experimental information on the CP-averaged branching ratios for the rare decays B → π±K0 and B → π0K±. The theoretical description is cleaner than the Fleischer–Mannel analysis of the decays B → π±K0 and B0 → πK in that the two decay rates differ only in a single isospin amplitude, which has a simple structure in the SU(3) l...

We study the effects of electroweak penguin (EWP) amplitudes in B meson decays into two charmless pseudoscalars in the approximation of retaining only the dominant EWP operators Q9 and Q10. Using flavor SU(3) symmetry, we derive a set of model-independent relations between EWP contributions and tree-level decay amplitudes one of which was noted recently by Neubert and Rosner. Two new applicatio...

Direct CP violation in B0 --> K+ pi- decay has emerged at the -10% level, but the asymmetry in B+ --> K+ pi0 mode is consistent with zero. This difference points towards possible new physics in the electroweak penguin operator. We point out that a sequential fourth generation, with sizable V(t' s)* V(t' b) and near maximal phase, could be a natural cause. We use the perturbative QCD factorizati...