Chinese Acad Sci, Inst High Energy Phys, Beijing 100039, Peoples R China
; CCAST, World Lab, Beijing 100080, Peoples R China
In this paper, we study nonleptonic charmless B decays to two light pseudoscalar mesons within the frame of QCD factorization, including the contributions from the chirally enhanced power corrections and weak annihilation. Predictions for the CP-averaged branching ratios and CP-violating asymmetries are given. Within the reasonable range of the parameters, we find that our predictions for the branching ratios of B-->PP are consistent with the present experimental data. But because of the logarithmic divergences at the end points in the hard spectator scatterings and weak annihilation, there are still large uncertainties in these predictions.