Strange tribaryons

We use two-body potentials derived from a constituent quark cluster model to analyze the bound-state problem of the $\mathrm{\Sigma }NN$ system. The observables of the two-body subsystems, $NN$ and $\mathrm{\Sigma }N$, are well reproduced. We do not find $\mathrm{\Sigma }NN$ bound states, but there are two attractive channels with a resonance close above the three-body threshold. These channels are the $(I,J)=(1,1\mathrm{/}2)$ and $(0,1\mathrm{/}2)$, their quantum numbers, widths and energy ordering consistent with the recently measured strange tribaryons from the ${}^4\mathrm{H}\mathrm{e}(K_{\mathrm{s}\mathrm{t}\mathrm{o}\mathrm{p}\mathrm{p}\mathrm{e}\mathrm{d}}^{-},N)$ reactions in the KEK PS E471 experiment.