Observation of $\psi(3686) \rightarrow \Lambda \bar{\Lambda} \eta^{\prime}$ decay

TL;DR

This paper reports the first observation of the decay process $ ext{psi}(3686) o ext{Lambda} ar{ ext{Lambda}} ext{eta'}$ using a large data sample, measuring its branching fraction and analyzing the mass spectra for resonant structures.

Contribution

First observation of the decay $ ext{psi}(3686) o ext{Lambda} ar{ ext{Lambda}} ext{eta'}$ with a measured branching fraction and no evident resonant structures in the mass spectra.

Findings

Branching fraction measured as (7.34 ± 0.94(stat.) ± 0.43(sys.))×10^{-6}

Decay observed for the first time

No resonant structures found in mass spectra

Abstract

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