文章基本信息

标题：On the Extraction of the Strong Coupling Constant from Hadronic Tau Decay
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作者：D. BOITO ; O. Cata ; M. Golterman 等
期刊名称：PoS - Proceedings of Science
印刷版ISSN：1824-8039
出版年度：2011
卷号：2011
期号：Lattice2011
出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：The finite energy sum rule extraction of the strong coupling as from hadronic t decay data provides one of its most precise experimental determinations. As precision improves, small nonperturbative effects become increasingly relevant to both the central value and error. Here we present a new framework for this extraction employing a physically motivated model to accommodate violations of quark-hadron duality and enforcing a consistent treatment of higher-dimension operator product expansion contributions. Using 1998 OPAL data for the non-strange vector and axial-vector spectral functions, we find the nf = 3 values for as(m2t ) of 0:307(19) for fixed-order perturbation theory and 0:322(26) for contour-improved perturbation theory, corresponding to nf = 5 values for as(M2 Z) of 0:1169(25) and 0:1187(32), respectively.