Determination of quark and gluon vacuum condensates from τ-lepton decay data

Abstract

The values of the gluon and four-quark vacuum condensates are estimated using recent experimental data on the semileptonic ?-lepton decays ??v?+n?, which determine the vector and axialvector hadronic spectral functions. An optimal estimate is achieved through a systematic combined use Finite Energy, Laplace and Gaussian transform QCD sum rules. As a byproduct, the values of the dimensiond=8 vacuum condensates in the vector and axial-vector channels are also estimated.