H. Grigorian

Constraints on the high-density nuclear equation of state from the phenomenology of compact stars and heavy-ion collisions

A new scheme for testing nuclear matter equations of state (EoSs) at high densities using constraints from neutron star (NS) phenomenology and a flow data analysis of heavy-ion collisions is suggested. An acceptable EoS shall not allow the direct Urca process to occur in NSs with masses below 1.5M� , and also shall not contradict flow and kaon production data of heavy-ion collisions. Compact star constraints include the mass

Modern compact star observations and the quark matter equation of state

Abstract We present a hybrid equation of state (EoS) for dense matter that satisfies phenomenological constraints from modern compact star (CS) observations which indicate high maximum masses ( M ∼ 2 M ⊙ ) and large radii ( R > 12 km ). The corresponding isospin symmetric EoS is consistent with flow data analyses of heavy-ion collisions and a deconfinement transition at ∼ 0.55 fm −3 . The quark matter phase is described by a 3-flavor Nambu–Jona-Lasinio model that accounts for scalar diquark condensation and vector meson interactions while the nuclear matter phase is obtained within the Dirac–Brueckner–Hartree–Fock (DBHF) approach using the Bonn-A potential. We demonstrate that both pure neutron stars and neutron stars with quark matter cores are consistent with modern CS observations. Hybrid star configurations with a CFL quark core are unstable within the present model.

Phase diagram of three-flavor quark matter under compact star constraints

The phase diagram of three-flavor quark matter under compact star constraints is investigated within a Nambu--Jona-Lasinio model. Global color and electric charge neutrality is imposed for

Cooling of neutron stars. Hadronic model

\ensuremath{\beta}

Cooling of hybrid neutron stars and hypothetical self-bound objects with superconducting quark cores

-equilibrated superconducting quark matter. The constituent quark masses and the diquark condensates are determined self-consistently in the plane of temperature and quark chemical potential. Both strong and intermediate diquark coupling strengths are considered. We show that in both cases, gapless superconducting phases do not occur at temperatures relevant for compact star evolution, i.e., below

A DYNAMICAL, CONFINING MODEL AND HOT QUARK STARS

T\ensuremath{\sim}50\text{ }\text{ }\mathrm{MeV}

Strangeness in the cores of neutron stars

. The stability and structure of isothermal quark star configurations are evaluated. For intermediate coupling, quark stars are composed of a mixed phase of normal (NQ) and two-flavor superconducting (2SC) quark matter up to a maximum mass of

Neutron star cooling constraints for color superconductivity in hybrid stars

1.21\text{ }\text{ }{M}_{\ensuremath{\bigodot}}

Medium effects in cooling of neutron stars and the 3P2 neutron gap

. At higher central densities, a phase transition to the three-flavor color flavor locked (CFL) phase occurs and the configurations become unstable. For the strong diquark coupling we find stable stars in the 2SC phase, with masses up to

New class of hybrid EoS and Bayesian M - R data analysis

1.33\text{ }\text{ }{M}_{\ensuremath{\bigodot}}