New kind of phase transition in hot nuclei

The thermodynamic properties of finite nuclei at excitation energies between 10 MeV and 2 GeV are quite distinct from those of ordinary many-body systems. Due to the small size and the high charge the accessible phase space is dominated by the interplay of surface and long-range Coulomb energies. In a microcanonical Monte Carlo simulation of the decay channels of ¹³¹Xe phase transitions are found which are characterized by the opening of pseudo-fission or cracking modes. These can be identified with anomalies found in recent heavy-ion and high-energetic proton-induced reactions. They, especially the first one, have nothing to do with the liquid—gas transition.