出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：Duality Violations (DVs) is a nickname for the failure of the Operator Product Expansion to
describe QCD correlators on the physical axis. Using a physically motivated ansatz, a fit to the
spectral functions allows us to get a quantitative estimate for the amount of DVs present in t data.
The quality of the fit turns out to be better than expected. Since DVs have not been included in the
past in the determination of as, they amount to an additional theoretical error which we estimate
could be das(mt ) ∼ 0.003−0.010. Our ansatz satisfies, in particular, the 1st Weinberg sum rule,
which shows that this sum rule is not enough to force DVs to vanish.
