Analytic Reconstruction of heavy-quark two-point functions at O(\alpha_s^3)

Abstract

Using a method previously developed, based on the Mellin-Barnes transform, we reconstruct the two-point correlators in the vector, axial, scalar and pseudoscalar channels from the Taylor expansion at q^2=0, the threshold expansion at q^2=4m^2 and the OPE at q^2\rightarrow -\infty, where m is the heavy quark mass. The reconstruction is analytic and systematic and is controlled by an error function which becomes smaller as more terms in those expansions are known.