Wilson loop for the stretched contours in vacuum fields and the small-distance behaviour of the interquark potential
The Wilson loop average for a stretched rectangle is calculated phenomenologically using the multipole expansion and the assumption that correlations in the QCD physical vacuum decrease with increase in separation. The result may be interpreted as an attractive interquark potential arising from gluonic vacuum fluctuations in addition to the Coulomb attraction. The first two terms in the expansion of the potential in powers of the interquark separation are calculated. The potential obtained can be applied to high levels of toponium.