Violations of quark-hadron duality in low-energy determinations of αs

• Published in: The journal of high energy physics Vol. 2022; no. 7; pp. 145 - 42
• Main Authors: Pich, Antonio, Rodríguez-Sánchez, Antonio
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 26.07.2022; Springer Nature B.V; SpringerOpen
• Subjects: Chiral Lagrangian; Classical and Quantum Gravitation; Elementary Particles; Energy; High energy physics; Jhep 25th Anniversary Special Issue; JHEP ANNIVERSARY SPECIAL ISSUE; Mathematical models; Physics; Physics and Astronomy; Quantum Field Theories; Quantum Field Theory; Quantum Physics; Quarks; Relativity Theory; Semi-Leptonic Decays; Specific QCD Phenomenology; String Theory; Systematic errors; The Strong Coupling; Uncertainty; Violations; Specific QCD Phenomenology; The Strong Coupling; Semi-Leptonic Decays; Chiral Lagrangian
• ISSN: 1029-8479; 1029-8479
• DOI: 10.1007/JHEP07(2022)145

A bstract Using the spectral functions measured in τ decays, we investigate the actual numerical impact of duality violations on the extraction of the strong coupling. These effects are tiny in the standard α s ( m τ 2 ) determinations from integrated distributions of the hadronic spectrum with pinched weights, or from the total τ hadronic width. The pinched-weight factors suppress very efficiently the violations of duality, making their numerical effects negligible in comparison with the larger perturbative uncertainties. However, combined fits of α s and duality-violation parameters, performed with non-protected weights, are subject to large systematic errors associated with the assumed modelling of duality-violation effects. These uncertainties have not been taken into account in the published analyses, based on specific models of quark-hadron duality.