First-order chiral phase transition from a six-fermion instanton interaction

Abstract

We compute the first-order chiral phase transition for an instanton motivated quark model with a local six-quark interaction. In order to compare different solutions of the gap equation we compute the bosonic effective action—a two-particle irreducible free energy functional. We find that the first-order transition ends for a critical current quark mass, with continuous crossover for larger quark masses. Furthermore, we investigate different possible order parameters, including a color-octet condensate. We also compare our formalism with mean field theory.