Scalar Glueball--Quarkonium Mixing and the Structure of the QCD Vacuum

Abstract

We use Ward identities of broken scale invariance to infer the amount of scalar glueball--$\bar{q}q$ meson mixing from the ratio of quark and gluon condensates in the QCD vacuum. Assuming dominance by a single scalar state, as suggested by a phase-shift analysis, we find a mixing angle $\gamma \sim 36^{\circ }$, corresponding to near-maximal mixing of the glueball and $\bar{s}s$ components.

7 pages, LaTeX