Gluonic content of the scalar meson nonet in a scaled effective Lagrangian

A scaled SU(3) Nambu-Jona-Lasinio Lagrangian is used to compute the mass of the nine scalar mesons in the vacuum and the mass of the glueball. This chiral model provides a gluonic content to the scalar mesons as well as a quark content to the glueball. It is shown that a suitable choice of the vacuum gluon condensate allows reproduction of the experimental masses of the scalar mesons except for K*0(1430). This choice corresponds to a weak coupling between the gluon and quark condensates, giving f0(1500) or fJ(1710) which is nearly a pure glueball.