A set of hadronic equations of state (EoSs) derived from relativistic density-functional theory and constrained by terrestrial experiments, astrophysical observations, in particular by the GW170817 event, and chiral effective field theory $\left(\chi \mathrm{EFT}\right)$ of neutron matter is used to explore the sensitivity of the EoS parameterization on the few nuclear-matter characteristics defined at the saturation density. We find that the gross properties of compact stars are most sensitive to the isoscalar skewness coefficient $Q_{\text{sat}}$ and the isovector slope coefficient $L_{\text{sym}}$ around saturation density, since the higher-order coefficients, such as $K_{\text{sym}}$, are fixed by our model. More specifically, (i) among these $Q_{\text{sat}}$ is the dominant parameter controlling both the maximum mass and the radii of compact stars while $L_{\mathrm{sym}}$ is constrained somewhat by $\chi \mathrm{EFT}$ of neutron matter, (ii) massive-enough $(M\sim 2.0M_{\odot })$ compact stars featuring both hyperons and $\mathrm{\Delta }$ resonances can be obtained if the value of $Q_{\text{sat}}$ is large enough, and (iii) the emergence of $\mathrm{\Delta }$'s reduces the radius of a canonical mass $(M\sim 1.4M_{\odot })$ compact star thus easing the tension between the predictions of the relativistic density functionals and the inferences from the x-ray observation of nearby isolated neutron stars.

• Received 10 January 2019

DOI:https://doi.org/10.1103/PhysRevC.100.015809