LOCV calculation for Beta-stable matter at finite temperature

The method of lowest-order constrained variational, which predicts reasonably the nuclear matter semi-empirical data is used to calculate the equation of state of beta-stable matter at finite temperature. The Reid soft-core with and without the N-$\Delta$ interactions which fits the N-N scattering data as well as the $UV_{14}$ potential plus the three-nucleon interaction are considered in the nuclear many-body Hamiltonian. The electron and muon are treated relativistically in the total Hamiltonian at given temperature, to make the fluid electrically neutral and stable against beta decay. The calculation is performed for a wide range of baryon density and temperature which are of interest in the astrophysics. The free energy, entropy, proton abundance, etc. of nuclear beta-stable matter are calculated. It is shown that by increasing the temperature, the maximum proton abundance is pushed to the lower density while the maximum itself increases as we increase the temperature. The proton fraction is not enough to see any gas-liquid phase transition. Finally we get an overall agreement with other many-body techniques, which are available only at zero temperature.Comment: LaTex, 20 page

Spin-spin correlation effect on the thermodynamic properties of the polarized liquid 3 He at finite temperature

We have used the lowest order constrained variational (LOCV) method to calculate some thermodynamic properties of the polarized liquid 3He at finite temperature with the spin-dependent correlation function. For each value of the temperature and density we have shown that the main contribution to the potential energy comes from the spin-triplet state. For the polarized liquid 3He, we have seen that the differences between the thermodynamic properties of the spin-dependent and the spin-independent cases decrease by increasing both polarization and temperature. For all relevant temperatures and densities, our results do not show any ferromagnetic phase transition

Hot magnetized nuclear matter: Thermodynamic and saturation properties

We have used a realistic nuclear potential, AV18, and a many body technique, the lowest order constraint variational (LOCV) approach, to calculate the properties of hot magnetized nuclear matter. By investigating the free energy, spin polarization parameter, and symmetry energy, we have studied the temperature and magnetic field dependence of the saturation properties of magnetized nuclear matter. In addition, we have calculated the equation of state of magnetized nuclear matter at different temperatures and magnetic fields. It was found that the flashing temperature of nuclear matter decreases by increasing the magnetic field. In addition, we have studied the effect of the magnetic field on liquid gas phase transition of nuclear matter. The liquid gas coexistence curves, the order parameter of the liquid gas phase transition, and the properties of critical point at different magnetic fields have been calculated.Comment: 30 pages, 13 figures, 2 tables. Accepted for publication in European Physical Journal