Equation of state of a quasiparticle model at finite chemical potential and quark star

We discuss the statistical mechanics and thermodynamics of quark matter at zero temperature and finite chemical potential using a thermodynamically consistent framework of quasiparticle model for QGP without the need of any reformulation of statistical mechanics or thermodynamical consistency relation. Using that equation of state, we solve the Tolman–Oppenheimer–Volkoff equation to obtain the mass-radius relation of dense quark star.

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Equation of state for holographic nuclear matter as instanton gas

EPJ Web of Conferences ◽

10.1051/epjconf/202225807005 ◽

2022 ◽

Vol 258 ◽

pp. 07005

Author(s):

Kazuo Ghoroku ◽

Kouji Kashiwa ◽

Yoshimasa Nakano ◽

Motoi Tachibana ◽

Fumihiko Toyoda

Keyword(s):

Equation Of State ◽

Nuclear Matter ◽

Chemical Potential ◽

Compact Star ◽

Superconducting Phase ◽

Holographic Model ◽

Quark Star ◽

Baryon Chemical Potential ◽

Dilute Gas ◽

The One

In a holographic model, which was used to investigate the color superconducting phase of QCD, a dilute gas of instantons is introduced to study the nuclear matter. The free energy of the nuclear matter is computed as a function of the baryon chemical potential in the probe approximation. Then the equation of state is obtained at low temperature. Using the equation of state for the nuclear matter, the Tolman-Oppenheimer-Volkov equations for a cold compact star are solved. We find the mass-radius relation of the star, which is similar to the one for quark star. This similarity implies that the instanton gas given here is a kind of self-bound matter.

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EQUATION OF STATE OF ASYMMETRIC NUCLEAR MATTER WITH GOGNY AND COULOMB INTERACTIONS

Modern Physics Letters A ◽

10.1142/s0217732390001190 ◽

1990 ◽

Vol 05 (14) ◽

pp. 1071-1080 ◽

Cited By ~ 7

Author(s):

S. W. HUANG ◽

M. Z. FU ◽

S. S. WU ◽

S. D. YANG

Keyword(s):

Equation Of State ◽

Nuclear Matter ◽

Coulomb Interaction ◽

Chemical Potential ◽

Compression Modulus ◽

Nucleon Nucleon ◽

Effective Density ◽

Coulomb Interactions ◽

Asymmetric Nuclear Matter ◽

Nucleon Nucleon Interaction

The equation of state of the asymmetric nuclear matter is calculated with the Gogny D1 effective density-dependent nucleon-nucleon interaction and the Coulomb interaction in the framework of the finite-temperature HF method with the rearrangement term. The dependence of the thermodynamical properties such as the critical temperature of the liquid-gas phase transition, the chemical potential, the compression modulus and the entropy on the Coulomb interaction in nuclear matter is treated by using a shielded two-body Coulomb potential and this method has been found to be a reasonable and effective approach.

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Exploring the Partonic Phase at Finite Chemical Potential in and out-of Equilibrium

Particles ◽

10.3390/particles3010015 ◽

2020 ◽

Vol 3 (1) ◽

pp. 178-192 ◽

Cited By ~ 1

Author(s):

O. Soloveva ◽

P. Moreau ◽

L. Oliva ◽

V. Voronyuk ◽

V. Kireyeu ◽

...

Keyword(s):

Cross Sections ◽

Chemical Potential ◽

Transport Coefficients ◽

Gluon Plasma ◽

Entropy Density ◽

Baryon Chemical Potential ◽

Equilibrium Study ◽

200 Gev ◽

Quasiparticle Model ◽

Scattering Cross Sections

We study the influence of the baryon chemical potential μ B on the properties of the Quark–Gluon–Plasma (QGP) in and out-of equilibrium. The description of the QGP in equilibrium is based on the effective propagators and couplings from the Dynamical QuasiParticle Model (DQPM) that is matched to reproduce the equation-of-state of the partonic system above the deconfinement temperature T c from lattice Quantum Chromodynamics (QCD). We study the transport coefficients such as the ratio of shear viscosity η and bulk viscosity ζ over entropy density s, i.e., η / s and ζ / s in the ( T , μ ) plane and compare to other model results available at μ B = 0 . The out-of equilibrium study of the QGP is performed within the Parton–Hadron–String Dynamics (PHSD) transport approach extended in the partonic sector by explicitly calculating the total and differential partonic scattering cross sections based on the DQPM and the evaluated at actual temperature T and baryon chemical potential μ B in each individual space-time cell where partonic scattering takes place. The traces of their μ B dependences are investigated in different observables for symmetric Au + Au and asymmetric Cu + Au collisions such as rapidity and m T -distributions and directed and elliptic flow coefficients v 1 , v 2 in the energy range 7.7 GeV ≤ s N N ≤ 200 GeV.

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Quark Number Susceptibilities and Equation of State in QCD at Finite μB

Proceedings ◽

10.3390/proceedings2019013005 ◽

2019 ◽

Vol 13 (1) ◽

pp. 5

Author(s):

Saumen Datta ◽

Rajiv Gavai ◽

Sourendu Gupta

Keyword(s):

Equation Of State ◽

Taylor Series ◽

Chemical Potential ◽

Baryon Number ◽

Heavy Ion ◽

Relativistic Heavy Ion Collider ◽

Quark Number ◽

Monte Carlo Studies ◽

Essential Input ◽

Beam Energy Scan

One of the main goals of the cold baryonic matter (CBM) experiment at FAIR is to explore the phases of strongly interacting matter at finite temperature and baryon chemical potential μ B . The equation of state of quantum chromodynamics (QCD) at μ B > 0 is an essential input for the CBM experiment, as well as for the beam energy scan in the Relativistic Heavy Ion Collider(RHIC) experiment. Unfortunately, it is highly nontrivial to calculate the equation of state directly from QCD: numerical Monte Carlo studies on lattice are not useful at finite μ B . Using the method of Taylor expansion in chemical potential, we estimate the equation of state, namely the baryon number density and its contribution to the pressure, for two-flavor QCD at moderate μ B . We also study the quark number susceptibilities. We examine the technicalities associated with summing the Taylor series, and explore a Pade resummation. An examination of the Taylor series can be used to get an estimate of the location of the critical point in μ B , T plane.

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Equation of state of sticky-hard-sphere fluids in the chemical-potential route

Physical Review E ◽

10.1103/physreve.89.042121 ◽

2014 ◽

Vol 89 (4) ◽

Cited By ~ 6

Author(s):

René D. Rohrmann ◽

Andrés Santos

Keyword(s):

Equation Of State ◽

Hard Sphere ◽

Chemical Potential

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Equation of State of a Magnetized Dense Neutron System

Universe ◽

10.3390/universe5050104 ◽

2019 ◽

Vol 5 (5) ◽

pp. 104 ◽

Cited By ~ 2

Author(s):

Efrain J. Ferrer ◽

Aric Hackebill

Keyword(s):

Magnetic Field ◽

Equation Of State ◽

Chemical Potential ◽

Compact Objects ◽

Field Direction ◽

Neutron Density ◽

Magnetic Field Direction ◽

System Equation ◽

The One ◽

The Magnetic Field

We discuss how a magnetic field can affect the equation of state of a many-particle neutron system. We show that, due to the anisotropy in the pressures, the pressure transverse to the magnetic field direction increases with the magnetic field, while the one along the field direction decreases. We also show that in this medium there exists a significant negative field-dependent contribution associated with the vacuum pressure. This negative pressure demands a neutron density sufficiently high (corresponding to a baryonic chemical potential of μ = 2.25 GeV) to produce the necessary positive matter pressure that can compensate for the gravitational pull. The decrease of the parallel pressure with the field limits the maximum magnetic field to a value of the order of 10 18 G, where the pressure decays to zero. We show that the combination of all these effects produces an insignificant variation of the system equation of state. We also found that this neutron system exhibits paramagnetic behavior expressed by the Curie’s law in the high-temperature regime. The reported results may be of interest for the astrophysics of compact objects such as magnetars, which are endowed with substantial magnetic fields.

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