Constraints on the I=1 hadronic τ decay and e+e−→hadrons data sets and implications for (g−2)μ

Sum rule tests are performed on the spectral data for (i) flavor ud vector-current-induced hadronic τ decays and (ii) e+e− hadroproduction, in the region below s∼3-4GeV2, where discrepancies exist between the isospin-breaking-corrected charged and neutral current I=1 spectral functions. The τ data is found to be compatible with expectations based on high-scale αs(MZ) determinations, while the electroproduction data displays two problems. The results favor determinations of the leading order hadronic contribution to (g−2)μ which incorporate hadronic τ decay data over those employing electroproduction data only, and hence a reduced discrepancy between experiment and the Standard Model prediction for (g−2)μ.