Violations of Quark-Hadron Duality in Low-Energy Determinations of $\alpha_s$
Autor: | Pich, Antonio, Rodríguez-Sánchez, Antonio |
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Rok vydání: | 2022 |
Předmět: | |
Druh dokumentu: | Working Paper |
DOI: | 10.1007/JHEP07(2022)145 |
Popis: | Using the spectral functions measured in $\tau$ decays, we investigate the actual numerical impact of duality violations on the extraction of the strong coupling. These effects are tiny in the standard $\alpha_s(m_\tau^2)$ determinations from integrated distributions of the hadronic spectrum with pinched weights, or from the total $\tau$ 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 $\alpha_s$ 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. Comment: 39 pages, 8 figures. References added. Published version |
Databáze: | arXiv |
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