Explorando a termodinâmica de modelos confinantes

Abstract

Establishing a description for confinement is not something simple. In order to try to understand a little about this phenomenon, we will explore the thermodynamics of a toy model that tries to describe it in terms of propagators with violation of positivity. In this work, “confinement” is always understood in the sense of positivity violation of the spectral function of the elementary fields. For simplicity, we will define a model for scalar fields with a momentum dependent and nonlocal mass term. One of our objectives is to verify the thermodynamic properties of the theory that describes such a model, in order to analyze possible inconsistencies. For this we use the functional formalism of Quantum Field Theory (QFT) at finite temperature, from which we obtain the partition function and, consequently, some thermodynamic variables such as pressure and entropy density. Then, we obtain the two-point function at finite temperature of the scalar field of the model, in order to study whether or not there is a restoration of positivity (hence, deconfinement, in our language).