Physical interpretation of the dressed Polyakov loop in the Nambu–Jona-Lasinio model

We investigate the rapid rise of the dressed Polyakov loop in the Nambu–Jona-Lasinio (NJL) model as a function of temperature. In QCD such a behavior is interpreted as a confinement-deconfinement phase transition. However, we demonstrate that in the NJL model this is simply a remnant of the chiral transition.

Figure 1

On the left panel the dPL as a function of temperature is shown as calculated from the approximation to the condensate (12), while the right panel provides the temperature derivative. The explicit value is normalized to the high temperature behavior, i.e., ${\tilde{\Sigma }}_1(T)={\Sigma }_1(T)/{\Sigma }_1(\infty )$.