Dipolar degrees of freedom and Isospin equilibration processes in Heavy Ion collisions

TL;DR

This study investigates isospin equilibration in heavy ion collisions at Fermi energies using dipole observables, providing insights into the isovectorial effective interaction through experimental data and dynamical model comparisons.

Contribution

It introduces a novel method based on dipole observables to probe the dynamical stage of isospin equilibration in heavy ion collisions.

Findings

Dipole observable is sensitive to the isospin equilibration process.

Experimental data supports the effectiveness of the dipole-based method.

Comparison with models provides information on the isovectorial effective interaction.

Abstract

Background: In heavy ion collision at the Fermi energies Isospin equilibration processes occur- ring when nuclei with different charge/mass asymmetries interacts have been investigated to get information on the nucleon-nucleon Iso-vectorial effective interaction. Purpose: In this paper, for the system 48Ca +27 Al at 40 MeV/nucleon, we investigate on this process by means of an observable tightly linked to isospin equilibration processes and sensitive in exclusive way to the dynamical stage of the collision. From the comparison with dynamical model calculations we want also to obtain information on the Iso-vectorial effective microscopic interaction. Method: The average time derivative of the total dipole associated to the relative motion of all emitted charged particles and fragments has been determined from the measured charges and velocities by using the 4? multi-detector CHIMERA. The average has been determined for semi- peripheral collisions and for different charges Zb of the biggest produced fragment. Experimental evidences collected for the systems 27Al+48Ca and 27Al+40Ca at 40 MeV/nucleon used to support this novel method of investigation are also discussed.