2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/39684A general approach to accounting for retardation effects in the long-range (confining) part of the quark-antiquark potential is presented. The charmonium and bottomonium mass spectra are calculated with the systematic account of relativistic and retardation effects and the one-loop radiative corrections. A good fit to available experimental data on the mass spectra is obtained.5 pages, JHEP class, Talk given at the Vth International Workshop "Heavy Quark Physics", Dubna, Russia, 6-8 April 2000High Energy Physics - Phenomenologytext