Variational study for the equation of state of asymmetric nuclear matter at finite temperatures

H. Togashi, Masatoshi Takano

    Research output: Contribution to journalArticle

    21 Citations (Scopus)

    Abstract

    An equation of state (EOS) for uniform asymmetric nuclear matter (ANM) is constructed at zero and finite temperatures by the variational method starting from the nuclear Hamiltonian that is composed of the Argonne v18 and Urbana IX potentials. At zero temperature, the two-body energy is calculated with the Jastrow wave function in the two-body cluster approximation which is supplemented by Mayer's condition and the healing-distance condition so as to reproduce the result by Akmal, Pandharipande and Ravenhall. The energy caused by the three-body force is treated somewhat phenomenologically so that the total energy reproduces the empirical saturation conditions. The masses and radii of neutron stars obtained with the EOS are consistent with recent observational data. At finite temperatures, thermodynamic quantities such as free energy, internal energy, entropy, pressure and chemical potentials are calculated with an extension of the method by Schmidt and Pandharipande. The validity of the frozen-correlation approximation employed in this work is confirmed as compared with the result of the fully minimized calculation. The quadratic proton-fraction-dependence of the energy of ANM is confirmed at zero temperature, whereas the free energy of ANM deviates from the quadratic proton-fraction-dependence markedly at finite temperatures. The obtained EOS of ANM will be an important ingredient of a new nuclear EOS for supernova numerical simulations.

    Original languageEnglish
    Pages (from-to)53-73
    Number of pages21
    JournalNuclear Physics A
    Volume902
    DOIs
    Publication statusPublished - 2013 Mar 5

    Fingerprint

    equations of state
    free energy
    temperature
    protons
    energy
    healing
    internal energy
    approximation
    ingredients
    neutron stars
    supernovae
    wave functions
    entropy
    saturation
    thermodynamics
    radii
    simulation

    Keywords

    • Neutron stars
    • Nuclear EOS
    • Nuclear matter
    • Supernovae
    • Variational method

    ASJC Scopus subject areas

    • Nuclear and High Energy Physics

    Cite this

    Variational study for the equation of state of asymmetric nuclear matter at finite temperatures. / Togashi, H.; Takano, Masatoshi.

    In: Nuclear Physics A, Vol. 902, 05.03.2013, p. 53-73.

    Research output: Contribution to journalArticle

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