Δ excitation and its influences on neutron stars in relativistic mean field theory

Abstract

The relativistic mean field models with the different parameter sets are extended to investigate the properties of $\ensuremath{\Delta}$-excited nuclear matter. The calculated results show that the critical densities for the $\ensuremath{\Delta}$-excited nuclear matter predicted in a chiral hadronic model are larger than those obtained in the nonlinear Walecka model with the parameter sets Tm1 and NL1. The inclusion of the $\ensuremath{\Delta}$ leads to the decrease in the maximum mass of neutron stars in a chiral hadronic model, while the opposite behavior is shown in the nonlinear Walecka model.