Density slope of the nuclear symmetry energy from the neutron skin thickness of heavy nuclei

TL;DR

This paper investigates how measurements of neutron skin thickness in heavy nuclei can constrain the density dependence of the nuclear symmetry energy, with implications for neutron star properties.

Contribution

It establishes correlations between neutron skin thickness and symmetry energy parameters using Skyrme-Hartree-Fock, providing new constraints on the slope of the symmetry energy.

Findings

Neutron skin data constrains symmetry energy slope L.

Combined data tightens limits on L independently of E_{sym}( ho_0).

Implications for neutron star crust properties and core-crust transition density.

Abstract

Expressing explicitly the parameters of the standard Skyrme interaction in terms of the macroscopic properties of asymmetric nuclear matter, we show in the Skyrme-Hartree-Fock approach that unambiguous correlations exist between observables of finite nuclei and nuclear matter properties. We find that existing data on neutron skin thickness $\Delta r_{np}$ of Sn isotopes give an important constraint on the symmetry energy $E_{sym}({\rho _{0}})$ and its density slope $L$ at saturation density ${\rho _{0}}$. Combining these constraints with those from recent analyses of isospin diffusion and double neutron/proton ratio in heavy-ion collisions at intermediate energies leads to a more stringent limit on $L$ approximately independent of $E_{sym}({\rho _{0}})$. The implication of these new constraints on the $\Delta r_{np}$ of $^{208}$Pb as well as the core-crust transition density and pressure in neutron stars is discussed.