Collective excitations in superfluid nuclei with finite-range interactions

For the first time, the Gogny force, a finite range interaction, is used to calculate self-consistently low-lying vibrational states and giant resonances in superfluid nuclei. The theoretical framework is based on the quasiparticle random phase approximation, starting from ground state wave functions obtained according to the Hartree-Fock-Bogoliubov theory. We study the isotopic chains of oxygen, nickel and tin isotopes, extending from the valley of stability towards the drip lines. It is found that the comparison with the experimental data is not very satisfactory. A critical analysis is attempted