THE QCD PHASE DIAGRAM FOR SMALL CHEMICAL POTENTIALS

We construct a simple model for describing the hadron–quark crossover transition by using lattice QCD (LQCD) data in the [Formula: see text] flavor system, and draw the phase diagram in the [Formula: see text] and [Formula: see text] flavor systems through analyses of the equation of state (EoS) and the susceptibilities. In the present hadron–quark crossover (HQC) model, the entropy density [Formula: see text] is defined by [Formula: see text] with the hadron-production probability [Formula: see text], where [Formula: see text] is calculated by the hadron resonance gas model that is valid in low temperature [Formula: see text] and [Formula: see text] is evaluated by the independent quark model that explains LQCD data on the EoS in the region [Formula: see text] for the [Formula: see text] flavor system and [Formula: see text] for the [Formula: see text] flavor system. The [Formula: see text] is determined from LQCD data on [Formula: see text] and susceptibilities for the baryon-number [Formula: see text], the isospin [Formula: see text] and the hypercharge [Formula: see text] in the [Formula: see text] flavor system. The HQC model is successful in reproducing LQCD data on the EoS and the flavor susceptibilities [Formula: see text] for [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] in the [Formula: see text] flavor system, without changing the [Formula: see text]. We define the hadron–quark transition temperature with [Formula: see text]. For the [Formula: see text] flavor system, the transition line thus obtained is almost identical in [Formula: see text], [Formula: see text], [Formula: see text] planes, when the chemical potentials [Formula: see text] [Formula: see text] are smaller than 250 MeV. This [Formula: see text] approximate equivalence is also seen in the [Formula: see text] flavor system. We plot the phase diagram also in [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] planes in order to investigate flavor dependence of transition lines. In the [Formula: see text] flavor system, [Formula: see text] quark does not affect the [Formula: see text] flavor subsystem composed of [Formula: see text], [Formula: see text], [Formula: see text]. Temperature dependence of the off-diagonal susceptibilities and the [Formula: see text] show that the transition region at [Formula: see text] is [Formula: see text] for both the [Formula: see text] and [Formula: see text] flavor systems.

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QCD phase diagram at finite baryon and isospin chemical potentials

Physical Review D ◽

10.1103/physrevd.82.116004 ◽

2010 ◽

Vol 82 (11) ◽

Cited By ~ 37

Author(s):

Takahiro Sasaki ◽

Yuji Sakai ◽

Hiroaki Kouno ◽

Masanobu Yahiro

Keyword(s):

Phase Diagram ◽

Qcd Phase Diagram ◽

Chemical Potentials

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Chiral magnetic properties of QCD phase-diagram

The European Physical Journal A ◽

10.1140/epja/s10050-021-00501-z ◽

2021 ◽

Vol 57 (6) ◽

Author(s):

Abdel Nasser Tawfik ◽

Abdel Magied Diab

Keyword(s):

Magnetic Field ◽

Phase Diagram ◽

Magnetic Susceptibility ◽

Degrees Of Freedom ◽

Linear Sigma Model ◽

Critical Temperatures ◽

Magnetic Catalysis ◽

Qcd Phase Diagram ◽

Hadron Phase ◽

Chemical Potentials

AbstractThe QCD phase-diagram is studied, at finite magnetic field. Our calculations are based on the QCD effective model, the SU(3) Polyakov linear-sigma model (PLSM), in which the chiral symmetry is integrated in the hadron phase and in the parton phase, the up-, down- and strange-quark degrees of freedom are incorporated besides the inclusion of Polyakov loop potentials in the pure gauge limit, which are motivated by various underlying QCD symmetries. The Landau quantization and the magnetic catalysis are implemented. The response of the QCD matter to an external magnetic field such as magnetization, magnetic susceptibility and permeability has been estimated. We conclude that the parton phase has higher values of magnetization, magnetic susceptibility, and permeability relative to the hadron phase. Depending on the contributions to the Landau levels, we conclude that the chiral magnetic field enhances the chiral quark condensates and hence the chiral QCD phase-diagram, i.e. the hadron-parton phase-transition likely takes place, at lower critical temperatures and chemical potentials.

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The QCD phase diagram at nonzero baryon, isospin and strangeness chemical potentials: results from a hadron resonance gas model

Physics Letters B ◽

10.1016/j.physletb.2004.11.018 ◽

2005 ◽

Vol 605 (1-2) ◽

pp. 129-136 ◽

Cited By ~ 32

Author(s):

D. Toublan ◽

John B. Kogut

Keyword(s):

Phase Diagram ◽

Qcd Phase Diagram ◽

Chemical Potentials

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Roberge–Weiss phase transition and QCD phase diagram in the (2 + 1) flavor Polyakov quark meson model

Modern Physics Letters A ◽

10.1142/s0217732319500111 ◽

2019 ◽

Vol 34 (02) ◽

pp. 1950011

Author(s):

Xiu-Fei Li

Keyword(s):

Phase Transition ◽

Phase Diagram ◽

Chemical Potential ◽

Polyakov Loop ◽

Effective Model ◽

Thermodynamic Quantities ◽

Qcd Phase Diagram ◽

Chemical Potentials

The Roberge–Weiss (RW) phase transition of (2 + 1) flavor QCD at imaginary quark chemical potentials [Formula: see text] is investigated by employing the Polyakov loop extended Quark Meson model (PQM), where [Formula: see text] is temperature, and [Formula: see text] is a dimensionless chemical potential. We calculate some thermodynamic quantities and draw the phase diagram. This work can be considered as a supplement of studying the RW transition by using the effective model.

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