Sigma model calculations of neutron-rich nuclear matter

Abstract
We examine the role of many-body effects provided by the chiral sigma model in the equation of state of symmetric nuclear matter and neutron-rich matter. Using the parameters determined by fitting the known equilibrium properties of symmetric and slightly neutron-rich matter, the equation of state with arbitrary neutron excess is calculated. The role of the nuclear symmetry energy on the structure of beta stable neutron stars is discussed.