Exchange Current Contributions to the Charge Radii of the Nucleons

The exchange charge operators that correspond to the Fermi-invariant decomposition of quark-quark interactions have been constructed. Their effect on the electromagnetic charge radii of the nucleons, in combination with that of the relativistic corrections to the single-quark operator, has been studied with two constituent quark models with a spin and flavor dependent interquark interaction and a linear confining interaction, which give quantitative descriptions of the spectra for the light and strange baryons. One of the models gives both proton and neutron charge radii in agreement with the empirical results assuming reasonable values for the radii of the constituent quarks and $r^2_d>r^2_u$.