Neutron Star Properties in a Chiral SU(3) Model

We investigate various properties of neutron star matter within an effective chiral SU(3)_L×SU(3)_R model. The predictions of this model are compared with a Walecka-type model. It is demonstrated that the importance of hyperon degrees depends strongly on the interaction used, even if the equation of state near saturation density is nearly the same in both models. While the Walecka-type model predicts a neutron star core with strangeness fraction f_S~3/4, the chiral model allows only for f_S~1/3 and predicts that Σ⁰, Σ⁺, and Ξ⁰ will not exist in stars, in contrast to the Walecka-type model.