Magnetic excitations in nuclei with neutron excess

TL;DR

This paper investigates magnetic excitations in various oxygen and calcium isotopes using self-consistent RPA with Gogny interactions, highlighting the evolution of resonances and the importance of continuum and tensor effects.

Contribution

It provides a detailed analysis of magnetic modes in neutron-rich nuclei using advanced self-consistent RPA methods with tensor-inclusive Gogny interactions.

Findings

Magnetic resonances evolve with neutron number.

Collective effects are significant in excitations.

Continuum and tensor forces are crucial for accurate modeling.

Abstract

The excitation of the $1^+$, $2^-$ and $3^+$ modes in $^{16}$O, $^{22}$O, $^{24}$O, $^{28}$O, $^{40}$Ca, $^{48}$Ca, $^{52}$Ca and $^{60}$Ca nuclei is studied with self-consistent random phase approximation calculations. Finite-range interactions of Gogny type, containing also tensor-isospin terms, are used. We analyze the evolution of the magnetic resonances with the increasing number of neutrons, the relevance of collective effects, the need of a correct treatment of the continuum and the role of the tensor force.