Relativistic properties of the quark-antiquark potential
  The relativistic transformation properties of the heavy quark-antiquark interaction potential are considered in the framework of the relativistic quark model. A special attention is paid to the long-range (confining) contribution to the spin-independent part of qq bar interaction. The retardation effects are consistently taken into account. 
D. Ebert, R. N. Faustov and V. O. Galkin