Computing the perturbative gluon condensate

Abstract

The normalization of the gluon condensate and of renormalon-related power corrections in QCD is computed under the assumption that their ``perturbative'' part dominates over any eventual extra contribution from the non-trivial vacuum. The calculation is performed in the infrared finite coupling framework, assuming an infrared fixed point is present in the perturbative coupling down to low values of N_f. The freezing perturbative coupling is reconstructed using a Banks-Zaks expansion approach. Parameter-free predictions of the low energy moments of the coupling, which determine the process-independent part of the power corrections, are obtained for a number of choices of the running coupling.

Comments: 16 pages, 2 figures, JHEP style. JHEP version: further comparison and discussion of the discrepancy with the standard SVZ procedure is given (mainly in section 4)