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We consider a general scheme for calculating the leptonic constant of heavyquarkonium QQ-bar in the framework of nonrelativistic quantum chromodynamics,NRQCD, operating as the effective theory of nonrelativistic heavy quarks. Weexplore the approach of static potential in QCD, which takes into account boththe evolution of effective charge in the three-loop approximation and thelinearly raising potential term, which provides the quark confinement. Theleptonic constants of bb-bar and cc-bar systems are evaluated by making use oftwo-loop anomalous dimension for the current of nonrelativistic quarks, wherethe factor for the normalization of matrix element is introduced in order topreserve the renormalization group invariance of estimates.Comment: 18 pages, 6 eps-figures, discussion and references added, vNRQCD  analysis considere

Leptonic constants of heavy quarkonia in a potential approach of nonrelativistic QCD