Effective model for hot gluodynamics

Abstract

We consider an effective Lagrangian containing contributions from glueball and gluon degrees of freedom with a scale-invariant coupling between the two. The thermodynamic potential is calculated taking into account thermal fluctuations of both fields. The glueball mean field dominates at low temperature, while the high temperature phase is governed by low-mass gluonlike excitations. The model shows some similarities to the lattice results in the pure glue sector of QCD. In particular, it exhibits a strong first order phase transition at a critical temperature of approximately 265 MeV when reasonable parameters are taken.

Partial deconfinement in color superconductivity

“…In Section III we study the relevant features connected with the deconfining transition. We provide an economical criterion to estimate the critical temperature similar to the one extensively used in literature for the in vacuum Yang-Mills theories [17]. Finally using the Polyakov loop model adapted to the present case we show the phase transition to be likely second order.…”

“…Above this critical temperature the model is no longer applicable since new degrees of freedom like the unconfined gluons are expected to appear (see e.g. [17]) and we will briefly comment on their effects. An amusing feature of the model is that the critical temperature can be determined analytically.…”

“…At zero density importance sampling lattice simulations are able to provide vital information about the nature of the temperature driven phase transition for 2 and 3 colors Yang-Mills theories with and without matter fields (see [12] for a review). Different models [13,14,15,16,17,18,19,20,21,22,23,24,25,26] are used in literature to tackle/study the features of this phase transition from a theoretical stand point. Some models compute non zero temperature corrections for the glueball Lagrangian with or without elementary gluon degrees of freedom (the latter added to describe the deconfined side of the phase transition).…”

“…Here when Eq. (1) is adjusted to take into account the gluonic degrees of freedom the higher order (in loop) contributions are shown to be less than 10% (see [17]). We find that the deconfining/confining critical temperature is smaller than the critical temperature T 2SC for the superconductive state itself which is estimated to be T 2SC ≈ 0.57 ∆ with ∆ the 2SC gap [27].…”

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

“…[13], where the effective degrees of freedom are the dilaton field and constituent gluons which become massive via an interaction with the gluon condensate. However, the results obtained in Ref.…”