Electrical neutrality and pion modes in the two flavor PNJL model

Understand

We study the phase diagram and the pion modes in the electrically neutral two flavor PNJL model.

• One of the main result of this paper is that when electrical neutrality is required, pions do not condense in the ground state of the model: the isospin chemical potential $\mu_I = -\mu_e/2$ is always smaller than the value required for pion condensation to occur.
• Moreover we investigate on the pions and $\sigma$ mass spectra.
• We find that the qualitative behavior of the masses resembles that obtained in the NJL model.