Isospin Splittings of Baryons

We discuss the isospin-breaking mass differences among baryons, with particular attention in the charm sector to the ${\mathrm{\Sigma }}_c^{+}-{\mathrm{\Sigma }}_c^0$, ${\mathrm{\Sigma }}_c^{++}-{\mathrm{\Sigma }}_c^0$, and ${\mathrm{\Xi }}_c^{+}-{\mathrm{\Xi }}_c^0$ splittings. Simple potential models cannot accommodate the trend of the available data on charm baryons. More precise measurements would offer the possibility of testing how well potential models describe the non-perturbative limit of QCD.