scholarly journals On SU(3) Effective Models and Chiral Phase Transition

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
Abdel Nasser Tawfik ◽  
Niseem Magdy
Keyword(s):  
Phase Transition ◽  
Phase Diagram ◽  
Lattice Qcd ◽  
High Energy ◽  
Particle Model ◽  
Chiral Phase ◽  
Chiral Phase Transition ◽  
Thermal Models ◽  
Qcd Phase Diagram ◽  
Freeze Out

Sensitivity of Polyakov Nambu-Jona-Lasinio (PNJL) model and Polyakov linear sigma-model (PLSM) has been utilized in studying QCD phase-diagram. From quasi-particle model (QPM) a gluonic sector is integrated into LSM. The hadron resonance gas (HRG) model is used in calculating the thermal and dense dependence of quark-antiquark condensate. We review these four models with respect to their descriptions for the chiral phase transition. We analyze the chiral order parameter, normalized net-strange condensate, and chiral phase-diagram and compare the results with recent lattice calculations. We find that PLSM chiral boundary is located in upper band of the lattice QCD calculations and agree well with the freeze-out results deduced from various high-energy experiments and thermal models. Also, we find that the chiral temperature calculated from HRG is larger than that from PLSM. This is also larger than the freeze-out temperatures calculated in lattice QCD and deduced from experiments and thermal models. The corresponding temperature and chemical potential are very similar to that of PLSM. Although the results from PNJL and QLSM keep the same behavior, their chiral temperature is higher than that of PLSM and HRG. This might be interpreted due the very heavy quark masses implemented in both models.

scholarly journals Equilibrium statistical–thermal models in high-energy physics

2014 ◽  
Vol 29 (17) ◽  
pp. 1430021 ◽  
Author(s):  
Abdel Nasser Tawfik
Keyword(s):  
Lattice Qcd ◽  
Particle Production ◽  
Chemical Potential ◽  
Heavy Ion ◽  
High Energy ◽  
Linear Sigma Model ◽  
Particle Model ◽  
Heavy Ion Physics ◽  
Thermal Models ◽  
Freeze Out

We review some recent highlights from the applications of statistical–thermal models to different experimental measurements and lattice QCD thermodynamics that have been made during the last decade. We start with a short review of the historical milestones on the path of constructing statistical–thermal models for heavy-ion physics. We discovered that Heinz Koppe formulated in 1948, an almost complete recipe for the statistical–thermal models. In 1950, Enrico Fermi generalized this statistical approach, in which he started with a general cross-section formula and inserted into it, the simplifying assumptions about the matrix element of the interaction process that likely reflects many features of the high-energy reactions dominated by density in the phase space of final states. In 1964, Hagedorn systematically analyzed the high-energy phenomena using all tools of statistical physics and introduced the concept of limiting temperature based on the statistical bootstrap model. It turns to be quite often that many-particle systems can be studied with the help of statistical–thermal methods. The analysis of yield multiplicities in high-energy collisions gives an overwhelming evidence for the chemical equilibrium in the final state. The strange particles might be an exception, as they are suppressed at lower beam energies. However, their relative yields fulfill statistical equilibrium, as well. We review the equilibrium statistical–thermal models for particle production, fluctuations and collective flow in heavy-ion experiments. We also review their reproduction of the lattice QCD thermodynamics at vanishing and finite chemical potential. During the last decade, five conditions have been suggested to describe the universal behavior of the chemical freeze-out parameters. The higher order moments of multiplicity have been discussed. They offer deep insights about particle production and to critical fluctuations. Therefore, we use them to describe the freeze-out parameters and suggest the location of the QCD critical endpoint. Various extensions have been proposed in order to take into consideration the possible deviations of the ideal hadron gas. We highlight various types of interactions, dissipative properties and location-dependences (spatial rapidity). Furthermore, we review three models combining hadronic with partonic phases; quasi-particle model, linear sigma model with Polyakov potentials and compressible bag model.

scholarly journals TOPOLOGICAL STRING DEFECT FORMATION DURING THE CHIRAL PHASE TRANSITION

2002 ◽  
Vol 17 (08) ◽  
pp. 1149-1158 ◽  
Author(s):  
A. P. BALACHANDRAN ◽  
S. DIGAL
Keyword(s):  
Phase Transition ◽  
Heavy Ion Collisions ◽  
Transverse Energy ◽  
Defect Formation ◽  
Topological String ◽  
Heavy Ion ◽  
High Energy ◽  
Chiral Phase ◽  
Chiral Phase Transition ◽  
Ion Collisions

We extend and generalize the seminal work of Brandenberger, Huang and Zhang on the formation of strings during chiral phase transitions1 and discuss the formation of Abelian and non-Abelian topological strings during such transitions in the early universe and in the high energy heavy-ion collisions. Chiral symmetry as well as deconfinement are restored in the core of these defects. Formation of a dense network of string defects is likely to play an important role in the dynamics following the chiral phase transition. We speculate that such a network can give rise to non-azimuthal distribution of transverse energy in heavy-ion collisions.

scholarly journals Chiral phase transition in lattice QCD with Wilson quarks

1996 ◽  
Vol 71 (2) ◽  
pp. 337-341 ◽  
Author(s):  
Y. Iwasaki ◽  
K. Kanaya ◽  
S. Sakai ◽  
T. Yoshié
Keyword(s):  
Phase Transition ◽  
Lattice Qcd ◽  
Chiral Phase ◽  
Chiral Phase Transition
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