文章基本信息

标题：The $\Lambda$-parameter in 3-flavour QCD and $\alpha_s(m_Z)$ by the ALPHA collaboration
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作者：M.Bruno ; M.Dalla Brida ; P.Fritzsch 等
期刊名称：PoS - Proceedings of Science
印刷版ISSN：1824-8039
出版年度：2016
卷号：256
DOI：10.22323/1.256.0197
语种：English
出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：We present results by the ALPHA collaboration for the $\Lambda$-parameter in 3-flavour QCD and the strong coupling constant at the electroweak scale, $\alpha_s(m_Z)$, in terms of hadronic quantities computed on the CLS gauge configurations. The first part of this proceedings contribution contains a review of published material~\cite{Brida:2016flw,DallaBrida:2016kgh} and yields the $\Lambda$-parameter in units of a low energy scale, $1/L_{\rm had}$. We then discuss how to determine this scale in physical units from experimental data for the pion and kaon decay constants. We obtain $\Lambda_{\overline{\rm MS}}^{(3)} = 332(14)\,{\rm MeV}$ which translates to $\alpha_s(M_Z)=0.1179(10)(2)$ if one uses the standard perturbative procedure to match between 3-, 4- and 5-flavour QCD.