Isospin Diffusion in Heavy Ion Reactions

TL;DR

This study investigates isospin diffusion in heavy ion collisions at 50 MeV per nucleon, revealing incomplete isospin equilibrium and enabling exploration of the nuclear symmetry energy's density dependence.

Contribution

It introduces a method using isoscaling and scaled ratios to assess isospin transport and the density dependence of the symmetry energy in heavy ion reactions.

Findings

Isospin diffusion does not reach equilibrium in the studied collisions.

Scaled ratios effectively probe the density dependence of the symmetry energy.

Experimental data align with theoretical models of the nuclear equation of state.

Abstract

Using symmetric 112Sn+112Sn, 124Sn+124Sn collisions as references, we probe isospin diffusion in peripheral asymmetric 112Sn+124Sn, 124Sn+112Sn systems at incident energy of E/A=50 MeV. Isoscaling analyses imply that the quasi-projectile and quasi-target in these collisions do not achieve isospin equilibrium, permitting an assessment of the isospin transport rates. We find that comparisons between isospin sensitive experimental and theoretical observables, using suitably chosen scaled ratios, permit investigation of the density dependence of the asymmetry term of the nuclear equation of state.