Electromagnetic moments of scandium isotopes and $N=28$ isotones in the distinctive $0f_{7/2}$ orbit

TL;DR

This study measures electromagnetic moments of scandium isotopes and $N=28$ isotones, providing insights into nucleon correlations and benchmarking shell-model and ab-initio calculations in the $0f_{7/2}$ orbit.

Contribution

It offers high-precision measurements of electromagnetic moments and compares them with advanced theoretical models, enhancing understanding of nuclear structure in this region.

Findings

Precise quadrupole moment of $^{49}$Sc measured.

Electromagnetic moments show sensitivity to nucleon-nucleon correlations.

Benchmark data for shell-model and ab-initio calculations.

Abstract

The electric quadrupole moment of $^{49}$Sc was measured by collinear laser spectroscopy at CERN-ISOLDE to be $Q_{\rm s}=-0.159(8)$ $e$b, and a nearly tenfold improvement in precision was reached for the electromagnetic moments of $^{47,49}$Sc. The single-particle behavior and nucleon-nucleon correlations are investigated with the electromagnetic moments of $Z=21$ isotopes and $N=28$ isotones as valence neutrons and protons fill the distinctive $0f_{7/2}$ orbit, respectively, located between magic numbers, 20 and 28. The experimental data are interpreted with shell-model calculations using an effective interaction, and ab-initio valence-space in-medium similarity renormalization group calculations based on chiral interactions. These results highlight the sensitivity of nuclear electromagnetic moments to different types of nucleon-nucleon correlations, and establish an important benchmark for further developments of theoretical calculations.