Charmless B_srightarrow V S decays in PQCD approach

Abstract

In this work, we investigate the B_srightarrow V S decays in the perturbative QCD approach, where V and S denote the vector meson and scalar meson respectively. Based on the two-quark structure, considering two different scenarios for describing the scalar mesons, we calculate the branching fractions and the direct CP asymmetries of all B_srightarrow VS decays. Most branching fractions are predicted to be at 10^{-7} to 10^{-5}, which could be measured in the LHCb and Belle-II experiments, especially for these color-allowed decays B_srightarrow kappa (800)(K_0^*(1430))K^* and B_srightarrow K_0^{*-}(1430)rho ^+. It is found that the branching fractions of B_srightarrow K_0^{*0}(1430){bar{K}}^{*0} and B_srightarrow K_0^{*+}(1430){bar{K}}^{*-} are very sensitive to the scenarios, which can be used to determine whether K_0^{*0}(1430) belongs to the ground state or the first excited state, if the data were available. We also note that some decays have large direct CP asymmetries, some of which are also sensitive to the scenarios, such as the B_s rightarrow a_0^+(1450)K^{*-} and the B_srightarrow f_0(1500) K^{*0} decays. Since the experimental measurements of B_srightarrow VS decays are on the way, combined with the available data in the future, we expect the theoretical predictions will shed light on the structure of the scalar mesons.