Magnetic excitations in nuclei with neutron excess

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.

Comments: 18 pages, 12 figures, 2 tables, accepted for publication in Physical Review C