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.
@article{arxiv.hep-ph/9704222,
title = {Mass Corrections to the Vector Current Correlator},
author = {K. G. Chetyrkin and R. Harlander and J. H. Kuehn and M. Steinhauser},
journal= {arXiv preprint arXiv:hep-ph/9704222},
year = {2009}
}
Comments
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/