Nontriviality of Abelian gauged Nambu-Jona-Lasinio models in four dimensions - art. no. 025001

We study a particular class of Abelian gauged Nambu-Jona-Lasinio models wit h global U-L(N) x U-R(N) symmetry, where N is the number of fermion flavors . We show, by treating the gauge interaction in the ladder approximation an d four-fermion interactions in the leading order of the 1/N expansion, that the renormalization-group beta function of the U(1) gauge coupling has ult raviolet stable fixed points for sufficiently large N. This implies the exi stence of a nontrivial continuum limit.