Vector mesons from tensor couplings in the NJL model

We propose to describe vector mesons in a pure quark model such as the one of Nambu and Jona-Lasinio by means of four point tensor interactions, but w ith vanishing vector and axial couplings. This becomes possible due to tens er-vector mixing at the one quark loop level. As a consequence a bound part icle with rho quantum numbers is generated. This has the advantage of avoid ing the A - pi mixing which is known to generate a wrong off-shell pion wav e function renormalization. In addition, there is no A(1) meson. We make ou r arguments quantitative by computing Euclidean correlators via dispersion relations and comparing with lattice QCD and random instanton model results . (C) 1998 Elsevier Science B.V. All rights reserved.