“…Indeed, extensive computations in lattice gauge theory support quark confinement and are able to describe quite in detail the behavior of the static quark potential. Recent studies [3,4,5,6,7] have shown, in particular, the presence of an intermediate region where the string tension of the linearly confining potential is proportional to the quadratic Casimir operator (of the color group); hence the name "Casimir scaling". However, as soon as the distance between the charges increases, at some point screening by gluons becomes energetically favored and Casimir scaling breaks down [6,8].…”