Theoretical approaches and experimental evidence for liquid-vapor phase transitions in nuclei

Abstract

Abstract. The leptodermous approximation is applied to nuclear systems for T ¢ 0. The introduction of surface corrections leads to anomalous caloric curves and to negative heat capacities in the liquid-gas coexistence region. Clusterization in the vapor is described by associating surface energy to clusters according to Fisher's formula. The three-dimensional Ising model, a leptodermous system par excellence, does obey rigorously Fisher's scaling up to the critical point. Multifragmentation data from several experiments including the ISiS and EOS Collaborations, as well as compound nucleus fragment emission at much lower energy follow the same scaling, thus providing the strongest evidence yet of liquid-vapor coexistence.

Tracing the evolution of temperature in near Fermi energy heavy ion collisions

“…This could somewhat mitigate arguments that the concept of establishment of a liquid gas equilibrium is not tenable in a nuclear collision as there is no container to constrain the gas. Of course, more recently it has also been argued, on the basis of detailed balance, that the actual physical equilibrium is not necessary [36].…”