Abstract
In this paper, we use a three flavor non-local Nambu–Jona-Lasinio (NJL) model, an improved effective model of Quantum Chromodynamics (QCD) at low energies, to investigate the existence of deconfined quarks in the cores of neutron stars. Particular emphasis is put on the possible existence of quark matter in the cores of rotating neutron stars (pulsars). In contrast to non-rotating neutron stars, whose particle compositions do not change with time (are frozen in), the type and structure of the matter in the cores of rotating neutron stars depends on the spin frequencies of these stars, which opens up a possible new window on the nature of matter deep in the cores of neutron stars. Our study shows that, depending on mass and rotational frequency, up to around 8% of the mass of a massive neutron star may be in the mixed quark-hadron phase, if the phase transition is treated as a Gibbs transition. We also find that the gravitational mass at which quark deconfinement occurs in rotating neutron stars varies quadratically with spin frequency, which can be fitted by a simple formula.
Highlights
Exploring the properties of compressed baryonic matter, or, more generally, strongly interacting matter at high densities and/or temperatures has become a forefront area of modern physics [1,2,3].Experimentally, the properties of such matter are being probed with the Relativistic Heavy IonCollider RHIC at Brookhaven and the Large Hadron Collider (LHC) at Cern
The quark-hadron mixed phase as well as several different hyperon species are successively spun out of the neutron star if the rotation rate increases toward the Kepler frequency
As can be seen in this figure, up to 8% of the total gravitational mass of these neutron stars exists in the form a mixed quark-hadron phase
Summary
Exploring the properties of compressed baryonic matter, or, more generally, strongly interacting matter at high densities and/or temperatures has become a forefront area of modern physics [1,2,3]. The universe was filled with hot and dense baryonic matter shortly after the Big Bang Today, such matter is being created in the universe in the final stages of catastrophic stellar events (e.g., core-collapse supernovae, gamma-ray bursts) and exists permanently inside of neutron stars. Number of pulsars that new particle states may appear and novel states of matter, foremost quark matter, may be created This feature makes neutron stars superb astrophysical laboratories for a wide range of physical studies [4,5,6,7,9,11,13,14]. We use a non-local extension of the SU(3) Nambu–Jona-Lasinio (NJL) model to investigate the possible existence of deconfined quarks in the cores of neutron stars. In Refs. [15,16]
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call