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

TL;DR

This paper investigates the decay of hot neutron-rich nuclei, revealing isospin-asymmetric phase transition signals and the influence of secondary emission, with implications for understanding neutron-rich low-density regions in nuclear reactions.

Contribution

It provides new experimental evidence of isospin-asymmetric phase transition signals in hot nuclei and analyzes the effects of secondary emission on thermodynamical observables.

Findings

Observation of isospin-asymmetric phase transition signals.

Thermodynamical observables insensitive to neutron number differences.

Evidence of neutron-rich low-density neck formation.

Abstract

The signal of isospin-asymmetric phase transition in the evolution of the chemical potential was observed for hot quasi-projectiles produced in the reactions 40,48Ca + 27Al confirming an analogous observation in the lighter system 28Si + 112,124Sn. 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 40,48Ca + 27Al, 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.