Pion properties in the 1/N-c-corrected NJL model

We investigate the effect of mesonic fluctuations on the pion propagator in the Nambu-Jona-Lasinio (NJL) model by explicitly taking into account 1/N-c -corrections. Because of the non-renormalizability of the model we have to regularize the meson loops with an independent cutoff parameter Lambda(M). Whereas for moderate values of Lambda(M) the pion properties change only qu antitatively we encounter strong instabilities for larger Values of Lambda( M). (C) 2000 Published by Elsevier Science B.V. All rights reserved.