[Prex] Decoding the Density Dependence of the Nuclear Symmetry Energy

[Jay Benesch]

https://arxiv.org/abs/2106.10119

Decoding the Density Dependence of the Nuclear Symmetry Energy
W. G. Lynch, M. B. Tsang

    The large imbalance in the neutron and proton densities in very neutron rich systems increases the nuclear symmetry energy so that it governs many aspects of neutron stars and their mergers. Extracting the density dependence of the symmetry energy therefore constitutes an important scientific objective. Many analyses have been limited to extracting values for the symmetry energy, S0, and its ``derivative'', L, at saturation density ρ0≈2.6×1014 g/cm3 ≈0.16 nucleons/fm3, resulting in constraints that appear contradictory. We show that most experimental observables actually probe the symmetry energy at densities far from ρ0, making the extracted values of S0 or L imprecise. By focusing on the densities these observables actually probe, we obtain a detailed picture of the density dependence of the symmetry energy from 0.25ρ0 to 1.5ρ0. From this experimentally derived density functional, we extract L01=53.1±6.1MeV at ρ≈0.10 fm−3, a neutron skin thickness for 208Pb of Rnp= 0.23±0.04 fm, a symmetry pressure at saturation density of P0=3.2±1.2MeV/fm3 and suggests a radius for a 1.4 solar mass neutron star of 13.1±0.6 km. 

Comments: 	6 pages, 4 figures
Subjects: 	Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR); Nuclear Experiment (nucl-ex)
Cite as: 	arXiv:2106.10119 [nucl-th]