Fine and hyperfine splitting of the 2P state in Li and Be$^+$

TL;DR

This paper presents precise theoretical calculations of the fine and hyperfine splitting in the 2P state of lithium and beryllium ions, comparing results with experiments to improve nuclear magnetic moment measurements.

Contribution

It introduces highly accurate calculations including relativistic and QED effects using Hylleraas basis sets, advancing the understanding of hyperfine interactions in these ions.

Findings

Theoretical predictions align closely with experimental data.

Mixing of P_{1/2} and P_{3/2} states significantly affects hyperfine splitting.

Eliminating nuclear structure effects is essential for accurate nuclear magnetic moment determination.

Abstract

Accurate calculations of the fine and hyperfine splitting of the 2P state in Li and Be$^+$ isotopes using the explicitly correlated Hylleraas basis set are presented. Theoretical predictions including the mixing of $P_{1/2}$ and $P_{3/2}$ states, relativistic and quantum electrodynamics effects on hyperfine interactions, are compared with experimental values. It is concluded that precise spectroscopic determination of the nuclear magnetic moments requires elimination of nuclear structure effects by combining measurements for two different states.