Spin-Polarized States of Nuclear Matter

The equations of state of spin-polarized nuclear matter and pureneutron matter are studied in the framework of theBrueckner-Hartree-Fock theory including a three-body force. Theenergy per nucleon E_A(δ) calculated in the full range ofspin polarization δ=(ρ_↑-ρ_↓)/ρ for symmetric nuclear matter and pure neutron matter fulfills a parabolic law.In both the cases the spin-symmetry energy is calculated as afunction of the baryonic density along with the related quantities such as the magnetic susceptibility and the Landau parameter G₀. The main effect of the three-body force is to strongly reduce the degenerate Fermi gas magnetic susceptibilityeven more than the value with only two-body force. The equationof state is monotonically increasing with the density for allspin-aligned configurations studied here so that no any signatureis found for a spontaneous transition toa ferromagnetic state.