Abstract
It is shown that the experimentally observed decrease of nuclear symmetry energy with increasing centrality or excitation energy in isotopic scaling analyses of heavy-ion reactions can be well understood analytically within a degenerate Fermi gas model. The evolution of the symmetry energy is found to be mainly due to the variation in the freeze-out density rather than temperature. The isoscaling analyses are useful for probing the interaction part of the nuclear symmetry energy, provided that both the freeze-out temperature and density of the fragments can be inferred simultaneously from the experiments.
- Received 29 April 2006
DOI:https://doi.org/10.1103/PhysRevC.74.034610
©2006 American Physical Society