TTP09-17 Reconstruction of heavy quark current correlators at O(α_s³)

s</sub>³) > We construct approximate formulas for the O(&alpha;_s³) QCD contributions to vector, axial-vector, scalar and pseudo-scalar quark current correlators, which are valid for arbitrary values of momenta and masses. The derivation is based on conformal mapping and the Pad&eacute; approximation procedure and incorporates known expansions in the low energy, threshold and high energy regions. We use our results to estimate additional terms in these expansions.