Mass Corrections to the Vector Current Correlator

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 $(m^2/q^2{)}^6$. The inclusion of the first seven terms to the ratio $R=\ddot{I}ƒ(e^{+}{e}^{-}\to hadrons)/\ddot{I}ƒ(e^{+}{e}^{-}\to \hat{I}{¼}^{+}\hat{I}{¼}^{-})$ leads to reliable predictions from the high energy region down to relatively close to threshold.

16 pages, LaTeX, 11 postscript figures. The complete paper, including figures, is also available via anonymous ftp at ftp://ttpux2.physik.uni-karlsruhe.de/ , or via www at http://www-ttp.physik.uni-karlsruhe.de/cgi-bin/preprints/