A microscopic study of the dipole giant resonance in fissioning nuclei

Microscopic calculations of the dipole giant resonance in fissioning nuclei give a splitting of the dipole strength into three collective branches, contrary to two branches as predicted by the hydrodynamical model. These collective phenomena have been studied with simplifying separable interactions and sum-rule approaches, and found to be fairly independent of mass number and shell structure. The detailed dependence of excitation energies, dipole strengths and transition densities on the fission coordinate could give rise to interesting phenomena, particularly in electrofission experiments. (Auth.)