Neutron stars in relativistic mean field theory with isovector scalar meson

摘要

We study the equation of state (EOS) of neutron star matter in a relativistic mean field (RMF) theory with the isovector scalar mean field corresponding to the (delta)-meson (a(sub 0)(980)). A range of values of the (delta)-meson coupling compatible with the Bonn potentials is explored. Parameters of the model in the isovector sector are constrained to fit the nuclear symmetry energy, E(sub s) (approx) 30 MeV. We find that proton fraction of neutron star matter is higher in the presence of the (delta)-field whereas the energy per particle is lower. The EOS becomes slightly stiffer and the maximum mass of the neutron star increased with increasing (delta)meson coupling. The effect is stronger for soft EOS. (author). 7 refs, 6 figs, 1 tab.