Constraining Hadronquark Phase Transition Parameters within the Quarkmeanfield Model Using Multimessenger Observations of Neutron Stars
Abstract
We extend the quark meanfield (QMF) model for nuclear matter and study the possible presence of quark matter inside the cores of neutron stars. A sharp firstorder hadronquark phase transition is implemented combining the QMF for the hadronic phase with "constantspeedofsound" parameterization for the highdensity quark phase. The interplay of the nuclear symmetry energy slope parameter, L, and the dimensionless phase transition parameters (the transition density n_{trans}/n_{0}, the transition strength Δɛ/ɛ_{trans}, and the sound speed squared in quark matter ${c}_{\mathrm{QM}}^{2}$ ) are then systematically explored for the hybrid star properties, especially the maximum mass M_{max} and the radius and the tidal deformability of a typical 1.4 M_{⊙} star. We show the strong correlation between the symmetry energy slope L and the typical stellar radius R_{1.4}, similar to that previously found for neutron stars without a phase transition. With the inclusion of phase transition, we obtain robust limits on the maximum mass (M_{max} < 3.6 M_{⊙}) and the radius of 1.4 M_{⊙} stars (R_{1.4} ≳ 9.6 km), and we find that a phase transition that is too weak (Δɛ/ɛ_{trans} ≲ 0.2) taking place at low densities ≲1.31.5 n_{0} is strongly disfavored. We also demonstrate that future measurements of the radius and tidal deformability of ∼1.4 M_{⊙} stars, as well as the mass measurement of very massive pulsars, can help reveal the presence and amount of quark matter in compact objects.
 Publication:

The Astrophysical Journal
 Pub Date:
 December 2020
 DOI:
 10.3847/15384357/abbd41
 arXiv:
 arXiv:2006.00839
 Bibcode:
 2020ApJ...904..103M
 Keywords:

 Neutron star cores;
 Neutron stars;
 1107;
 1108;
 Nuclear Theory;
 Astrophysics  High Energy Astrophysical Phenomena;
 Astrophysics  Solar and Stellar Astrophysics
 EPrint:
 15 pages, 12 figures, 1 table, version accepted for publication in ApJ