QCD factorization for charmless hadronic Bs decays revisited

Branching fractions and CP-violating asymmetries of charmless Bs→PP, VP, VV decays (P and V denoting pseudoscalar and vector mesons, respectively) are reexamined in the framework of QCD factorization (QCDF). We take into account subleading power corrections to the penguin annihilation topology and to color-suppressed tree amplitudes that are crucial for resolving the CP puzzles and rate deficit problems with penguin-dominated two-body decays and color-suppressed tree-dominated π0π0 and ρ0π0 modes in the Bu,d sector. Many of the Bs→h1h2 decays can be related to Bd→h1h2 ones via U-spin or SU(3) symmetry. Some useful model-independent relations can be derived and tested. Mixing-induced CP asymmetries for many of the penguin-dominated decays are predicted to be very small in the standard model. They are sensitive to new physics and offer rich possibilities of new discoveries. Measurements of direct CP-violating asymmetries can be used to discriminate QCDF from other competing approaches such as pQCD and soft-collinear effective theory.