Density and Symmetric Potential Dependences of Isoscaling Behaviour in the Lattice Gas Model

Abstract

Isoscaling behavior of the statistical emission fragments from the equilibrated sources with Z = 30 and N = 30, 33, 36 and 39, resepectively, is investigated in the framework of isospin dependent lattice gas model. The dependences of isoscaling parameters α on source isospin asymmetry, temperature and freeze-out density are studied and the "symmetry energy" is deduced from isoscaling parameters. Results show that "symmetry energy" Csym is insensitive to the change of temperature but follows the power-law dependence on the freeze-out density ρ. The later gives Csym = 30(ρ/ρ0) 0.62 if the suitable asymmetric nucleon-nucleon potential is taken. The effect of strength of asymmetry of nucleon-nucleon interaction potential on the density dependence of the "symmetry energy" is dicussed.