Constraints on the quark matter equation of state from astrophysical observations

TL;DR

This paper investigates the internal structure of neutron stars with both hadronic and quark matter phases, using various models to constrain the quark matter equation of state based on astrophysical observations.

Contribution

It combines multiple quark matter models with a microscopic hadronic EOS to analyze neutron star properties and establish constraints from astrophysical data.

Findings

Two solar mass hybrid stars require a sufficiently stiff nucleonic EOS.

Different quark matter models influence the maximum mass of neutron stars.

Astrophysical observations can constrain the quark matter equation of state.

Abstract

We calculate the structure of neutron star interiors comprising both the hadronic and the quark phases. For the hadronic sector we employ a microscopic equation of state involving nucleons and hyperons derived within the Brueckner-Hartree-Fock many-body theory with realistic two-body and three-body forces. For the description of quark matter, we use several different models, e.g. the MIT bag, the Nambu--Jona-Lasinio (NJL), the Color Dielectric (CDM), the Field Correlator method (FCM), and one based on the Dyson-Schwinger model (DSM). We find that a two solar mass hybrid star is possible only if the nucleonic EOS is stiff enough.