The effective potential approach for composite operators is generalized to non-zero temperatures in order to derive the equation of state for pure SU(3) Yang-Mills fields. In the absence of external sources, this is nothing but the vacuum energy density. The key element of this derivation is the introduction of a temperature dependence into the expression for the bag constant. The non-perturbative analytical equation of state for gluon matter does not depend on the coupling constant, but instead introduces a dependence on the mass gap. This is responsible for the large-scale structure of the QCD ground state. The important thermodynamic quantities, such as the pressure, energy and entropy densities, etc, have been calculated. We show explicitly that the pressure may vary continuously around Tc = 266.5 MeV, whereas all other thermodynamic quantities undergo drastic changes at this point. The proposed analytical approach makes it possible to control for the first time the thermodynamics of gluon matter at low temperatures, below Tc. We reproduce the properties of the so-called fuzzy bag-type models through the presence of the mass gap in our equation of state. An analytic calculation of the gluon condensate is obtained as a function of temperature.
|Journal||Journal of Physics G: Nuclear and Particle Physics|
|Publication status||Published - Jun 9 2010|
ASJC Scopus subject areas
- Nuclear and High Energy Physics