Variational method for infinite nuclear matter with noncentral forces

Masatoshi Takano, Masami Yamada

    Research output: Contribution to journalArticle

    9 Citations (Scopus)

    Abstract

    Approximate energy expressions are proposed for infinite zero-temperature neutron matter and symmetric nuclear matter by taking into account noncentral forces. They are explicitly expressed as functionals of spin-isospin-dependent radial distribution functions, tensor distribution functions and spin-orbit distribution functions, and can be used conveniently in the variational method. The two-body noncentral cluster terms are fully included in these expressions, while the degree of inclusion of the three-body cluster terms related to noncentral forces is less than that of the purely central three-body terms. The Euler-Lagrange equations are derived from these energy expressions and numerically solved for neutron matter and symmetric nuclear matter. The Hamada-Johnston and AV14 potentials are used as the two-body nuclear force. The results show that the noncentral forces cause the total energy of symmetric nuclear matter to be decreased too much with a saturation density which is too high. Discussion is given as to the reason for this disagreement with experiment, and the long tails of the noncentral distribution functions obtained in the numerical calculations are suspected to be the main reason. Then, an effective theory is proposed by introducing a density-dependent modification of the noncentral part of the energy expression to suppress the long tails of the noncentral distribution functions. With a suitable choice of the value of a parameter included in the modification, the saturation point (both the energy and the density) of symmetric nuclear matter can be reproduced with the Hamada-Johnston potential. Neutron stars are studied by use of this effective theory, and reasonable results are obtained.

    Original languageEnglish
    Pages (from-to)745-771
    Number of pages27
    JournalProgress of Theoretical Physics
    Volume100
    Issue number4
    Publication statusPublished - 1998 Oct

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    distribution functions
    saturation
    neutrons
    Euler-Lagrange equation
    energy
    radial distribution
    functionals
    neutron stars
    flux density
    inclusions
    tensors
    orbits
    causes
    temperature

    ASJC Scopus subject areas

    • Physics and Astronomy(all)

    Cite this

    Variational method for infinite nuclear matter with noncentral forces. / Takano, Masatoshi; Yamada, Masami.

    In: Progress of Theoretical Physics, Vol. 100, No. 4, 10.1998, p. 745-771.

    Research output: Contribution to journalArticle

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