QCD Factorization for Charmless Hadronic B_s Decays Revisited

TL;DR

This paper re-examines charmless B_s decay rates and CP asymmetries using QCD factorization, incorporating subleading corrections to address previous puzzles and predict small mixing-induced CP asymmetries sensitive to new physics.

Contribution

It introduces subleading power corrections into QCDF calculations for B_s decays, improving agreement with experimental data and providing new testable relations and predictions.

Findings

Many B_s decay modes related to B_d decays via symmetry.

Predicted small mixing-induced CP asymmetries in the Standard Model.

Potential to identify new physics through CP asymmetry measurements.

Abstract

Branching fractions and CP-violating asymmetries of charmless $\bar B_s\to PP, VP, VV$ decays (P and V denoting pseudoscalar and vector mesons, respectively) are re-examined 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 $\pi^0\pi^0$ and $\rho^0\pi^0$ modes in the $B_{u,d}$ sector. Many of the $B_s\to h_1h_2$ decays can be related to $B_d\to h_1h_2$ 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.