Collective excitation in exotic nuclei

Abstract

Low-frequency collective modes of excitation in neutron-rich nuclei are investigated in the framework of the nuclear energy-density functional method. Roles of the neutron pairing correlation and the deformation are studied with a focus on the presence of the loosely bound and resonant neutron orbitals. It is found that the coherent coupling between the pairing and the shape vibrations of neutrons shows up in the low-lying Kφ = 0+ mode. A strong mixing of the isovector and isosclar excitations associated with the neutron-excitation dominance is also found in the low-lying negative-parity excitation mode.