Collectivity of the low-lying dipole strength in relativistic random phase approximation Original Research Article

The relativistic random phase approximation is applied in the analysis of the evolution of the isovector dipole response in nuclei with a large neutron excess. The self-consistent framework of relativistic mean-field theory, which has been very successfully applied in the description of ground-state properties of nuclei far from the valley of β-stability, is extended to study the possible onset of low-energy collective isovector dipole modes in nuclei with extreme isospin values.