Scalar Mesons, Glueballs, Instantons and the Glueball/Sigma

الأصل · EN

We include instanton effects in QCD sum rules for coupled scalar glueballs and mesons. We find a light glueball/sigma as in earlier studies without instantons, but in a lattice-type pure instanton model the light glueball/sigma is not found. In the 1-2 Gev region we now find that lightest I=0 meson, in the region of the fₒ(1370), has no direct glueball mixing, with the instanton loop replacing the glueball component. The lightest scalar mainly glueball in the region of the fₒ(1500) is sensitive to the choice of nonperturbative gluonic parameters.