# Cabibbo-Kobayashi-Maskawa-favored $B$ decays to a scalar meson and a $D$ meson

## TL;DR

This paper calculates branching ratios for specific B meson decays to scalar and D mesons using perturbative QCD, providing predictions testable at LHCb and Belle-II, and exploring implications for scalar meson structure and new physics.

## Contribution

It offers the first comprehensive calculation of 72 B decay modes to scalar and D mesons within the two-quark model using perturbative QCD, including potential for new physics signals.

## Key findings

- Most branching ratios range from 10^{-4} to 10^{-7}.
- Certain decay modes can probe scalar meson structure.
- Ratios of branching fractions can determine scalar meson mixing angles.

## Abstract

Within the perturbative QCD approach, we investigated the Cabibbo-Kobayashi-Maskawa-favored $B \to \overline{D} S$ ("$S$" denoting the scalar meson) decays on the basis of the two-quark picture. Supposing the scalar mesons are the ground states or the first excited states, we calculated the the branching ratios of 72 decay modes. Most of the branching ratios are in the range $10^{-4}$ to $10^{-7}$, which can be tested in the ongoing LHCb experiment and the forthcoming Belle-II experiment. Some decays, such as $B^+ \to \overline{D}^{(*)0} a_0^+(980/1450)$ and $B^+ \to D^{(*)-} a_0^+(980/1450)$, could be used to probe the inner structure and the character of the scalar mesons, if the experiments are available. In addition, the ratios between the $Br(B^0\to \overline{D}^{(*)0}\sigma)$ and $Br(B^0\to \overline{D}^{(*)0}f_0(980))$ provide a potential way to determine the mixing angle between $\sigma$ and $f_0(980)$. Moreover, since in the standard model these decays occur only through tree operators and have no $CP$ asymmetries, any deviation will be signal of the new physics beyond the standard model.