Interaction between deformed nuclei at finite temperature

Within a complex free-energy density functional, derived from a realistic nucleon-nucleon interaction, the dependence on temperature of the real and imaginary parts of the free interaction energy of the deformed system U-U is investigated. It is found that the potentials strongly depend on orientations and temperature, where at zero orientation angle (beta=0 degrees) the potentials acquire repulsion, with increasing temperature, up to a critical value (T similar to 3 MeV), where shell effects become very small; beyond this value the potentials inverse this behavior. For large values of beta the potentials become more and more attractive with increasing temperature. At much higher excitation (T similar to 5 MeV) the potentials become insensitive to orientations, due to the disappearance of shell corrections. The dependence of the relative momentum per nucleon on the internuclear distance is also investigated.