Multinucleon transfer dynamics in heavy-ion collisions near Coulomb barrier energies

TL;DR

This paper models multinucleon transfer reactions near Coulomb barrier energies using a multistep DNS-based approach, revealing fragment production along the stability line and significant isospin relaxation effects.

Contribution

It introduces a comprehensive DNS-based model combining analytical, diffusion, and statistical methods to simulate multinucleon transfer dynamics in heavy-ion collisions.

Findings

Fragments are mainly produced along the beta-stability line.

Isospin relaxation plays a significant role in fragment formation.

The incident energy influences the yield of heavy target-like fragments.

Abstract

The multinucleon transfer reactions near barrier energies has been investigated with a multistep model based on the dinuclear system (DNS) concept, in which the capture of two colliding nuclei, the transfer dynamics and the de-excitation process of primary fragments are described by the analytical formula, the diffusion theory and the statistical model, respectively. The nucleon transfer takes place after forming the DNS and is coupled to the dissipation of relative motion energy and angular momentum by solving a set of microscopically derived master equations within the potential energy surface. Specific reactions of $^{40,48}$Ca+$^{124}$Sn, $^{40}$Ca ($^{40}$Ar, $^{58}$Ni)+$^{232}$Th, $^{40}$Ca ($^{58}$Ni)+$^{238}$U and $^{40,48}$Ca ($^{58}$Ni) +$^{248}$Cm near barrier energies are investigated. It is found that the fragments are produced by the multinucleon transfer reactions with the maximal yields along the $\beta$-stability line. The isospin relaxation is particularly significant in the process of fragment formation. The incident energy dependence of heavy target-like fragments in the reaction of $^{58}$Ni+$^{248}$Cm is analyzed thoroughly.