LOWEST-ORDER CONSTRAINED VARIATIONAL CALCULATION FOR HOT ASYMMETRIC NUCLEAR-MATTER

The method of lowest-order constrained variational that reasonably pre dicts the nuclear matter saturation data is used to calculate the equa tion of state of asymmetric nuclear matter at finite temperature. The Reid soft-core potential with and without the N-Delta interaction, whi ch fits N-N scattering data, is taken as the nuclear Hamiltonian. The calculation is performed for a wide range of density, asymmetry parame ter and nuclear temperature, which are of interest in heavy-ion collis ions and astrophysics. Beside spin, isospin, total angular momentum an d density dependence of the correlation functions, they are also arran ged to depend on the temperature and asymmetry parameter of the system . The free energy, pressure, effective mass etc of asymmetric nuclear matter are calculated. It is shown that while the calculated symmetry coefficient defined in the semi-empirical mass formula is roughly cons tant and is near its empirical value at zero temperature, it depends o n the proton-to-neutron ratio at finite temperature. Finally, the depe ndence of the liquid-vapour phase transition, as well as the effective mass dependence on the temperature and asymmetry parameter, is invest igated.