SOLITONS IN THE NAMBU-JONA-LASINIO MODEL WITH VECTOR AND AXIAL MESONS

We study the effect of vector and axial isovector mesons in the soliton of the SU(2) NJL-model for static hedgehog configurations and on the chiral circle. The Lagrangian reproduces Sakurai's Universality and implements vector dominance through current-field identities. The parameters of the Lagrangian are fixed by means of a heat-kernel expansion up to second order taking the A-pi mixing into account. For the corresponding set of parameters we find solitons for constituent quark masses between M approximately 265 - 345 MeV which are much lower than those found without vector mesons. For the value M = 315 MeV which corresponds both to the KSFR relation 2g(rho)2f(pi)2 = m(rho)2 and the Weinberg sum rule m(A)2 = 2m(rho)2 the soliton has a clearly negative quark eigenvalue. The soliton mass is about 1100 MeV. For this choise of parameters the radius and axial coupling constant turn out to be too small.