scholarly journals Reduction of the Mass of the Proto-Quark Star during Cooling

Particles ◽  
2021 ◽  
Vol 4 (1) ◽  
pp. 37-44
Author(s):  
Gevorg Hajyan
Keyword(s):  
Quark Matter ◽  
Finite Temperature ◽  
Supernova Explosion ◽  
Neutrino Emission ◽  
Quark Star ◽  
Bag Model ◽  
Quark Stars ◽  
Mit Bag Model

The integral parameters (mass, radius) of hot proto-quark stars that are formed in supernova explosion are studied. We use the MIT bag model to determine the pressure of up-down and strage quark matter at finite temperature and in the regime where neutrinos are trapped. It is shown that such stars are heated to temperatures of the order of tens of MeV. The maximum possible values of the central temperatures of these stars are determined. It is shown that the energy of neutrinos that are emitted from proto-quark stars is of the order of 250÷300 MeV. Once formed, the proto-quark stars cool by neutrino emission, which leads to a decrease in the mass of these stars by about 0.16–0.25 M⊙ for stars with the rest masses that are in the range Mb=1.22−1.62M⊙.

scholarly journals QUARK STARS AND QUANTUM-MAGNETICALLY INDUCED COLLAPSE

2005 ◽  
Vol 14 (11) ◽  
pp. 1959-1969 ◽  
Author(s):  
A. PÉREZ MARTÍNEZ ◽  
H. PÉREZ ROJAS ◽  
H. J. MOSQUERA CUESTA ◽  
M. BOLIGAN ◽  
M. G. ORSARIA
Keyword(s):  
Neutron Stars ◽  
Magnetic Moment ◽  
Anomalous Magnetic Moment ◽  
Quark Matter ◽  
Strange Quark ◽  
Vacuum Energy Density ◽  
Bag Model ◽  
X Ray ◽  
Quark Stars ◽  
Mit Bag Model

Quark matter is expected to exist in the interior of compact stellar objects as neutron stars or even the more exotic strange stars, based on the Bodmer–Witten conjecture. Bare strange quark stars and (normal) strange quark-matter stars, those possessing a baryon (electron-supported) crust, are hypothesized as good candidates to explain the properties of a set of peculiar stellar sources such as the enigmatic X-ray source RX J1856.5-3754, some pulsars such as PSR B1828-11 and PSR B1642-03, and the anomalous X-ray pulsars and soft γ-ray repeaters. In the MIT bag model, quarks are treated as a degenerate Fermi gas confined to a region of space having a vacuum energy density B bag (the Bag constant). In this note, we modify the MIT bag model by including the electromagnetic interaction. We also show that this version of the MIT model implies the anisotropy of the bag pressure due to the presence of the magnetic field. The equations of state of the degenerate quarks gases are studied in the presence of ultra strong magnetic fields. The behavior of a system made up of quarks having (or not) anomalous magnetic moment is reviewed. A structural instability is found, which is related to the anisotropic nature of the pressures in this highly magnetized matter. The conditions for the collapse of this system are obtained and compared to a previous model of neutron stars that is built on a neutron gas having anomalous magnetic moment.

scholarly journals QUARK STARS ADMITTING A ONE-PARAMETER GROUP OF CONFORMAL MOTIONS

2004 ◽  
Vol 13 (01) ◽  
pp. 149-156 ◽  
Author(s):  
M. K. MAK ◽  
T. HARKO
Keyword(s):  
Analytical Solution ◽  
Quark Matter ◽  
Spherical Symmetry ◽  
Total Mass ◽  
Strange Quark ◽  
Exact Analytical Solution ◽  
Quark Star ◽  
Parameter Group ◽  
Quark Stars

An exact analytical solution describing the interior of a charged strange quark star is found under the assumption of spherical symmetry and the existence of a one-parameter group of conformal motions. The solution describes a unique static charged configuration of quark matter with radius R=9.46 km and total mass M=2.86M⊙.

scholarly journals Stable Up-Down Quark Matter Nuggets, Quark Star Crusts, and a New Family of White Dwarfs

Galaxies ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 70
Author(s):  
Lang Wang ◽  
Jian Hu ◽  
Cheng-Jun Xia ◽  
Jian-Feng Xu ◽  
Guang-Xiong Peng ◽  
...  
Keyword(s):  
Quark Matter ◽  
White Dwarfs ◽  
Maximum Mass ◽  
Quark Star ◽  
Small Surface ◽  
New Family ◽  
Quark Stars ◽  
Down Quark ◽  
The Stability ◽  
Chandrasekhar Limit

The possible existence of stable up-down quark matter (udQM) was recently proposed, and it was shown that the properties of udQM stars are consistent with various pulsar observations. In this work we investigate the stability of udQM nuggets and found at certain size those objects are more stable than others if a large symmetry energy and a small surface tension were adopted. In such cases, a crust made of udQM nuggets exists in quark stars. A new family of white dwarfs comprised entirely of udQM nuggets and electrons were also obtained, where the maximum mass approaches to the Chandrasekhar limit.

scholarly journals Identifying QCD Phase Transitions via the Gravitational Wave Frequency from a Supernova Explosion

2021 ◽  
Vol 922 (2) ◽  
pp. 266
Author(s):  
Zhan Bai ◽  
Wei-jie Fu ◽  
Yu-xin Liu
Keyword(s):  
Strange Quark ◽  
Degrees Of Freedom ◽  
Supernova Explosion ◽  
Strange Quark Matter ◽  
The Other ◽  
Qcd Phase Transition ◽  
Quark Stars ◽  
Mit Bag Model ◽  
Strong Interaction Matter ◽  
Nonradial Oscillations

Abstract We investigate the nonradial oscillations of newly born neutron stars (NSs) and strange quark stars (SQSs). This is done with the relativistic nuclear field theory with hyperon degrees of freedom employed to describe the equation of state (EoS) for the stellar matter in NSs, and with both the MIT bag model and the Nambu–Jona-Lasinio model adopted to construct the configurations of the SQSs. We find that the gravitational-mode (g-mode) eigenfrequencies of newly born SQSs are significantly lower than those of NSs, which is independent of models implemented to describe the EoS for the strange quark matter. Meanwhile, the eigenfrequencies of the other modes of nonradial oscillations, e.g., fundamental (f)- and pressure (p)-modes, are much larger than those of the g-mode, and are related to the stiffness of the EoSs. In light of the first direct observation of gravitational waves (GWs), it is promising to employ GWs to identify the QCD phase transition in high-density strong-interaction matter.

scholarly journals MASS–RADIUS RELATION FOR MAGNETIZED STRANGE QUARKS STARS

2010 ◽  
Vol 19 (08n10) ◽  
pp. 1511-1519 ◽  
Author(s):  
A. P. MARTÍNEZ ◽  
R. G. FELIPE ◽  
D. M. PARET
Keyword(s):  
Magnetic Field ◽  
Quark Matter ◽  
Strange Quark ◽  
Baryon Density ◽  
Strange Quark Matter ◽  
Strange Quarks ◽  
Quark Stars ◽  
Mit Bag Model ◽  
The Stability ◽  
The Magnetic Field

We review the stability of magnetized strange quark matter (MSQM) within the phenomenological MIT bag model, taking into account the variation of the relevant input parameters, namely, the strange quark mass, baryon density, magnetic field and bag parameter. A comparison with magnetized asymmetric quark matter in β-equilibrium as well as with strange quark matter (SQM) is presented. We obtain that the energy per baryon for MSQM decreases as the magnetic field increases, and its minimum value at vanishing pressure is lower than the value found for SQM, which implies that MSQM is more stable than non-magnetized SQM. The mass–radius relation for magnetized strange quark stars is also obtained in this framework.

scholarly journals ROTATING QUARK STAR IN CHIRAL COLOUR DIELECTRIC MODEL

2007 ◽  
Vol 22 (14) ◽  
pp. 1019-1029 ◽  
Author(s):  
ABHIJIT BHATTACHARYYA ◽  
SANJAY K. GHOSH
Keyword(s):  
Equation Of State ◽  
Model Equation ◽  
Quark Star ◽  
Circular Orbits ◽  
Bag Model ◽  
Mit Bag Model ◽  
Dielectric Model

The properties of rotating quark star are studied using the equation of state obtained from chiral colour dielectric model. The results are compared with those obtained from MIT bag model equation of state. The frequencies in the corotating innermost circular orbits for different central densities are evaluated and compared with the observed data.

scholarly journals Quark matter and quark stars at finite temperature in Nambu–Jona-Lasinio model

2017 ◽  
Vol 77 (8) ◽  
Author(s):  
Peng-Cheng Chu ◽  
Xiao-Hua Li ◽  
Bin Wang ◽  
Yu-Min Dong ◽  
Yu-Yue Jia ◽  
...  
Keyword(s):  
Quark Matter ◽  
Finite Temperature ◽  
Quark Stars

scholarly journals Quark matter revisited with non-extensive MIT bag model

2017 ◽  
Vol 53 (10) ◽  
Author(s):  
Pedro H. G. Cardoso ◽  
Tiago Nunes da Silva ◽  
Airton Deppman ◽  
Débora P. Menezes
Keyword(s):  
Quark Matter ◽  
Bag Model ◽  
Mit Bag Model
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