Isotope Shift of Nuclear Charge Distributions

Abstract

The energy-density formalism is applied to the study of the isotope shift of nuclear charge distributions. It allows us to determine the part of the shift due to a statistical change in the proton densities. The study is improved by a shell-model calculation based on the Thomas-Fermi potential. The charge distributions are in relatively good agreement with experiment. However, the present model cannot reproduce the part of the shift due to nonmonotonic changes in charge distributions. These nonmonotonic effects are of a more complicated origin; they are of the same order of magnitude as the statistical shifts. In the case of the pair of ${\mathrm{Ca}}^{40}$-${\mathrm{Ca}}^{48}$ our results are consistent with shifts calculated in self-consistent (Hartree-Fock) methods.