The static Qanti Q force from instanton gas and numerical lattice calculations

From the comparison of lattice Monte Carlo predictions for the force between infinitely heavy quarks with the instanton gas results in the cases of SU(2) and SU(3) the typical instanton scale sizes are determined. We present our SU(3) Yang-Mills MC data for different ratios of Wilson loops and establish the value Λsub(L)=(0.007+-0.001) √sigma for the string tension. The instanton mediated force follows the lattice data inside a small-distance region (up to approx. equal to0.3 fm), where the data obviouly disagree with the perturbative as well as with the phenomenologically known Qanti Q force. We argue that the disagreement with the latter is connected with the idealization of quarks at rest rather than with the absence of virtual light quark pairs. (orig.)