%0 Journal Article
%A Brodsky, S. J
%A Peláez Sagredo, José Ramón
%A Toumbas, N.
%T Testing QCD with hypothetical tau leptons
%D 1999
%@ 1550-7998
%U https://hdl.handle.net/20.500.14352/59879
%X We construct new phenomenological tests of perturbative QCD by considering a hypothetical  au lepton of arbitrary mass which decays hadronically through the electromagnetic current. Its  adronic branching ratio can be computed directly as an integral over the e⁺e⁻ annihilation cross section ratio, R_ (e⁺e⁻). More generally, we can design a set of commensurate scale relations which test the applicability and self-consistency of leading twist QCD predictions by varying the weight function away from the form associated with the V-A decay of the physical τ . This method allows the wide range of R_(e⁺e⁻) data (or other similar observables which define an effective charge) to be used as renormalization scheme and scale invariant probes of QCD. [S0556-2821(99)05713-6].
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