Isotope shifts in $^{20,22}$Ne -- Precision measurements and global analysis in the framework of intermediate coupling

TL;DR

This paper presents high-precision measurements and comprehensive analysis of isotope shifts in neon isotopes, revealing electronic, nuclear, and relativistic effects, and demonstrating strong agreement between experimental data and theoretical calculations.

Contribution

It provides the first global fit of isotope shifts for all low-lying neon levels, combining new measurements with ab initio calculations and a novel parametric interpretation.

Findings

High-precision isotope shift data for $^{20}$Ne and $^{22}$Ne

Global fit of all fifty low-lying neon levels

Excellent agreement between experiment and ab initio theory

Abstract

We report new precision measurements of the $^{20}$Ne--$^{22}$Ne isotope shift for several transitions, as well as state-of-the-art, \textit{ab initio} field-shift calculations. Our results are combined with historical measurements in a global fit to obtain the isotope shifts of all fifty low-lying neon levels with high precision. These level shifts show a wealth of electronic, nuclear, and relativistic phenomena. Relying on the analogy between mass shift and fine-structure operators, we explain this plethora of neon level-shifts utilizing a small number of effective parameters in a global parametric investigation. This investigation provides a birds-eye view on the isotope shift phenomena in noble gasses. From this vantage point, we reinterpret every effort made to calculate neon mass-shifts \textit{ab initio}, and show that a remarkable agreement between experiment and theory is obtained.