In the 80's were discovered the giant resonances built on the compound nucleus (hot nucleus). Classically it is natural to consider the vibrations of a hot drop of nuclear liquid. However a quantum description of such states is difficult. The microscopic theories like the RPA describe such state as a coherent single-particle excitations.
The properties of the hot giant resonances are not yet understood. Of particular interest are the evolution of the width and the observed disappearance of this mode above a given temperature (about 5 MeV for tin nuclei). These features have been widely investigated by our group partly in collaboration with the experimental groups of Orsay, Saclay and Catania.