Chiral sum rules and vacuum condensates from tau-lepton decay data
نویسنده
چکیده
QCD finite energy sum rules, together with the latest updated ALEPH data on hadronic decays of the tau-lepton are used in order to determine the vacuum condensates of dimension d = 2 and d = 4. These data are also used to check the validity of the Weinberg sum rules, and to determine the chiral condensates of dimension d = 6 and d = 8, as well as the chiral correlator at zero momentum, proportional to the counter term of the O(p4) Lagrangian of chiral perturbation theory, L̄10. Suitable (pinched) integration kernels are introduced in the sum rules in order to suppress potential quark-hadron duality violations. We find no compelling indications of duality violations in the kinematic region above s ≃ 2.2GeV2 after using pinched integration kernels.
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