# Electron-correlation effects in the $g$-factor of light Li-like ions

## TL;DR

This paper analyzes electron-correlation effects on the $g$-factor of light Li-like ions using NRQED and $1/Z$ expansion methods, providing unified theoretical predictions for these ions.

## Contribution

It introduces a combined approach of NRQED and $1/Z$ expansion calculations to accurately predict the $g$-factor of light Li-like ions, advancing theoretical precision.

## Key findings

- Identified the $1/Z$-expansion contributions to the $g$-factor.
- Derived unified predictions combining NRQED and all-order $Z\alpha$ calculations.
- Enhanced understanding of electron-correlation effects in light Li-like ions.

## Abstract

We investigate electron-correlation effects in the $g$-factor of the ground state of Li-like ions. Our calculations are performed within the nonrelativistic quantum electrodynamics (NRQED) expansion up to two leading orders in the fine-structure constant $\alpha$, $\alpha^2$ and $\alpha^3$. The dependence of the NRQED results on the nuclear charge number $Z$ is studied and the individual $1/Z$-expansion contributions are identified. Combining the obtained data with the results of the all-order (in $Z\alpha$) calculations performed within the $1/Z$ expansion, we derive the unified theoretical predictions for the $g$-factor of light Li-like ions.