Glueball in a chiral linear sigma model with vector mesons

We present a two-flavor linear sigma model with global chiral symmetry and (axial-)vector mesons as well as an additional glueball degree of freedom. We study the structure of the well-established scalar resonances f(0)(1370) and f(0)(1500): by a fit to experimentally known decay widths we find that f(0)(1370) is predominantly a (q) over barq state and f(0)(1500) is predominantly a glueball state. The overall phenomenology of these two resonances can be well described. Other assignments for our mixed quarkonium-glueball states are also tested, but turn out to be in worse agreement with the phenomenology. As a by-product of our analysis, the gluon condensate is determined.