Effect of entrance-channel asymmetry on the isospin dependence of nucleon emission in heavy ion collisions
- Received Date: 2007-07-24
- Accepted Date: 2008-03-27
- Available Online: 2008-07-05
Using the isospin- and momentum-dependent hadronic transport model IBUU04, we have investigated the influence of the entrance-channel isospin asymmetry on the sensitivity of the pre-equilibrium neutron/proton ratio to symmetry energy in central heavy-ion collisions induced by high-energy radioactive beams. Our analysis and discussion are based on the dynamical simulations of the three
isotopic reaction systems 132Sn+124Sn, 124Sn+112Sn and 112Sn+112Sn which are of the same total proton number but different isospin asymmetry. We find that the kinetic-energy distributions of the pre-equilibrium neutron/proton ratio are quite sensitive to the density-dependence of symmetry energy at incident
beam energy E/A=400MeV, and the sensitivity increases as the isospin asymmetry of the reaction system increases.