Landau parameters for asymmetric nuclear matter with a strong magnetic field

Abstract

The Landau Fermi-liquid parameters are calculated for charge-neutral asymmetric nuclear matter in beta equilibrium at zero temperature in the presence of a very strong magnetic field with relativistic mean-field models. Due to the isospin structure of the system, with different populations of protons and neutrons and spin alignment to the field, we find nonvanishing Landau mixing parameters. The existence of quantized Landau levels for the charged sector has some impact on the Landau parameters with the presence of discretized features in those involving the proton sector. Using the Fermi-liquid formalism singlet and triplet excited quasiparticle states are analyzed, and we find that in-medium effects and magnetic fields are competing; however, the former are more important in the interaction energy range considered. It is found that for magnetic field strengths ${\mathrm{log}}_{10}B(G)\ensuremath{\le}17$ the relatively low polarization of the system produces mild changes in the generalized Landau parameters with respect to the unmagnetized case, while for larger strengths there is a resolution of the degeneracy of the interaction energies of quasiparticles in the system. As an application we calculate the incompressibility and first sound velocities to illustrate how this formalism can be used to obtain physical information from the system.