Dense nuclear matter and symmetry energy in strong magnetic fields

TL;DR

This paper investigates how strong magnetic fields influence nuclear matter properties, including symmetry energy, composition, and spin polarization, using relativistic mean field models with anomalous magnetic moments.

Contribution

It introduces a detailed analysis of nuclear matter under strong magnetic fields, incorporating AMM and nonlinear couplings, revealing the magnetic enhancement of symmetry energy and its effects.

Findings

Symmetry energy increases with magnetic field strength.

Magnetic fields significantly alter chemical composition and proton polarization.

Parabolic isospin dependence remains valid below 10^5 B_c^e.

Abstract

The properties of nuclear matter in the presence of a strong magnetic field, including the density-dependent symmetry energy, the chemical composition and spin polarizations, are investigated in the framework of the relativistic mean field models FSU-Gold. The anomalous magnetic moments (AMM) of the particles and the nonlinear isoscalar-isovector coupling are included. It is found that the parabolic isospin-dependence of the energy per nucleon of asymmetric nuclear matter remains valid for values of the magnetic field below $10^{5}B_{c}^{e}$, $B_{c}^{e}=4.414\times10^{13}$G being the electron critical field. Accordingly, the symmetry energy can be obtained by the difference of the energy per nucleon in pure neutron matter and that in symmetric matter. The symmetry energy, which is enhanced by the presence of the magnetic field, significantly affects the chemical composition and the proton polarization. The effects of the AMM of each component on the energy per nucleon, symmetry energy, chemical composition and spin polarization are discussed in detail.