Observation of $ψ(3686) \rightarrow Λ\barΛ η^{\prime}$ decay

Abstract

Using a sample of $(27.12\pm 0.14) \times 10^{8}$ $ψ(3686)$ events collected with the BESIII detector, the decay $ψ(3686) \to Λ\barΛ η'$ with $η'$ subsequently decaying into $γπ^+ π^-$ and $ηπ^+ π^-$ is observed for the first time. The branching fraction of $ψ(3686) \to Λ\barΛη'$ is measured to be $(7.34\pm0.94(stat.)\pm0.43(sys.))\times10^{-6}$. No resonant structures are evident in the $Λη'$, $\barΛη'$ and $Λ\barΛ$ mass spectra.