means of time-of-flight. A mono-energetic peak was observed, which is interpreted as the
formation of a new kind of neutral tribaryon S0 (3115) with isospin T= 1 and strangeness
S=− 1. The mass and width of the state were deduced to be 3117.0− 4.4+ 1.5 MeV/c2 and<
21MeV/c2, respectively. The state mainly decays into ΣNN.