Charmless $B_s\to V S$ Decays in PQCD Approach

TL;DR

This paper calculates branching ratios and CP asymmetries for $B_s o VS$ decays using PQCD, providing predictions that can help determine scalar meson structures in upcoming experiments.

Contribution

It offers the first detailed PQCD-based predictions for $B_s o VS$ decays considering different scalar meson scenarios, aiding in understanding scalar meson structures.

Findings

Most branching fractions predicted between 10^{-7} and 10^{-5}.

Certain decay modes are highly sensitive to scalar meson scenario assumptions.

Large direct CP asymmetries found in some decay channels.

Abstract

In this work, we investigate the $B_s\to V S$ 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 $B_s\to VS$ 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 $B_s\to \kappa(800)(K_0^*(1430))K^*$ decays. It is found that the branching fractions of $B_s\to K_0^{*0}(1430)\bar{K}^{*0}$ and $B_s\to K_0^{*+}(1430)\bar{K}^{*-}$ 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 $B_s \to a_0^+(1450)K^{*-}$ and the $B_s\to f_0(1500) K^{*0}$ decays. Since the experimental measurements of $B_s\to VS$ 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.