Introduction to the Theory of Field Shifts in Optical Spectra

Abstract

The interaction between atomic electrons (and muons) and nuclei is electromagnetic—there is no strong interaction; the nuclear matter distribution cannot be studied, but the nuclear charge distribution can. The nuclear charge distribution can also be studied by scattering electrons off nuclei elastically. Since the first scattering experiments of Lyman et al. (1951) the size of the charge distribution of many nuclei have been found. It has been found that, to a very crude first approximation, nuclei have a uniform charge density ρ,out to a radius R,where there is a sharp edge. The internucleon strong interaction is of such short range that in all but the smallest nuclei it is saturated. This means that nuclear matter has a constant density independent of the number of nucleons in the nucleus A.