scholarly journals Equation of state for holographic nuclear matter as instanton gas

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.

scholarly journals Holographic colour superconductors at finite coupling with NJL Interactions

2021 ◽  
Vol 81 (12) ◽  
Author(s):  
Kazem Bitaghsir Fadafan ◽  
Jesús Cruz Rojas
Keyword(s):  
Equation Of State ◽  
Cooper Pair ◽  
Chemical Potential ◽  
Coupling Parameter ◽  
Einstein Gravity ◽  
Superconducting Phase ◽  
Holographic Model ◽  
Higher Derivative ◽  
Holographic Qcd ◽  
Holographic Description

AbstractWe study a bottom-up holographic description of the QCD colour superconducting phase in the presence of higher derivative corrections. We expand this holographic model in the context of Gauss–Bonnet (GB) gravity. The Cooper pair condensate has been investigated in the deconfinement phase for different values of the GB coupling parameter $$\lambda _{G B}$$ λ GB , we observe a change in the value of the critical chemical potential $$\mu _c$$ μ c in comparison to Einstein gravity. We find that $$\mu _c$$ μ c grows as $$\lambda _{G B}$$ λ GB increases. We add four fermion interactions and show that in the presence of these corrections the main interesting features of the model are still present and that the intrinsic attractive interaction can not be switched off. This study suggests to find GB corrections to equation of state of holographic QCD matter.

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

1990 ◽  
Vol 05 (14) ◽  
pp. 1071-1080 ◽  
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.

scholarly journals Equation of State of a Magnetized Dense Neutron System

Universe ◽  
2019 ◽  
Vol 5 (5) ◽  
pp. 104 ◽  
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.

PHASE TRANSITION PATTERNS OF NUCLEAR MATTER BASED ON EXTENDED LINEAR SIGMA MODEL

2013 ◽  
Vol 22 (11) ◽  
pp. 1350077 ◽  
Author(s):  
TRAN HUU PHAT ◽  
NGUYEN TUAN ANH ◽  
PHUNG THI THU HA
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Nuclear Matter ◽  
Degrees Of Freedom ◽  
Sigma Model ◽  
Chemical Potential ◽  
Linear Sigma Model ◽  
Baryon Chemical Potential ◽  
Chiral Phase ◽  
The Relationship

We study systematically various types of phase transitions in nuclear matter at finite temperature T and baryon chemical potential μ based on the extended linear sigma model with nucleon degrees of freedom. It is shown that there are three types of phase transitions in nuclear matter: the chiral symmetry nonrestoration (SNR) at high temperature, the well-known liquid–gas (LG) phase transition at sub-saturation density and the Lifshitz phase transition (LPT) from the fully-gapped state to the state with Fermi surface. Their phase diagrams are established in the (T, μ)-plane and their physical properties are investigated in detail. The relationship between the chiral phase transition and the LG phase transition in nuclear matter is discussed.

scholarly journals Holographic cold nuclear matter and neutron star

2014 ◽  
Vol 29 (10) ◽  
pp. 1450060 ◽  
Author(s):  
Kazuo Ghoroku ◽  
Kouki Kubo ◽  
Motoi Tachibana ◽  
Fumihiko Toyoda
Keyword(s):  
Gauge Theory ◽  
Neutron Star ◽  
Equation Of State ◽  
Nuclear Matter ◽  
Fermi Momentum ◽  
The Other ◽  
Holographic Model ◽  
Cold Nuclear Matter ◽  
Theoretical Approaches ◽  
New Phase

We have previously found a new phase of cold nuclear matter based on a holographic gauge theory, where baryons are introduced as instanton gas in the probe [Formula: see text] branes. In our model, we could obtain the equation of state (EOS) of our nuclear matter by introducing Fermi momentum. Then, here we apply this model to the neutron star and study its mass and radius by solving the Tolman–Oppenheimer–Volkoff (TOV) equations in terms of the EOS given here. We give some comments for our holographic model from a viewpoint of the other field theoretical approaches.

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

2012 ◽  
Vol 85 (4) ◽  
Author(s):  
Ya-Lan Tian ◽  
Yan Yan ◽  
Hua Li ◽  
Xin-Lian Luo ◽  
Hong-Shi Zong
Keyword(s):  
Equation Of State ◽  
Chemical Potential ◽  
Quark Star ◽  
Quasiparticle Model

scholarly journals Improving the cold quark-matter pressure via soft interactions at N3LO

2022 ◽  
Vol 258 ◽  
pp. 05004
Author(s):  
Tyler Gorda
Keyword(s):  
Equation Of State ◽  
Quark Matter ◽  
Chemical Potential ◽  
High Momentum ◽  
Leading Order ◽  
Coupling Constant ◽  
Baryon Chemical Potential ◽  
Long Wavelength ◽  
Lengthy Calculation ◽  
Soft Interactions

The propagation of long-wavelength gluons through a dense QCD medium at high baryon chemical potential μB is qualitatively modified by the effects of screening, arising from scatterings off the high-momentum quarks in the medium. This same screening phenomenon also impacts gluons occurring in loop corrections to the pressure of cold quark matter, leading to contributions from the parametric scale αs1/2μB, starting at next-to-next-to-leading order (N2LO) in the strong coupling constant αs. At next-to-next-to-next-to-leading order (N3LO), interactions between these long-wavelength gluonic modes contribute to the pressure. These interaction corrections have recently been computed in Ref [1, 2], and the inclusion of these interactions slightly improves the convergence of the equation of state of cold quark matter. In these proceedings, we present these results and provide details summarizing how this lengthy calculation was performed.

Statistical mechanics of cold deconfined quark matter using quasiparticle model

2020 ◽  
Vol 35 (13) ◽  
pp. 2050064
Author(s):  
P. Simji
Keyword(s):  
Equation Of State ◽  
Statistical Mechanics ◽  
Quark Matter ◽  
Chemical Potential ◽  
Zero Temperature ◽  
Quark Star ◽  
Consistency Relation ◽  
Quasiparticle Model ◽  
Thermodynamical Consistency

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.

scholarly journals Holography and fermions at a finite chemical potentialThis paper was presented at the Theory CANADA 4 conference, held at Centre de recherches mathématiques, Montréal, Québec, Canada on 4–7 June 2008.

2009 ◽  
Vol 87 (3) ◽  
pp. 271-277 ◽  
Author(s):  
Moshe Rozali ◽  
Lionel Brits
Keyword(s):  
Fermi Surface ◽  
Nuclear Matter ◽  
Chemical Potential ◽  
Density Wave ◽  
Zero Temperature ◽  
Baryon Chemical Potential ◽  
Wave Instability ◽  
Large N ◽  
Holographic Qcd ◽  
Matter Phase

We review the Sakai–Sugimoto model of holographic QCD at zero temperature and finite chemical potential, comparing the results to those expected at large-Nc QCD, and those in a closely related holographic model. We find that as the baryon chemical potential is increased above a critical value, there is a phase transition to a nuclear matter phase, the details of which depend on the model. We argue that the nuclear matter phase is necessarily inhomogeneous to arbitrarily high density, which suggests an explanation of the “chiral density wave” instability of the quark Fermi surface in large-Nc QCD. Some details of the instanton distribution in the holographic dual are reminiscent of a Fermi surface. This short manuscript summarizes a talk given by M.R. at Theory CANADA 4 conference and is based largely (but not entirely) on the results of (Rozali et al. JHEP. 53, 01 (2008)).

Topological phase transition in asymmetric nuclear matter

2014 ◽  
Vol 23 (05) ◽  
pp. 1450031
Author(s):  
Tran Huu Phat ◽  
Nguyen Van Thu
Keyword(s):  
Phase Transition ◽  
Nuclear Matter ◽  
Critical Point ◽  
Fermi Liquid ◽  
Chemical Potential ◽  
Topological Phase ◽  
Baryon Chemical Potential ◽  
Asymmetric Nuclear Matter ◽  
First Order ◽  
Topological Phase Transition

Starting from an effective model of asymmetric nuclear matter we show that at finite temperature T and baryon chemical potential μB there exists a topological phase transition from state of non-Fermi liquid to that of Fermi liquid which is protected by winding numbers. At low μB the transition is first-order, then extends to a second-order phase transition at larger μB through a tri-critical point. The isospin dependences of the tri-critical point and the phase diagram in the (T, μB)-plane are established. The distinction between this type of phase transition and the similar phenomenon caused by the Silver Blaze property (SBP) at T = 0 is confirmed for isospin varying from 0 to 1. We reveal that the topological phase transition could emerge in a large class of nuclear theories.

Sign in / Sign up

Export Citation Format

Share Document