Isospin nonequilibrium in heavy-ion collisions at intermediate energies

Journal Article · Sun Oct 01 04:00:00 EDT 1995 · Physical Review, C

DOI:https://doi.org/10.1103/PhysRevC.52.R1746· OSTI ID:118469

Li, B; Yennello, S J ^[1]

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1. Cyclotron Institute and Department of Physics, Texas A&M University, College Station, Texas 77843 (United States)

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 {ital N}/{ital Z} 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 {ital N}/{ital Z} 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.

• DOE Contract Number: FG05-86ER40256
• OSTI ID: 118469
• Journal Information: Physical Review, C, Journal Name: Physical Review, C Journal Issue: 4 Vol. 52; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ASYMMETRY
DEGREES OF FREEDOM
EQUILIBRIUM
HEAVY ION REACTIONS
ISOSPIN
NUCLEAR FRAGMENTS