The "Hole" In He

Abstract

The measurement and analysis of electron scattering from He-3 and He-4 by Sick and collaborators reported 20 years ago remains a matter of current interest. By unfolding the measured free-proton charge distribution, they deduced a depression in the central point nucleon density, which is not found in few-body calculations based on realistic potentials. We find that using wave functions from such calculations we can obtain good fits to the He charge distributions under the assumption that the proton charge size expands toward the center of the nucleus. The relationship to 6-quark Chromo-Dielectric Model calculations, is discussed. The expansion is larger than than the predictions of mean field bag calculations by others or our CDM calculations in the independent pair approximation. There is interest here in the search for a "smoking gun" signal of quark substructure.