Strong decays of a scalar glueball in a scale-invariant chiral quark model

An effective meson Lagrangian including a scalar glueball is constructed on the basis of U(3)×U(3) chiral symmetry. The glueball is introduced in the meson Lagrangian by using the principle of scale invariance of an effective Lagrangian and the dilaton model. The singlet-octet mixing of scalar-meson states is described by means of the ’t Hooft interaction. The contribution of scalar and pseudoscalar anomalies to the breakdown of scale invariance is taken into account. The mixing of quarkonia with the glueball is described. The mass spectrum of scalar mesons, together with the glueball, and also their strong decay widths are calculated. From a comparison of the results with experimental data, it follows that f0(1500) is rather a glueball, whereas f0(1710) is a quarkonium. This is in accord with the results obtained in our previous study, where radially excited scalar-meson states were described. It is shown that the ρ meson plays an important role in the description of glueball decays.