RT Journal Article T1 Testing QCD with hypothetical tau leptons A1 Brodsky, S. J A1 Peláez Sagredo, José Ramón A1 Toumbas, N. AB 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]. PB Amer Physical Soc SN 1550-7998 YR 1999 FD 1999-08-01 LK https://hdl.handle.net/20.500.14352/59879 UL https://hdl.handle.net/20.500.14352/59879 LA eng NO ©1999 The American Physical Society. DS Docta Complutense RD 11 abr 2025