Reexamining charmlessB→PVdecays in the QCD factorization approach

Abstract

Using the QCD factorization approach, we reexamine the two-body hadronic charmless B-meson decays to final states involving a pseudoscalar (P) and a vector (V) meson, with inclusion of the penguin contractions of spectator-scattering amplitudes induced by the b -> Dg(*)g(*) (where D=d or s, and g(*) denotes an off-shell gluon) transitions, which are of order alpha(2)(s). Their impacts on the CP-averaged branching ratios and CP-violating asymmetries are examined. We find that these higher order penguin contraction contributions have significant impacts on some specific decay modes. Since B ->pi K-*, K rho decays involve the same electroweak physics as B ->pi K puzzles, we present a detailed analysis of these decays and find that the five R-ratios for the B ->pi K-*, K rho system are in agreement with experimental data except for R(pi K-*). Generally, these new contributions are found to be important for penguin-dominated B -> PV decays.