Ground-state baryon mass splittings from unitarity

Abstract

We discuss the hadronic mass shifts of the lightest baryons generated by coupled-channel effects. The contributions from different thresholds are assumed to be related by $\mathrm{SU}{\mathrm{}\left(6\right)\mathrm{}}_W$ symmetry. Using very general arguments, we derive mass formulas for the relative splittings of $\Delta -N$, ${\Sigma }^{*}-\Sigma -\Lambda$, and ${\Xi }^{*}-\Xi$, which are satisfied by experiment to within 20%.