Exchange Current Contributions to the Charge Radii of the Nucleons

Abstract

The exchange charge density 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 a constituent quark model with a spin and flavor dependent hyperfine and a linear confining interaction, which gives a quantitative description of the spectra for the light and strange baryons. The model gives proton and neutron charge radii in approximate agreement with the empirical results assuming reasonable values for the radii of the constituent quarks.