# Study on the ${\Upsilon}(1S)$ ${\to}$ $B_{c}D_{s}$ decay

## TL;DR

This paper estimates the branching ratio and CP asymmetry of the ${
S}$ decay to $B_c D_s$ using perturbative QCD, finding a very small CP asymmetry and a potentially measurable branching ratio.

## Contribution

It provides the first perturbative QCD estimate of the ${
S}$ decay to $B_c D_s$, including predictions for CP asymmetry and branching ratio.

## Key findings

- CP asymmetry is close to zero.
- Branching ratio is estimated to be greater than 10^{-10}.
- Potential for measurement at future experiments.

## Abstract

The branching ratio and direct $CP$ asymmetry of the ${\Upsilon}(1S)$ ${\to}$ $B_{c}D_{s}$ weak decay are estimated with the perturbative QCD approach. It is found that (1) The direct $CP$-violating asymmetry is close to zero. (2) the branching ratio ${\cal B}r({\Upsilon}(1S){\to}B_{c}D_{s})$ ${\gtrsim}$ $10^{-10}$ might be measurable at the future experiments.