A computational model for the investigation of nuclear many-body effects : from reaction dynamics to phase transitions

A Hamiltonian model is advanced which provides a computationally efficient means of investigating nuclear many-body effects. The Hamiltonian includes both Coulomb and isospin dependent terms, and incorporates antisymmetrization effects though a momentum-dependent potential. Unlike many other classical and semiclassical models, the nuclei of this 2 simulation have a well-defined ground state with a nonvanishing . The ground state nuclei produced by the model compare favorably in energy and RMS radius with the experimentally observed values. The model provides a means to investigate the time scales associated with various reaction mechanisms found in heavy ion collisions. In particular, the thermalization in heavy ion collisions is investigated by examining the kinetic energy distributions and excited state populations predicted by the model. It is found that the apparent temperature scales obtained from these distributions are different, and their predicted magnitudes are in agreement with experiment. The model is also used to explore the phase diagram of infinite nuclear matter. In the phase diagram study it is found that finite size effects for systems of masses typical of heavy ion collision are sufficiently large to prevent one from making any clear association of the fragmentation process with the nuclear phase diagram.