Electric quadrupole and magnetic dipole moments of odd nuclei near the magic ones in a self-consistent approach

TL;DR

This paper introduces a self-consistent model combining Hartree-Fock and Random Phase Approximation to accurately predict electric quadrupole and magnetic dipole moments of odd nuclei near magic numbers, improving upon simpler models.

Contribution

The model uniquely integrates core polarization effects with a consistent finite-range interaction, providing parameter-free predictions comparable to phenomenological approaches.

Findings

Improved agreement with experimental moments over independent particle models.

Consistent results across multiple isotopic chains.

Comparable accuracy to phenomenological and perturbative methods.

Abstract

We present a model which describes the properties of odd-even nuclei with one nucleon more, or less, with respect to the magic number. In addition to the effects related to the unpaired nucleon, we consider those produced by the excitation of the closed shell core. By using a single particle basis generated with Hartree-Fock calculations, we describe the polarization of the doubly magic-core with Random Phase Approximation collective wave functions. In every step of the calculation, and for all the nuclei considered, we use the same finite-range nucleon-nucleon interaction. We apply our model to the evaluation of electric quadrupole and magnetic dipole moments of odd-even nuclei around oxygen, calcium, zirconium, tin and lead isotopes. Our Random Phase Approximation description of the polarization of the core improves the agreement with experimental data with respect to the predictions of the independent particle model. We compare our results with those obtained in first-order perturbation theory, with those produced by Hartree-Fock-Bogolioubov calculations and with those generated within the Landau-Migdal theory of finite Fermi systems. The results of our universal, self-consistent, and parameter free approach have the same quality of those obtained with phenomenological approaches where the various terms of the nucleon-nucleon interaction are adapted to reproduce some specific experimental data. A critical discussion on the validity of the model is presented.