The ${\Upsilon}(nS)$ ${\to}$ $B_{c}^{\ast}{\pi}$, $B_{c}^{\ast}K$ decays with perturbative QCD approach

TL;DR

This paper investigates rare weak decay modes of the bottomonium ${}(nS)$ meson into $B_c^*$ and a light meson using perturbative QCD, predicting very small but potentially measurable branching ratios for future experiments.

Contribution

It is the first study to analyze ${}(nS)$ decays into $B_c^*$ and light mesons via weak interactions using the perturbative QCD approach.

Findings

Branching ratios estimated up to $10^{-10}$ for ${}(nS)\to B_c^*\pi$ decays.

Branching ratios estimated up to $10^{-11}$ for ${}(nS)\to B_c^*K$ decays.

Potential for future experimental detection at LHC and SuperKEKB.

Abstract

Besides the traditional strong and electromagnetic decay modes, ${\Upsilon}(nS)$ meson can also decay through the weak interactions within the standard model of elementary particle. With anticipation of copious ${\Upsilon}(nS)$ data samples at the running LHC and coming SuperKEKB experiments, the two-body nonleptonic bottom-changing ${\Upsilon}(nS)$ ${\to}$ $B_{c}^{\ast}{\pi}$, $B_{c}^{\ast}K$ decays ($n$ $=$ 1, 2, 3) are investigated with perturbative QCD approach firstly. The absolute branching ratios for ${\Upsilon}(nS)$ ${\to}$ $B_{c}^{\ast}{\pi}$ and $B_{c}^{\ast}K$ decays are estimated to reach up to about $10^{-10}$ and $10^{-11}$, respectively, which might possibly be measured by the future experiments.