Effect of nucleon coupling constants on the mass radius ratio of proto neutron star PSR J0737-3039A
Abstract
The effect of the nucleon coupling constants on the mass radius ratio (further, the surface gravitational redshift) of proto neutron star (PNS) PSR J0737-3039A is examined with relativistic mean field theory in consideration of a baryon octet. Here, five sets of nucleon coupling constants DD-MEI, GL85, GL97, GM1 and NL2 are used. The PNS’s temperature is assumed to be T=20 MeV and the mass the PNS PSR J0737-3039A is chosen as M=1.338M⊙. The radius and the mass radius ratio of the PNS PSR J0737-3039A calculated by the five groups of nucleon coupling constants above are R=15.693–18.846 km and M/R=0.071–0.085M⊙/km, respectively. The surface gravitational redshift z of the PNS PSR J0737-3039A calculated from the above five groups of nucleon coupling constants is z=0.125–0.156.
