Related papers: State of matter for quark stars
Quark clustering could occur in cold quark matter because of the strong coupling between quarks at realistic baryon densities of compact stars. Although one may still not be able to calculate this conjectured matter from first principles,…
Two kinds of difficulties have challenged the physics community for many years: (1) knowing nature's building blocks (particle physics) and (2) understanding interacting many-body systems (many-body physics). Both of them exist in the…
It is still a matter of debate to understand the equation of state of cold supra-nuclear matter in compact stars because of unknown on-perturbative strong interaction between quarks. Nevertheless, it is speculated from an astrophysical view…
From a model-independent point of view, we address the possibility that quark clustering could occur in cold quark matter at realistic baryon densities because of the likely strong coupling between quarks in compact stars.
The study of dense matter at ultra-high density has a very long history, which is meaningful for us to understand not only cosmic events in extreme circumstances but also fundamental laws of physics. It is well known that the state of cold…
The state of super-dense matter is essential for us to understand the nature of pulsars, but the non- perturbative quantum chromodynamics (QCD) makes it very difficult for direct calculations of the state of cold matter at realistic baryon…
A quark-cluster state, rather than the color-super-conductivity state, may appear in matter with low-temperature but high density, since the phase transition of chiral symmetry broken and that of color-confinement could not occur…
As a model for nonideal behavior in the equation of state of QCD at high density, we consider cold quark matter in perturbation theory. To second order in the strong coupling constant, $\alpha_s$, the results depend sensitively on the…
The matter inside pulsar-like compact stars could be in a quark-cluster phase since in cold dense matter at a few nuclear densities (2 to 10 times), quarks could be coupled still very strongly and condensate in position space to form quark…
A polytropic quark star model is suggested in order to establish a general framework in which theoretical quark star models could be tested by observations. The key difference between polytropic quark stars and the polytropic model studied…
It is conventionally thought that the state equation of dense matter softens and thus cannot result in high maximum mass if pulsars are quark stars, and that a recently discovered $2M_\odot$ pulsar (PSR J1614-2230) may make quark stars to…
The question of whether quark matter exists in neutron stars is a long standing one. Generally one finds that a first order phase transition from baryons to quarks softens the equation of state so much that the star would collapse into a…
Compact stars with significant high densities in their interiors can give rise to quark deconfined phases that can open a window for the study of strongly interacting dense nuclear matter. Recent observations on the mass of two pulsars, PSR…
The recent measurement of a $1.97\pm 0.04$ solar-mass pulsar places a stringent lower bound on the maximum mass of compact stars and therefore challenges the existence of any agents that soften the equation of state of ultra-dense matter.…
Strange quark matter in beta equilibrium at high densities is studied in a quark confinement model. Two equations of state are dynamically generated for the {\it same} set of model parameters used to describe the nucleon: one corresponds to…
Under extreme conditions of temperature and/or density, quarks and gluons are expected to undergo a deconfinement phase transition. While this is an ephemeral phenomenon at the ultra-relativistic heavy-ion collider (BNL-RHIC), quark matter…
The nature of pulsar-like compact stars is still in controversy although the first pulsar was found more than 40 years ago. Generally speaking, conventional neutron stars and non-mainstream quark stars are two types of models to describe…
High massive compact stars have been reported recently in the literature, providing strong constraints on the properties of the ultradense matter beyond the saturation nuclear density. In view of these results, the calculations of quark…
The density in the core of neutron stars can reach values of about 5 to 10 times nuclear matter saturation density. It is, therefore, a natural assumption that hadrons may have dissolved into quarks under such conditions, forming a hybrid…
It is a pity that the real state of matter in pulsar-like stars is still not determined confidently because of the uncertainty about cold matter at supranuclear density, even 40 years after the discovery of pulsar. Nuclear matter (related…