Branching ratio and CP asymmetry of B_s→K₀^*(1430)η^(') decays in the PQCD approach

Abstract: In the two-quark model supposition for K₀^*(1430), which can be viewed as either the first excited state (Scenario Ⅰ) or the lowest lying state (Scenario Ⅱ), the branching ratios and the direct CP-violating asymmetries for decays B_s⁰→K₀^*0(1430)η^(') are studied by employing the perturbative QCD factorization approach. We find the following results: (a) The CP averaged branching ratios of B_s⁰→K₀^*0(1430)η and B_s⁰→K₀^*0(1430)η' are small and both in the order of 10^-7. If one views K₀^*(1430) as the lowest lying state, B (B_s⁰→K₀^*0(1430)η)≈3.9×10^-7 and B (B_s⁰→K₀^*0(1430)η')≈7.8×10^-7. (b) While the direct CP-violating asymmetries of these two decays are not small: if we still take the parameters of K₀^*(1430) in scenario Ⅱ, A_CP^dir (B_s⁰→K₀^*0(1430)η)≈56.2% and A_CP^dir (B_s⁰→K₀^*0(1430)η')≈2.4%. (c) The annihilation contributions will play an important role in accounting for future data, because both the branching ratios and the direct CP asymmetries of these two decays are sensitive to the annihilation type contributions.