QCD color interactions between two quarks

We study the QCD color interactions between static two heavy quarks at zero temperature in a quenched SU(3) lattice gauge simulation: in addition to the standard singlet qq¯ potentials, we calculate octet qq¯ potentials, symmetric and antisymmetric qq potentials. It is shown that the antisymmetric qq channel behaves as a linearly rising potential at large quark separations. We further find that the qq¯ octet and qq symmetric channels have the complex dependence on the distance; at short distances they are repulsive forces, while at large distances, they show linearly rising feature. Ratio of string tensions between qq¯ singlet and qq antisymmetric potentials is described in terms of the Casimir factor.