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

Abstract

The electric quadrupole moment of 49 Sc was measured by collinear laser spectroscopy at CERN-ISOLDE to be Q s = −0.159(8) eb, 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 0 f 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.