Isospin nonequilibrium in heavy-ion collisions at intermediate energies Academic Article uri icon

abstract

  • The equilibration of the isospin degree of freedom in intermediate energy heavy-ion collisions was studied using an isospin-dependent BUU model. It is found that there exists a transition from the isospin equilibration at low energies to nonequilibration at high energies as the beam energy varies across the Fermi energy in central, asymmetric, heavy-ion collisions. At beam energies around 55 MeV/nucleon the composite system is in almost complete thermal equilibrium but isospin nonequilibrium breaks up into two primary hot residues with NZ ratios closely related to those of the target and projectile, respectively. The decay of these forward-backward moving residues results in the strong isospin asymmetry in space and the dependence of the isotopic composition of fragments on the NZ ratios of the target and projectile. These features are in good agreement with those found recently in experiments at NSCL/MSU and TAMU; implications of these findings are discussed. © 1995 The American Physical Society.

author list (cited authors)

  • Li, B., & Yennello, S. J.

citation count

  • 50

publication date

  • October 1995