Effective degrees of freedom and gluon condensation in the high temperature deconfined phase

Journal Article · Tue May 15 04:00:00 EDT 2007 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.75.054901· OSTI ID:20995305

Castorina, P; Mannarelli, M ^[1]

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1. Dipartimento di Fisica, Universita di Catania, Catania, Italia and INFN Sezione di Catania, Catania (Italy)

The equation of state and the properties of matter in the high temperature deconfined phase are analyzed by a quasiparticle approach for T>1.2T{sub c}. In order to fix the parameters of our model we employ the lattice QCD data of energy density and pressure. First we consider the pure SU(3) gluon plasma and it turns out that such a system can be described in terms of a gluon condensate and of gluonic quasiparticles whose effective number of degrees of freedom and mass decrease with increasing temperature. Then we analyze QCD with finite quark masses. In this case the numerical lattice data for energy density and pressure can be fitted assuming that the system consists of a mixture of gluon quasiparticles, fermion quasiparticles, boson correlated pairs (corresponding to in-medium mesonic states) and gluon condensate. We find that the effective number of boson degrees of freedom and the in-medium fermion masses decrease with increasing temperature. At T{approx_equal}1.5T{sub c} only the correlated pairs corresponding to the mesonic nonet survive and they completely disappear at T{approx_equal}2T{sub c}. The temperature dependence of the velocity of sound of the various quasiparticles, the effects of the breaking of conformal invariance and the thermodynamic consistency are discussed in detail.

• OSTI ID: 20995305
• Journal Information: Physical Review. C, Nuclear Physics, Journal Name: Physical Review. C, Nuclear Physics Journal Issue: 5 Vol. 75; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
CONFORMAL INVARIANCE
DEGREES OF FREEDOM
ENERGY DENSITY
EQUATIONS OF STATE
GLUON CONDENSATION
GLUONS
QUANTUM CHROMODYNAMICS
QUASI PARTICLES
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0400-1000 K