Self-consistent continuum random-phase approximation with finite-range interactions for charge-exchange excitations

Abstract

The formalism of the continuum random-phase approximation theory which treats, without ap- proximations, the continuum part of the single-particle spectrum, is extended to describe charge- exchange excitations. Our approach is self-consistent, meaning that we use a unique, finite-range, interaction in the Hartree-Fock calculations which generate the single-particle basis and in the con- tinuum random-phase approximation which describes the excitation. We study excitations induced by the Fermi, Gamow-Teller and spin-dipole operators in doubly magic nuclei by using four Gogny- like finite-range interactions, two of them containing tensor forces. We focus our attention on the importance of the correct treatment of the continuum configuration space and on the effects of the tensor terms of the force.1