Study of $B_c \to DS$ Decays in PQCD Approach

TL;DR

This paper analyzes 40 $B_c o DS$ decay modes using perturbative QCD, predicting branching fractions and CP asymmetries, with some results measurable at current or future colliders.

Contribution

It provides the first detailed PQCD analysis of $B_c o DS$ decays including two scalar meson scenarios, highlighting dominant annihilation contributions and potential experimental observability.

Findings

Some branching fractions are in the range $[10^{-5}, 10^{-4}]$.

Certain decay modes exhibit large CP asymmetries.

Predictions are relevant for current LHCb and future high-energy colliders.

Abstract

Within the framework of perturbative QCD approach based on $k_T$ factorization, we studied 40 $B_c \to DS$ decay modes in the leading order and leading power, where "S" stands for the light scalar meson. Under two different scenarios (S1 and S2) for the description of scalar mesons, we explored the branching fractions and related CP asymmetries. As a heavy meson consisting of two heavy quarks with different flavor, the light-cone distribution amplitude of $B_c$ meson has not been well defined, so the $\delta$-function is adopted. The contributions of emission diagrams are suppressed by the vector decay constants and CKM elements, the contributions of annihilation are dominant. After the calculation, we found some branching fractions are in the range of $[10^{-5}, 10^{-4}]$, which could be measured in the current LHCb experiment, and other decays with smaller branching fractions will be tested at the high-energy colliders in future. Furthermore, some decay modes have large CP asymmetries, but they are unmeasurable currently due to the small branching fractions.