Hyperfine structure of the metastable 3P2 state of alkaline earth atoms as an accurate probe of nuclear magnetic octupole moments

TL;DR

This paper investigates how hyperfine structure measurements of metastable states in alkaline earth atoms can be used to detect and analyze nuclear magnetic octupole moments, providing a new probe for nuclear properties.

Contribution

The study combines relativistic atomic structure calculations and nuclear shell model analysis to evaluate the influence of nuclear octupole moments on hyperfine structures.

Findings

Sensitivity of HFS measurements in $^{87}$Sr can detect nuclear octupole effects at kHz precision.

Analysis extends to $^{9}$Be, $^{25}$Mg, and $^{43}$Ca, showing broader applicability.

Higher nuclear moments significantly affect hyperfine structure, enabling nuclear property probing.

Abstract

Measuring the hyperfine structure (HFS) of long-lived $^3P_2$ states of divalent atoms may offer the opportunity of extracting relatively unexplored nuclear magnetic octupole and electric hexadecapole moments. Here, using relativistic many-body methods of atomic structure and the nuclear shell model, we evaluate the effect of these higher nuclear moments on the hyperfine structure. We find that the sensitivity of HFS interval measurements in $^{87}$Sr needed to reveal the perturbation caused by the nuclear octupole moment is on the order of kHz. Results of similar analyses for $^{9}$Be, $^{25}$Mg, and $^{43}$Ca are also reported.