Freezing of QCD coupling affects the short distance static potential

A striking contradiction between the lattice short-range static potential (n(f) = 0) and standard perturbative potential is investigated in the framework of the background perturbation theory. With the use of the background coupling (alpha) over bar (B)(r) which contains the only background parameter, the mass m(B), fixed by the fine-structure fit in bottomonium, the lattice data are nicely explained without the introduction of an exotic short-range linear potential with a large "string tension" sigma*similar to1 GeV2. A significant difference between (alpha) over tilde (B)(r) and standard perturbative strong coupling alpha(V)(r) is found in the range 0.05 fm less than or similar torless than or similar to0.15 fm, while at larger distances, r>0.3 fm, (alpha) over tilde (B)(r) fast approaches the freezing value (alpha) over tilde (B)(infinity). Some problems concerning the strong-coupling properties at short and long distances are discussed and solutions are suggested.