Gauge Nambu–Jona-Lasinio model as a low-energy approximation of QCD

For the Nambu–Jona-Lasinio model in the regime of dynamical symmetry breaking we formulate principles for selecting $4$-fermion models as a low-energy approximation of QCD. On their basis, by means of an effective potential, we consider the possibility of their intrinsic stabilization at a finite cutoff momentum $\Lambda$. In the framework of the approach, we investigate the influence of the gluon condensate on the parameters of the model and the effective Lagrangian in the low-energy region.