The Equation of State of Nuclear Matter: From Finite Nuclei to Neutron Stars

Background.We investigate possible correlations between neutron star observables and properties of atomic nuclei. In particular, we explore how the tidal deformability of a 1.4 solar mass neutron star, M-1.4, and the neutron-skin thickness of48Ca and208Pb are related to the stellar radius and the stiffness of the symmetry energy.Methods.We examine a large set of nuclear equations of state based on phenomenological models (Skyrme, NLWM, DDM) andab initiotheoretical methods (BBG, Dirac-Brueckner, Variational, Quantum Monte Carlo).Results:We find strong correlations between tidal deformability and NS radius, whereas a weaker correlation does exist with the stiffness of the symmetry energy. Regarding the neutron-skin thickness, weak correlations appear both with the stiffness of the symmetry energy, and the radius of aM1.4. Our results show that whereas the considered EoS are compatible with the largest masses observed up to now, only five microscopic models and four Skyrme forces are simultaneously compatible with the present constraints on L and the PREX experimental data on the208Pb neutron-skin thickness. We find that all the NLWM and DDM models and the majority of the Skyrme forces are excluded by these two experimental constraints, and that the analysis of the data collected by the NICER mission excludes most of the NLWM considered.Conclusion.The tidal deformability of aM1.4and the neutron-skin thickness of atomic nuclei show some degree of correlation with nuclear and astrophysical observables, which however depends on the ensemble of adopted EoS.