PUB - Publikationen an der Universität Bielefeld

We study the effects of the ground state entropy of coloured quarks upon the bag pressure at low temperatures. The vacuum expectation values of the quark and gluon fields are used to express the interactions in the QCD ground state in the limit of low temperatures and chemical potentials. Apparently, the inclusion of this entropy in the equation of state provides the hadron constituents with an additional heat which causes a decrease in the effective latent heat inside the hadronic bag and consequently decreases the non-perturbative bag pressure. We have considered two types of baryonic bags, Delta and Omega(-). In both cases we have found that the bag pressure decreases with the temperature. On the other hand, when the coloured quark ground state entropy is not considered, the bag pressure as conventionally believed remains constant for finite temperature.