Prof. David Blaschke (UWr & JINR)

Third family of compact stars with a nonlocal chiral quark model EoS

We show that the quark matter equation of state (EoS) obtained within a color superconducting chiral quark model with nonlocal, covariant interactions does not allow for obtaining a third family of hybrid compact stars unless one invokes a density dependence of the vector meson coupling and a density-dependent bag pressure. These density dependences are of the model parameters are obtained from a matching with the string-flip model EoS [Kaltenborn et al., PRD (2017)] for three cases of the screening parameter alpha = 0.20, 0.24, and 0.30. Modern constraints from compact star phenomenology are discussed for these EoS.