Author/Authors :
K.G. Chetyrkin، نويسنده , , R. Harlander and M. Steinhauser، نويسنده , , J.H. Kühn، نويسنده , , M. Steinhauser، نويسنده ,
Abstract :
Three-loop QCD corrections to the vector current correlator are considered. The large momentum procedure is applied in order to evaluate mass corrections up to order (m2/q2)6. The inclusion of the first seven terms to the ratio R = σ(e+e− → hadrons)σ(e+e− → μ+μ−) leads to reliable predictions from the high-energy region down to relatively close to threshold.
