# The ${\Upsilon}(nS)$ ${\to}$ $B_{c}D_{s}$, $B_{c}D_{d}$ decays with perturbative QCD approach

## TL;DR

This paper investigates the weak decay processes of the upsilon meson into Bc and Ds or Dd mesons using perturbative QCD, predicting extremely rare branching ratios that could be observed in future experiments.

## Contribution

First application of the pQCD approach to study these specific upsilon decay channels, providing quantitative predictions for their branching ratios.

## Key findings

- Branching ratio for ${mbda}(nS){\to}B_{c}D_{s}$ is about 10^{-10}.
- Branching ratio for ${mbda}(nS){\to}B_{c}D_{d}$ is about 10^{-11}.
- Predicted decay rates are potentially measurable in future experiments.

## Abstract

The ${\Upsilon}(nS)$ ${\to}$ $B_{c}D_{s}$, $B_{c}D_{d}$ weak decays are studied with the pQCD approach firstly. It is found that branching ratios ${\cal B}r({\Upsilon}(nS){\to}B_{c}D_{s})$ ${\sim}$ ${\cal O}(10^{-10})$ and ${\cal B}r({\Upsilon}(nS){\to}B_{c}D_{d})$ ${\sim}$ ${\cal O}(10^{-11})$, which might be measurable in the future experiments.