Properties of hot asymmetric nuclear matter

Thermodynamic properties of asymmetric nuclear matter are studied by the temperature-dependent Hartree-Fock theory with the effective interaction. The asymmetry- and the temperature-dependences of the bulk quantities such as the internal energy, the entropy, the pressure and the specific heat as well as the single-particle quantities such as the effective mass and the potential depth are analyzed. In the effective interaction, a phenomenological term simulating the three-body interaction is introduced to assure the empirical saturation property and three cases specified by the incompressibility k=200, 250 and 300 MeV are considered. It is argued how the liquid-gas phase transition depends on k relevant to the stiffness of nuclear equation of state. Also, the neutron star equation of state for three cases is discussed in relation to the causality condition and the neutron star mass 1.44 (solar mass) of PSR1913+16. Finally a simplified treatment of the phenomenological term in the energy calculation at finite temperature is proposed. (author)