Constraints on the isovector properties of finite nuclei from neutron stars observations

Abstract

The nuclear symmetry energy plays important role on the structure of finite nuclei as well as on the bulk properties of neutron stars. However, its values at high densities are completely uncertain and the corresponding experimental data have a large error. One possibility to determine or at least estimate the values at high densities is with the help of neutron star observations. Recently, observations of gravitational waves from merging processes of binary neutron star systems provide useful information on both their radius and tidal deformability, quantities directly related to the symmetry energy. In this work, an attempt is made in this direction, namely to see how recent observations can help to constrain the structure of finite nuclei. In particular, in the present study we parameterize the equation of state which describes the asymmetric and symmetric nuclear mater with the help of the parameter $\eta =(K_0{L}^2{)}^{1/3}$, where $K_0$ is the incompressibility and $L$ the slope parameter. The parameter $\eta$ is a regulator of the stiffness of the equation of state. We expect that the values of $\eta$ affect both the properties of finite nuclei as well as of the neutron star properties (where the role of the isovector interaction plays important role). It is natural to expect that constraints, via the parameter $\eta$ on finite nuclei will imply constraints on the neutron star properties and vice versa. In view of the above statements we propose a simple but self-consistent method to examine simultaneously the effects of the parameter $\eta$ on the properties of finite nuclei and neutron stars. We found constraints on the latter systems via combination by the recent experiments (PREX-2) and observational data found by the detectors Ligo and Virgo.

Comments: 11 pages, 6 figures. Any comments are welcome