The effect of realistic nuclear charge distributions on isotope shifts and towards the extraction of higher order nuclear radial moments

TL;DR

This paper explores how realistic models of nuclear charge distributions influence isotope shifts in atomic spectra and proposes methods to extract detailed nuclear charge information from experimental data.

Contribution

It introduces a novel approach combining atomic and nuclear theories to better interpret field shifts and extract higher order nuclear radial moments from isotope shift measurements.

Findings

Nuclear deformation affects field shifts measurably.

Variations in nuclear charge distribution diffuseness influence isotope shifts.

New methods enable extraction of detailed nuclear charge density information.

Abstract

Background: Atomic spectral lines from different isotopes display a small shift in energy, commonly referred to as the line isotope shift. One of the components of the isotope shift is the field shift, which depends on the extent and the shape of the nuclear charge density distribution. Purpose: To investigate how sensitive field shifts are with respect to variations in the nuclear size and shape and what information of nuclear charge distributions that can be extracted from measured field shifts. Methods: Nuclear properties are obtained from nuclear density functional theory calculations based on the Skyrme-Hartree-Fock-Bogoliubov approach. These results are combined with multiconfiguration Dirac-Hartree-Fock methods to obtain realistic field shifts. Results: Phenomena such as nuclear deformation and variations in the diffuseness of nuclear charge distributions give measurable contributions to the field shifts. Using a novel approach, we demonstrate the possibility to extract new information concerning the nuclear charge densities from the observed field shifts. Conclusions: Combining methods used in atomic and nuclear structure theory gives an improved description of field shifts. Extracting additional nuclear information from measured field shifts is possible in the near future with improved experimental methods.