Low-energy constants and condensates from ALEPH hadronic τ decay data

Abstract

We determine the NLO chiral low-energy constant L10r, and combinations C12r C61r+C80r, C13r-C62r+C81r, C61r, and C87r, of the NNLO chiral low-energy constants incorporating recently revised ALEPH results for the non-strange vector (V) and axial-vector (A) hadronic τ decay distributions and recently updated RBC/UKQCD lattice data for the non-strange V-A two-point function. In the MS scheme, at renormalization scale μ=770\ MeV, we find L10r=-0.00350(17), C12r+C61r+C80r=0.00237(16)\ GeV-2, C12r-C61r+C80r=-0.00056(15)\ GeV-2, C13r-C62r+C81r=0.00046(9)\ GeV-2, C61r=0.00146(15)\ GeV-2, and C87r=0.00510(22)\ GeV-2. With errors here at or below the level expected for contributions of yet higher order in the chiral expansion, the analysis exhausts the possibilities of what can be meaningfully achieved in an NNLO analysis. We also consider the dimension six and dimension eight coefficients in the operator product expansion in the V-A channel.

0

Discussion (0)

Sign in to join the discussion.

Loading comments…