Pure Neutron Matter Constraints and Nuclear Symmetry Energy

In this review, we will discuss the results of our recent work [1] to study the general optimization of the pure isovector parameters of the popular relativistic mean-field (RMF) and Skyrme-Hartree-Fock (SHF) nuclear energy-density functionals (EDFs), using constraints on the pure neutron matter (PNM) equation of state (EoS) from recent ab initio calculations. By using RMF and SHF parameterizations that give equivalent predictions for ground-state properties of doubly magic nuclei and properties of symmetric nuclear matter (SNM) and PNM, we found that such optimization leads to broadly consistent symmetry energy J and its slope parameter L at saturation density within a tight range of α(J) < 2 MeV and α(L) < 6 MeV. We demonstrate that a clear model dependence shows up (a) in the curvature parameter of the symmetry energy K_sym, (b) the symmetry energy at supra-saturation densities, and (c) the radius of neutron stars.