Mass- and field-shift isotope parameters for the $2s - 2p$ resonance doublet of lithium-like ions

TL;DR

This paper calculates relativistic isotope shift parameters for lithium-like ions' $2s - 2p$ transitions, enabling more accurate nuclear charge radius measurements via dielectronic recombination data.

Contribution

It provides new relativistic mass- and field-shift factors for lithium-like ions, incorporating electron correlation and Breit interaction effects systematically.

Findings

Mass and field shifts are significant and competitive along the isoelectronic sequence.

Accurate isotope shift parameters are essential for nuclear charge radius inference.

Relativistic effects are crucial for precise calculations in highly-charged ions.

Abstract

It was recently shown that dielectronic recombination measurements can be used for accurately inferring changes in the nuclear mean-square charge radii of highly-charged lithium-like neodymium [Brandau et al., Phys. Rev. Lett. 100 073201 (2008)]. To make use of this method to derive information about the nuclear charge distribution for other elements and isotopes, accurate electronic isotope shift parameters are required. In this work, we calculate and discuss the relativistic mass- and field-shift factors for the two $2s ^{2}S_{1/2} - 2p ^{2}P^{o}_{1/2,3/2}$ transitions along the lithium isoelectronic sequence. Based on the multiconfiguration Dirac-Hartree-Fock method, the electron correlation and the Breit interaction are taken into account systematically. The analysis of the isotope shifts for these two transitions along the isoelectronic sequence demonstrates the importance and competition between the mass shifts and the field shifts.