Hybrid Stars in an SU(3) Parity Doublet Model
  We apply an extended version of the SU(3) parity model, containing quark degrees of freedom, to study neutron stars. The model successfully reproduces the main thermodynamic features of QCD which allows us to describe the composition of dense matter. Chiral symmetry restoration is realized inside the star and the chiral partners of the baryons appear, their masses becoming degenerate. Furthermore, quark degrees of freedom appear in a transition to a deconfined state. Performing an investigation of the macroscopic properties of neutron stars, we show that observational constraints, like mass and thermal evolution, are satisfied and new predictions can be made. 
V. Dexheimer, J. Steinheimer, R. Negreiros and S. Schramm
astro-ph.HE astro-ph.SR nucl-th