The binary neutron-star merger event, GW170817, has cast a new light on nuclear physics research. Using a neutron-star model that includes a crust equation of state (EoS), we calculate the properties of a 1.4 solar-mass neutron star. The model incorporates more than 200 Skyrme energy density functionals, which describe nuclear matter properties, in the outer liquid core region of the neutron star. We find a power-law relation between the neutron-star tidal deformability, Λ, and the neutron-star radius, R. Without an explicit crust EoS, the model predicts smaller R and the difference becomes significant for stars with large radii. To connect the neutron star properties with nuclear matter properties, we confront the predicted values for Λ, against the Taylor expansion coefficients of the Skyrme interactions. There is no pronounced correlation between Skyrme parameters in symmetric nuclear matter and neutron star properties.However, we find the strongest correlation between Λ and Ksym, the curvature of the density dependence of the symmetry energy at saturation density. At twice the saturation density, our calculations show a strong correlation between Λ and total pressure providing guidance to laboratory nucleus-nucleus collision experiments.

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A B S T R A C TEfficiency corrected single ratios of neutron and proton spectra in central 112 Sn+ 112 Sn and 124 Sn+ 124 Sn collisions at 120 MeV/u are combined with double ratios to provide constraints on the density and momentum dependencies of the isovector mean-field potential. Bayesian analyses of these data reveal that the isoscalar and isovector nucleon effective masses, * − * are strongly correlated. The linear correlation observed in * − * yields a nearly independent constraint on the effective mass splitting Δ * = ( * − * )∕ = −0.05 +0.09 −0.09 . The correlated constraint on the standard symmetry energy, 0 and the slope, at saturation density yields the values of symmetry energy ( ) = 16.8 +1.2 −1.2 MeV at a sensitive density of ∕ 0 = 0.43 +0.05 −0.05 .

The LIGO-Virgo collaboration detection of the binary neutron-star merger event, GW170817, has expanded efforts to understand the Equation of State (EoS) of nuclear matter. These measurements provide new constraints on the overall pressure, but do not elucidate its origins, by not distinguishing the contribution to the pressure from symmetry energy which governs much of the internal structure of a neutron star. By combining the neutron star EoS extracted from the GW170817 event and the EoS of symmetric matter from nucleus-nucleus collision experiments, we extract the symmetry pressure, which is the difference in pressure between neutron and nuclear matter over the density region from 1.20 to 4.50. While the uncertainties in the symmetry pressure are large, they can be reduced with new experimental and astrophysical results.

The structure of the extremely proton-rich nucleus 11 8 O3, the mirror of the two-neutron halo nucleus 11 3 Li8, has been studied experimentally for the first time. Following two-neutron knockout reactions with a 13 O beam, the 11 O decay products were detected after two-proton emission and used to construct an invariant-mass spectrum. A broad peak of width ∼3 MeV was observed. Within the Gamow coupled-channel approach, it was concluded that this peak is a multiplet with contributions from the four-lowest 11 O resonant states: J π =3/2 − 1 , 3/2 − 2 , 5/2 + 1 , and 5/2 + 2. The widths and configurations of these states show strong, non-monotonic dependencies on the depth of the p-9 C potential. This unusual behavior is due to the presence of a broad threshold resonant state in 10 N, which is an analog of the virtual state in 10 Li in the presence of the Coulomb potential. After optimizing the model to the data, only a moderate isospin asymmetry between ground states of 11 O and 11 Li was found.

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