Pions as collective modes in the glueball condensate vacuum

The glueball condensate vacuum model is extended to incorporate the effects of light quarks. The resulting model exhibits spontaneous breaking of chiral SU(2)/sub f/ symmetry, and has a new kind of collective excitations, pions, which are distinct from the usual bag-model-type states. The dynamics of the pions are described by a σ model, and the parameters and f/sub π/ are calculated in terms of the radius R of the vacuum cells. The pion mass is related to and m/sub q/ via the usual partial conservation of axial-vector current relation. The model is extended to broken SU(3)/sub f/ using lowest-order chiral perturbation theory, and a mass formula for the eta' meson is obtained by including effects of the axial anomaly