QUARK-ANTIQUARK RESONANCES IN THE NJL MODEL

The problem of the rho meson resonance solution in the extended NJL mo del is studied. It has been shown previously that the solution for the rho meson changes smoothly from a bound state to a ''virtual state'' when the vector channel attraction becomes too weak to support bound s tate solutions. We have found that together with these solutions a sep arate resonance branch appears which is not connected smoothly with th e bound state solutions. At small values of constituent quark mass, m similar to 200 MeV, it corresponds to the physical vector meson resona nce solution in the quark-continuum region. The a(1) and sigma resonan ces are also discussed. (C) 1997 Elsevier Science B.V.