We study an effect of the off-shellness of the quark and antiquark inside a heavy quarkonium system on IR renormalons contained in the perturbative computations of the quarkonium energy levels. We demonstrate that, when the off-shellness P 2 Q - m 2 Q ∼ α 2 Sm 2 Q is larger than m Q Λ QCD, renormalons in the energy levels as calculated in perturbative QCD are suppressed by a factor Λ QCD/(α 2 Sm Q) as compared to those in 2m pole + V QCD(r). In this case the residual O(Λ QCD renormalon has the same dimension as that of the leading gluon-condensate contribution.
|Number of pages
|Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
|Published - 2002 May 23