Equation of State of Spin-Polarized Nuclear Matter

Abstract：

Within the spin-dependent Brueckner-Hartree-Fock framework, the equation of state of the spin-polarized nuclear matter has been investigated by adopting the realistic nucleon-nucleon interaction AV₁₈ supplemented with a microscopic three-body force. The related physical quantities such as the Landau parameters G₀ in spin channel and G′₀ in spin-isospin channel, have been calculated. The three-body force effects have been studied and stressed with a special attention. It is shown that in the Brueckner-Hartree-Fock framework the predicted energy per particle of spin-polarized nuclear matter versus the neutron and proton spin-polarization parameters fulfills a quadratic law in the whole range of spin-polarization. At the empirical saturation density, the calculated Landau parameter G′₀ is 1.22 and 1.28 respectively for the two-cases with and without including the three-body force, both are in agreement with its experimental value. Both the Landau parameters G₀ and G′₀ are positive in the density region up to ρ=0.5fm^－3 and increase monotonically as increasing density so that no any evidence is found for a spontaneous transition to a ferromagnetic state in nuclear matter. The three-body force effect is to strongly increase the Landau parameters G₀ and G′₀ at high densities, making the nuclear matter at high densities more stable against spin and spin-isospin fluctuations. The obtained Landau parameters G₀ and G′₀ together with their density dependences may serve as constraints on the spin-spin parts and spin-isospin dependent parts of the phenomenological Skyrme and Skyrme-like interactions.