ON PERTURBATIVE CALCULABILITY OF THE COEFFICIENT FUNCTIONS OF CONDENSATES IN THE QCD SUM RULES

We calculate two-loop corrections to the coefficient functions of the condensates 〈G2〉0 and [Formula: see text] in the QCD sum rules for the light mesons in the vector, scalar and pseudoscalar channels, and three-loop corrections to the coefficient function of the condensate 〈G2〉0 in the (pseudo)scalar channel. We find that a renormalization-group analysis casts strong doubts on the feasibility of obtaining correct estimates for the coefficient functions via perturbation theory.