String tension and plaquette-plaquette correlation from QCD sum rules

Abstract

Using a sum rule-like technique, the string tension is computed in both the fundamental and adjoint representations. This method leads to results which seem to be independent of the shape of the Wilson loops, as they should. The same approach allows to obtain an estimate for both the mass gap (or O ++ glueball mass), m g =(0.8±0.2) GeV, and the typical confinement radius, R ∼ 0.8 fm.