Two-Loop Gluon-Condensate Contributions To Heavy-Quark Current Correlators: Exact Results And Approximations

D. J. Broadhurst, P. A. Baikov, V. A. Ilyin +3

The coefficient functions of the gluon condensate $<G^2>$, in the correlators of heavy-quark vector, axial, scalar and pseudoscalar currents, are obtained analytically, to two loop…