Behavior of the effective QCD coupling α τ(s) at low scales

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Abstract

The hadronic decays of the τ lepton can be used to determine the effective charge ατ(m τ 2,) for a hypothetical τ lepton with a mass in the range 0<m τ,<mτ. This definition provides a fundamental definition of the QCD coupling at low mass scales. We study the behavior of α τ at low mass scales directly from first principles and without any renormalization-scheme dependence by looking at the experimental data from the OPAL Collaboration. The results are consistent with the freezing of the physical coupling at mass scales s = m τ 2, of order 1 GeV 2 with a magnitude α τ ∼0.9 ±0.1.

Detaljer

Författare
Externa organisationer
  • SLAC National Accelerator Laboratory
  • Max Planck Institut fur Physik (Werner-Heisenberg-Institut)
  • CIBER de Fisiopatología Obesidad y Nutricion (CIBEROBN)
  • Uppsala universitet, Historiska institutionen
Forskningsområden

Ämnesklassifikation (UKÄ) – OBLIGATORISK

  • Subatomär fysik
Originalspråkengelska
Artikelnummer055008
TidskriftPhysical Review D
Volym67
Utgivningsnummer5
StatusPublished - 2003 dec 1
PublikationskategoriForskning
Peer review utfördJa
Externt publiceradJa