Relaxation of some fermion nonequilibrium momentum distributions

Journal Article · Mon Feb 01 00:00:00 EST 1982 · Phys. Rev. C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.25.1018· OSTI ID:5783084

Toepffer, C; Wong, C

We study the time evolution of momentum distribution for an infinite, dilute, and spatially homogeneous system of fermions by solving the Uehling-Uhlenbeck equation. The initial nonequilibrium distributions examined are taken to be (i) a Fermi sphere with an outer spherical shell, and (ii) a Fermi bisphere. It is found that the entropy of the system approaches its equilibrium value in a nearly exponential manner. Such a behavior allows an extraction of the relaxation times. The relaxation times decrease with increasing size of the perturbation and depend on the shape of the perturbation. Deviations from equilibrium in the initial momentum distribution persist into the late stages of the relaxation process.

• Research Organization: Department of Physics and Nuclear Physics Research Unit, University of Witwaterstrand, Johannesburg, South Africa
• OSTI ID: 5783084
• Journal Information: Phys. Rev. C; (United States), Vol. 25:2
• Country of Publication: United States
• Language: English

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73 NUCLEAR PHYSICS AND RADIATION PHYSICS
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MOMENTUM TRANSFER
RELAXATION
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HARTREE-FOCK METHOD
KINETIC EQUATIONS
MANY-BODY PROBLEM
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TIME DEPENDENCE
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657002 - Theoretical & Mathematical Physics- Classical & Quantum Mechanics