Observation of $\psi (3686)\to p{K}^{-}{K}_S^0{\bar{\Xi }}^0+c.c.$

Abstract

Using a sample of $(2.712\pm 0.014)\times 10^9$ $\psi (3686)$ events collected with the BESIII detector, the decay of $\psi (3686)\to p{K}^{-}{K}_S^0{\bar{\Xi }}^0+c.c.$ is observed for the first time with a statistical significance of $11.5\sigma$. The branching fraction of this decay is measured to be $(2.84\pm 0.40\pm 0.25)\times 10^{-6}$, where the first and second uncertainties are statistical and systematic, respectively. This measurement extends the experimental information on rare multi-strange $\psi (3686)$ decays and provides an experimental reference for future studies of related decay modes.

11 pages, 4 figures, 2 tables