Ground-State Electromagnetic Moments of Calcium Isotopes

Abstract

High-resolution bunched-beam collinear laser spectroscopy was used to measure the optical hyperfine spectra of the ${}^{43-51}$Ca isotopes. The ground state magnetic moments of ${}^{49,51}$Ca and quadrupole moments of ${}^{47,49,51}$Ca were measured for the first time, and the ${}^{51}$Ca ground state spin $I=3/2$ was determined in a model-independent way. Our results provide a critical test of modern nuclear theories based on shell-model calculations using phenomenological as well as microscopic interactions. The results for the neutron-rich isotopes are in excellent agreement with predictions using interactions derived from chiral effective field theory including three-nucleon forces, while lighter isotopes illustrate the presence of particle-hole excitations of the ${}^{40}$Ca core in their ground state.

Comments: Accepted as a Rapid Communication in Physical Review C