Chiral condensate and dressed Polyakov loop in the Nambu-Jona-Lasinio model

Journal Article · Sun Aug 01 04:00:00 EDT 2010 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.82.034015· OSTI ID:21432855

Mukherjee, Tamal K; Huang, Mei ^[1]; Chen, Huan ^[1]

---

1. Institute of High Energy Physics, Chinese Academy of Sciences, Beijing (China)

We investigate the chiral condensate and the dressed Polyakov loop or dual chiral condensate at finite temperature and density in the two-flavor Nambu-Jona-Lasinio model. The dressed Polyakov loop is regarded as an equivalent order parameter of deconfinement phase transition in a confining theory. We find the behavior of a dressed Polyakov loop in the absence of any confinement mechanism quite interesting. With only quark degrees of freedom present, it still shows an order parameter like behavior. It is found that in the chiral limit, the critical temperature for chiral phase transition coincides with that of the dressed Polyakov loop in the whole (T,{mu}) plane. In the case of explicit chiral symmetry breaking, it is found that the transition temperature for chiral restoration T{sub c}{sup {chi}} is smaller than that of the dressed Polyakov loop T{sub c}{sup D} in the low baryon density region where the transition is a crossover. With the increase of the current quark mass the difference between the two transition temperatures is found to be increasing. However, the two critical temperatures coincide in the high baryon density region where the phase transition is of first order. We give an explanation on the feature of T{sub c}{sup {chi}}=T{sub c}{sup D} in the case of 1st and 2nd order phase transitions, and T{sub c}{sup {chi}}<T{sub c}{sup D} in the case of crossover, and expect this feature is general and can be extended to full QCD theory. Our result might indicate that in the case of crossover, there exists a small region where chiral symmetry is restored, but the color degrees of freedom are still confined.

• OSTI ID: 21432855
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 3 Vol. 82; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BARYONS
CHIRAL SYMMETRY
CHIRALITY
COLOR MODEL
COMPOSITE MODELS
CONDENSATES
CRITICAL TEMPERATURE
DEGREES OF FREEDOM
DENSITY
DIMENSIONLESS NUMBERS
ELEMENTARY PARTICLES
FERMIONS
FIELD THEORIES
HADRONS
MASS
MATHEMATICAL MODELS
ORDER PARAMETERS
PARTICLE MODELS
PARTICLE PROPERTIES
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
QUANTUM CHROMODYNAMICS
QUANTUM FIELD THEORY
QUARK MODEL
QUARKS
SIMULATION
SYMMETRY
SYMMETRY BREAKING
THERMODYNAMIC PROPERTIES
TRANSITION TEMPERATURE