Meson loop corrections to the NJL model

Abstract

We present a symmetry preserving approach to 1=N (N being the number of colors) corrections in the Nambu-Jona-Lasinio model. This is achieved through an explicit 1=N expansion where N is considered as a free parameter. Veri cation and use of the pertinent Ward identity to the next to leading order in 1=N is made in obtaining the Goldberger-Treiman relation. Although the present results are not new, the approach may be useful for deriving higher (than one loop) corrections to the NJL model in a systematic way.