Nuclear matter and neutron star properties with the extended Nambu-Jona-Lasinio model * * Supported by Hunan Provincial Natural Science Foundation of China (2015JJ2005), the Science Research Foundation of Education Department of Hunan Province (15C0029), the National Natural Science Foundation of China (11103001), and the construct program of the key discipline in Hunan province

Abstract

An extended Nambu-Jona-Lasinio (eNJL) model with nucleons as the degrees of freedom is used to investigate properties of nuclear matter and neutron stars (NSs), including the binding energy and symmetry energy of the nuclear matter, the core-crust transition density, and mass-radius relation of NSs. The fourth-order symmetry energy at saturation density is also investigated. When the bulk properties of nuclear matter at saturation density are used to determine the model parameters, the double solutions of parameters are obtained for a given nuclear incompressibility. It is shown that the isovector-vector interaction has a significant influence on the nuclear matter and NS properties, and the sign of isovector-vector coupling constant is critical in the determination of the trend of the symmetry energy and equation of state. The effects of the other model parameters and symmetry energy slope at saturation density are discussed.