Hybrid Stars in the Framework of NJL Models

GUSTAVO A. CONTRERA; MILVA G. ORSARIA; IGNACIO FRANCISCO RANEA SANDOVAL; FRIDOLIN WEBER

Workshop; 7th International Workshop on Astronomy and Relativistic Astrophysics (IWARA 2016); 2016

We compute models for the equation of state (EoS) of the matter in the cores of hybridstars. Hadronic matter is treated in the non-linear relativistic mean-field approximation,and quark matter is modeled by three-flavor local and non-local Nambu−Jona-Lasinio(NJL) models with repulsive vector interactions. The transition from hadronic to quarkmatter is constructed by considering either a soft phase transition (Gibbs construction)or a sharp phase transition (Maxwell construction). We find that high-mass neutron starswith masses up to 2.1 − 2.4M may contain a mixed phase with hadrons and quarks intheir cores, if global charge conservation is imposed via the Gibbs conditions. However,if the Maxwell conditions is considered, the appearance of a pure quark matter coreeither destabilizes the star immediately (commonly for non-local NJL models) or leadsto a very short hybrid star branch in the mass-radius relation (generally for local NJLmodels).