Quasiparticle description of lattice QCD thermodynamics

Abstract

We propose a novel quasiparticle interpretation of the equation of state of deconfined QCD at finite temperature. Using appropriate thermal masses, we introduce a phenomenological parametrization of the onset of confinement in the vicinity of the predicted phase transition. Lattice results of the energy density, the pressure and the interaction measure of pure SU (3) gauge theory are excellently reproduced. We find a relationship between the thermal energy density of the Yang-Mills vacuum and the chromomagnetic condensate B 2 T . Finally, an extension to QCD with dynamical quarks is discussed. Good agreement with lattice data for 2, 2+1 and 3 flavour QCD is obtained. We also present the QCD equation of state for realistic quark masses.

From QCD lattice calculations to the equation of state of quark matter

“…The result then reproduces the extrapolated data [7] on the lower side of the estimated error band; see the remark at the end of the last section. 4 In an alternative approach, instead of attributing the deviations from the free limit at smaller temperatures to the mass of the quasiparticles, a variable number of degrees of freedom is proposed in [16].…”

Dilepton emission rates from hot hadronic matter

“…In the present investigation, the space-time evolution of the strongly compressed hadronic matter formed in a relativistic heavy ion collision is considered in a mixed scenario of QGP and hadronic matter. The QGP is described within a quasiparticle picture [19] and the hadronic matter described in a Quantum Hadrodynamic framework including quantum fluctuation effects from the baryon and scalar meson sectors [20,21,22].…”

Evaporation of the gluon condensate: a model for pure gauge SU(3)c phase transition

“…More recently, it has been pointed out that the number of effective degrees of freedom (i.e. the gluon degeneracy of the system) can itself be temperature dependent [8,9].…”