SU(2) Chiral Sigma Model and Properties of Neutron Stars

We discuss the {\it SU}(2) chiral sigma model in the context of nuclearmatter using a mean field approach at high density. In this model we include adynamically generated isoscalar vector field and higher-order terms in thescalar field. With the inclusion of these, we reproduce the empirical values ofthe nuclear matter saturation density, binding energy, and nuclearincompressibility. The value of the incompressibility is chosen according torecently obtained heavy-ion collision data. We then apply the same dynamicalmodel to neutron-rich matter in beta equilibrium, related to neutron starstructure. The maximum mass and corresponding radius of stable non-rotatingneutron stars are found to be in the observational limit.Comment: 9 pages, 3 figures, corrected some paragraphs and typos, published in Prog. Theor. Phys. V.104, pp. 1163-1171 (2000