Dynamical Symmetry Breaking In A Nambu-Jona-Lasinio Model And The Vacuum Structure

The vacuum structure for a Nambu-Jona -Lasinio type model is studied using the effective potential approach. The relevant degrees of freedom are taken to be two different sets of static, auxiliary fields with different symmetry properties, related by Fierz transformations in the action. The results are compared with the analysis of the Dyson-Schwinger equations in the one-loop approximation.