scholarly journals Crossover-model approach to QCD phase diagram, equation of state and susceptibilities in the 2+1 and 2+1+1 flavor systems

2017 ◽  
Vol 32 (36) ◽  
pp. 1750205 ◽  
Author(s):  
Akihisa Miyahara ◽  
Masahiro Ishii ◽  
Hiroaki Kouno ◽  
Masanobu Yahiro
Keyword(s):  
Phase Diagram ◽  
Equation Of State ◽  
Baryon Number ◽  
Entropy Density ◽  
Transition Line ◽  
Qcd Phase Diagram ◽  
Chemical Potentials ◽  
Number Formula ◽  
Crossover Transition ◽  
Production Probability

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.

scholarly journals Using the Linear Sigma Model with quarks to describe the QCD phase diagram and to locate the critical end point

2018 ◽  
Vol 172 ◽  
pp. 08002
Author(s):  
Alejandro Ayala ◽  
Jorge David Castaño-Yepes ◽  
José Antonio Flores ◽  
Saúl Hernández ◽  
Luis Hernández
Keyword(s):  
Phase Diagram ◽  
Critical Temperature ◽  
Sigma Model ◽  
Chemical Potential ◽  
Linear Sigma Model ◽  
Transition Line ◽  
Baryon Chemical Potential ◽  
First Order ◽  
Qcd Phase Diagram ◽  
Crossover Transition

We study the QCD phase diagram using the linear sigma model coupled to quarks. We compute the effective potential at finite temperature and quark chemical potential up to ring diagrams contribution. We show that, provided the values for the pseudo-critical temperature Tc = 155 MeV and critical baryon chemical potential μBc ≃ 1 GeV, together with the vacuum sigma and pion masses. The model couplings can be fixed and that these in turn help to locate the region where the crossover transition line becomes first order.

QCD Phase Diagram at Finite Baryon and Isospin Chemical Potentials

2011 ◽  
Author(s):  
T. Sasaki ◽  
Y. Sakai ◽  
H. Kouno ◽  
M. Yahiro ◽  
Atsushi Hosaka ◽  
...  
Keyword(s):  
Phase Diagram ◽  
Qcd Phase Diagram ◽  
Chemical Potentials

scholarly journals Baryon number fluctuations in the QCD phase diagram from Dyson-Schwinger equations

2019 ◽  
Vol 100 (7) ◽  
Author(s):  
Philipp Isserstedt ◽  
Michael Buballa ◽  
Christian S. Fischer ◽  
Pascal J. Gunkel
Keyword(s):  
Phase Diagram ◽  
Baryon Number ◽  
Qcd Phase Diagram

The compressed baryonic matter experiment at FAIR

Open Physics ◽  
2012 ◽  
Vol 10 (6) ◽  
Author(s):  
Peter Senger
Keyword(s):  
Phase Diagram ◽  
Phase Transitions ◽  
Equation Of State ◽  
High Energy ◽  
Baryonic Matter ◽  
Lepton Pairs ◽  
Chiral Phase ◽  
Qcd Phase Diagram ◽  
Compressed Baryonic Matter ◽  
Large Acceptance

AbstractThe Compressed Baryonic Matter (CBM) experiment will be one of the major scientific pillars of the future Facility for Antiproton and Ion Research (FAIR) in Darmstadt. The goal of the CBM research program is to explore the QCD phase diagram in the region of high baryon densities using high-energy nucleus-nucleus collisions. This includes the study of the equation-of-state of nuclear matter at high densities, and the search for the deconfinement and chiral phase transitions. The CBM detector is designed to measure both bulk observables with large acceptance and rare diagnostic probes such as charmed particles and vector mesons decaying into lepton pairs.

scholarly journals QCD phase diagram at finite baryon and isospin chemical potentials

2010 ◽  
Vol 82 (11) ◽  
Author(s):  
Takahiro Sasaki ◽  
Yuji Sakai ◽  
Hiroaki Kouno ◽  
Masanobu Yahiro
Keyword(s):  
Phase Diagram ◽  
Qcd Phase Diagram ◽  
Chemical Potentials

scholarly journals QCD phase diagram from chiral symmetry restoration: analytic approach at high and low temperature using the Linear Sigma Model with Quarks

2018 ◽  
Vol 64 (3) ◽  
pp. 302 ◽  
Author(s):  
Luis Hernandez ◽  
Alejandro Ayala ◽  
Saul Hernandez-Ortiz
Keyword(s):  
Phase Diagram ◽  
Chiral Symmetry ◽  
Low Temperatures ◽  
Sigma Model ◽  
Chemical Potential ◽  
Linear Sigma Model ◽  
Transition Line ◽  
Chiral Symmetry Restoration ◽  
Qcd Phase Diagram ◽  
End Point

We use the linear sigma model with quarks to study the QCD phase diagram from the point of view of chiral symmetry restoration. We compute the leading order effective potential for high and low temperatures and finite quark chemical potential, up to the contribution of the ring diagrams to account for the plasma screening effects. We fix the values of the model couplings using physical values for the input parameters such as  the vacuum pion and sigma masses, the critical temperature at vanishing quark chemical potential and the conjectured end point value of the baryon chemical potential of the transition line at vanishing temperature. We find that the critical end point (CEP) is located at low temperatures and high quark chemical potentials $(\mu^{\text{CEP}}>320\ {\mbox{MeV}},T^{\text{CEP}}<40\ {\mbox{MeV}})$.

scholarly journals Restoring canonical partition functions from imaginary chemical potential

2018 ◽  
Vol 175 ◽  
pp. 07027 ◽  
Author(s):  
V.G. Bornyakov ◽  
D. Boyda ◽  
V. Goy ◽  
A. Molochkov ◽  
A. Nakamura ◽  
...  
Keyword(s):  
Chemical Potential ◽  
Baryon Number ◽  
Partition Functions ◽  
Transition Line ◽  
Qcd Phase Transition ◽  
Qcd Phase Diagram ◽  
Sign Problem ◽  
Canonical Approach ◽  
Grand Canonical ◽  
Fugacity Expansion

Using GPGPU techniques and multi-precision calculation we developed the code to study QCD phase transition line in the canonical approach. The canonical approach is a powerful tool to investigate sign problem in Lattice QCD. The central part of the canonical approach is the fugacity expansion of the grand canonical partition functions. Canonical partition functions Zn(T) are coefficients of this expansion. Using various methods we study properties of Zn(T). At the last step we perform cubic spline for temperature dependence of Zn(T) at fixed n and compute baryon number susceptibility χB/T2 as function of temperature. After that we compute numerically ∂χ/∂T and restore crossover line in QCD phase diagram. We use improved Wilson fermions and Iwasaki gauge action on the 163 × 4 lattice with mπ/mρ = 0.8 as a sandbox to check the canonical approach. In this framework we obtain coefficient in parametrization of crossover line Tc(µ2B) = Tc(C−ĸµ2B/T2c) with ĸ = −0.0453 ± 0.0099.

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