Isospin diffusion measurement from the direct detection of a Quasi-Projectile remnant

TL;DR

This study investigates isospin diffusion in calcium nuclear collisions at 35 MeV/nucleon, comparing experimental data with theoretical models, revealing insights into neutron-proton equilibration and interaction times.

Contribution

First experimental comparison of QP evaporative and break-up channels in isospin diffusion, and validation of AMD-GEMINI model predictions against data.

Findings

Comparable neutron-proton equilibration in different exit channels.

Experimental data shows less proton and neutron transfer than AMD-GEMINI predictions.

Close interaction times inferred from similar equilibration in both channels.

Abstract

The neutron-proton equilibration process in 48 Ca+ 40 Ca at 35 MeV/nucleon bombarding energy has been experimentally estimated by means of the isospin transport ratio. Experimental data have been collected with a subset of the FAZIA telescope array, which permitted to determine Z and N of detected fragments. For the first time, the QP evaporative channel has been compared with the QP break-up one in a homogeneous and consistent way, pointing out to a comparable n-p equilibration which suggests close interaction time between projectile and target independently of the exit channel. Moreover, in the QP evaporative channel n-p equilibration has been compared with the prediction of the Antisymmetrized Molecular Dynamics (AMD) model coupled to the GEMINI statistical model as an afterburner, showing a larger probability of proton and neutron transfers in the simulation with respect to the experimental data.