科研之友
微信
新浪微博
Facebook
分享链接
摘要
The density-dependent relativistic Hartree-Fock (DDRHF) theory is extended to include Delta isobars for the study of dense nuclear matter and neutron stars. To this end, we solve the Rarita-Schwinger equation for spin-3/2 particle. Both the direct and exchange terms of the Delta isobars' self-energies are evaluated in detail. In comparison with the relativistic mean field theory (Hartree approximation), a weaker parameter dependence is found for DDRHF. An early appearance of Delta isobars is recognized rho(B) similar to 0.28 fm(-3), comparable with that of hyperons. Also, we find that the Delta isobars' softening of the equation of state is mainly due to the reduced Fock contributions from the coupling of the isoscalar mesons, while the pion contributions are negligibly small. We finally conclude that with typical parameter sets, neutron stars with Delta isobars in their interiors could be as heavy as the two massive pulsars whose masses are precisely measured, with slightly smaller radii than normal neutron stars.
