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arXiv · 1606.06175

Scheme variations of the QCD coupling and hadronic $τ$ decays

Diogo Boito·Matthias Jamin·Ramon Miravitllas
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Abstract

The Quantum Chromodynamics (QCD) coupling, $α_s$, is not a physical observable of the theory since it depends on conventions related to the renormalization procedure. We introduce a definition of the QCD coupling, denoted by $\hatα_s$, whose running is explicitly renormalization scheme invariant. The scheme dependence of the new coupling $\hatα_s$ is parameterized by a single parameter $C$, related to transformations of the QCD scale $Λ$. It is demonstrated that appropriate choices of $C$ can lead to substantial improvements in the perturbative prediction of physical observables. As phenomenological applications, we study $e^+e^-$ scattering and decays of the $τ$ lepton into hadrons, both being governed by the QCD Adler function.

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Diogo Boito, Matthias Jamin, Ramon Miravitllas. 2016-09-14. Scheme variations of the QCD coupling and hadronic $τ$ decays. https://doi.org/10.1103/physrevlett.117.152001

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