Baryons’ coupling constants in the Sigma–Omega–Rho model and the mass–radius relation of neutron stars in the presence of hyperons

Abstract

It is expected that the density at the center of neutron stars will be high enough that hyperons or quark matter may be present. In this paper, we investigate the presence of hyperons (Λ, Σ−) along with Leptons (Muons, Electrons) and nucleons in the neutron star. For this purpose, we used a relativistic model called the Sigma–omega–rho model. In this method, the coupling constants of the mesons’ interaction with the nucleons were proposed as a function of the mass of the nucleons and baryons. Using this proposed model for the coupling constants, the particles fraction in beta equilibrium is investigated and the neutron star mass–radius profile is obtained in the presence of hyperons. The phenomenon of Hyperon puzzle is also briefly studied.