Symmetry energy of fragments produced in multifragmentation

Isospin properties of fragments measured in multifragmentation of 136Xe and 124Xe projectiles in mid-peripheral collisions with a lead target at 1 A GeV were studied within the statistical approach describing the liquid–gas nuclear phase transition. By analyzing the isoscaling phenomenon and the mean N/Z ratio of the fragments with Z = 10–13 we have concluded that the symmetry energy of hot fragments produced in a multifragment environment at subnuclear densities at high temperatures decreases in comparison with cold nuclei.