Statistical and dynamical aspects in the decay of hot neutron-rich nuclei

The signal of isospin-asymmetric phase transition in the evolution of the chemical potential was observed for hot quasi-projectiles produced in the reactions Ca + Al confirming an analogous observation in the lighter system Si + Sn [1]. With increasing mass, the properties of hot quasi-projectiles become increasingly influenced by the secondary emission. Thermodynamical observables exhibit no sensitivity to the different number of missing neutrons in the two reactions Ca + Al, thus providing a signal of dynamical emission of neutrons, which can be related to formation of a very neutron-rich low-density region ( neck ) between the projectile and target.