Constraints on the I=1 hadronic tau decay and e^+e^- --> hadrons data sets and implications for (g-2)_mu
Abstract
Sum rule tests are performed on the spectral data for (i) flavor 'ud' vector- current-induced hadronic tau decays and (ii) e^+ e^- hadroproduction, in the region below s~3-4 GeV^2, where discrepancies exist between the isospin- breaking-corrected charged and neutral current I=1 spectral functions. The tau data is found to be compatible with expectations based on high-scale alpha_s(M_Z) determinations, while the electroproduction data displays two problems. The results favor determinations of the leading order hadronic contribution to (g-2)_mu which incorporate hadronic tau decay data over those employing electroproduction data only, and hence a reduced discrepancy between experiment and the Standard Model prediction for (g-2)_mu.
Keywords
Cite
@article{arxiv.hep-ph/0504201,
title = {Constraints on the I=1 hadronic tau decay and e^+e^- --> hadrons data sets and implications for (g-2)_mu},
author = {Kim Maltman},
journal= {arXiv preprint arXiv:hep-ph/0504201},
year = {2009}
}
Comments
14 pages, 4 figures. Additional information: rationale for weight choices, impact of long-distance EM corrections on tau data, impact on EM spectral integral problems of replacement of 2 pi, 4 pi data by equivalent tau data. Version to appear in Physics Letters B