Updated determination of chiral couplings and vacuum condensates from hadronic tau decay data

Abstract

We analyze the lowest spectral moments of the left-right two-point correlation function, using all known short-distance constraints and the recently updated ALEPH V-A spectral function from tau decays. This information is used to determine the low-energy couplings L10 and C87 of chiral perturbation theory and the lowest-dimensional contributions to the Operator Product Expansion of the left-right correlator. A detailed statistical analysis is implemented to assess the theoretical uncertainties, including violations of quark-hadron duality.

Comments: 25 pages, 8 figures, Preprint numbers: IFIC/16-08 FTUV/16-0219