Observation of a Doubly-strange Hyperon $\hat{I}ž(1720)$ in $J/\ddot{I}ˆ\to K^{-}\hat{I}{\pounds }^0\bar{\hat{I}}{ž}^{+}+c.c.$

BESIII Collaboration, M. Ablikim, M. N. Achasov +758

Based on a sample of $(10087\pm 44)\times 10^6$ $J/\ddot{I}ˆ$ events collected with the BESIII detector at BEPCII, we report the first observation of the decay $J/ψ\rightarrow K^- Σ^0…