Search

The skyrmion stability at finite isospin chemical potential is studied using the Skyrme Lagrangian with a finite pion mass . A critical value , above which a stable soliton does not exist, is found. We also explore some properties of the skyrmion as function of , i.e., the isoscalar rms radius and the isoscalar magnetic rms radius. Finally, considering the finite temperature effect on the skyrmion mass, we obtain a critical temperature , using the profile function of the skyrmion, above which the skyrmion mass does not have a minimum, which can be interpreted as the occurrence of the deconfinement phase transition.

We discuss some thermodynamical features of a QCD system within the two-flavor Polyakov loop extended Nambu–Jona-Lasinio (PNJL) model. Several thermodynamical quantities of interest (pressure, energy density, specific heat, speed of sound, etc.) are investigated and discussed in detail with two different forms of Polyakov loop potential. The effective coupling strength G incorporating a quark feedback (quark condensate) through operator product expansion is also discussed, as well as the relationship between color deconfinement and chiral phase crossover. We find that some thermodynamical quantities have quite different behavior for different Polyakov loop potentials. By changing the characteristic temperature T 0 of the pure Yang-Mills field, we find that when T 0 becomes small, color deconfinement might happen earlier than chiral phase crossover, while their relationship can be determined via some thermodynamical quantities. Furthermore, the behavior of the thermodynamical quantities is quite different in the two different forms of Polyakov loop potential studied. Especially, one of the potentials, specific heat, has two peaks, which correspond to color deconfinement and chiral phase crossover respectively. This interesting phenomenon may shed some light on whether the inflection points of the chiral condensate and deconfinement transitions happen at the same temperature or not for lattice QCD and experimental studies.