Towards NNLO accuracy in the QCD sum rule for the kaon distribution amplitude

We calculate the O (alpha(S)) and O (alpha(2)(S)) gluon radiative corrections to the QCD sum rule for the first Gegenbauer moment a(1)(K) of the kaon light-cone distribution amplitude. The NNLO accuracy is achieved for the perturbative term and quark-condensate contributions to the sum rule. A complete factorization is implemented, removing logarithms of s-quark mass from the coefficients in the operator-product expansion. The sum rule with radiative corrections yields a(1)(K) (1 GeV) = 0.10 +/- 0.04. (C) 2008 Elsevier B.V. All rights reserved.