Forma, Vol. 7 (No. 1), pp. 67-76, 1992
Original Paper

Irreversibility in Nuclear Physics

Toshitake Kohmura

Institute of Physics, University of Tsukuba, Ibaraki 305, Japan

(Received August 24, 1991; Accepted November 1, 1991)

Keywords: Systematization of Matter, Biological Growth, Nuclear Fusion, Mean-Field Approximation, Nucleon-Nucleon Scattering

Abstract. Two kinds of irreversible processes are discussed, i.e., desystematization and systematization. The systematization of matter, the evolution of the universe, for example, takes place in a subsystem of a system which is desystematized in accordance with the law of entropy increase. When we are concerned with biological growth, a systematizing process, we should include in the biological system the sun which supplies the energy to it. The sun produces the photo-energies in nuclear fusion reactions, which are themselves irreversible processes. Nuclear fusion reactions have the two-sided features of desystematization and systematization and are the most suitable objects to investigate systematizing processes of a quantum system. In order to describe the two-sided features of nuclear fusion, we propose to generalize the mean-field approximation taking into account the nucleon-nucleon scattering terms.