Isospin diffusion measurement from the direct detection of a quasiprojectile remnant

Abstract

The neutron-proton (n-p) equilibration process in $^{48}\mathrm{Ca}+^{40}\mathrm{Ca}$ at 35 MeV/nucleon bombarding energy is experimentally estimated by means of the isospin transport ratio. Experimental data are collected with a subset of the FAZIA telescope array, which permits us to determine the $Z$ and $N$ of detected fragments. For the first time, the quasiprojectile (QP) evaporative channel is compared with the QP breakup one in a homogeneous and consistent way, pointing to comparable n-p equilibration, which suggests a close interaction time between projectile and target independently of the exit channel. Moreover, in the QP evaporative channel n-p equilibration is compared with the prediction of the antisymmetrized molecular dynamics model coupled with the Gemini statistical model as an afterburner, showing a higher probability of proton and neutron transfers in the simulation with respect to the experimental data.