Ball Richard D, Carrazza Stefano, Debbio Luigi Del, Forte Stefano, Kassabov Zahari, Rojo Juan, Slade Emma, Ubiali Maria
1The Higgs Centre for Theoretical Physics, University of Edinburgh, JCMB, KB, Mayfield Rd, Edinburgh, Scotland EH9 3JZ UK.
2Theoretical Physics Department, CERN, 1211 Geneva, Switzerland.
Eur Phys J C Part Fields. 2018;78(5):408. doi: 10.1140/epjc/s10052-018-5897-7. Epub 2018 May 24.
We present a determination of the strong coupling constant based on the NNPDF3.1 determination of parton distributions, which for the first time includes constraints from jet production, top-quark pair differential distributions, and the distributions using exact NNLO theory. Our result is based on a novel extension of the NNPDF methodology - the correlated replica method - which allows for a simultaneous determination of and the PDFs with all correlations between them fully taken into account. We study in detail all relevant sources of experimental, methodological and theoretical uncertainty. At NNLO we find , showing that methodological uncertainties are negligible. We conservatively estimate the theoretical uncertainty due to missing higher order QCD corrections (N LO and beyond) from half the shift between the NLO and NNLO values, finding .
我们基于对部分子分布的NNPDF3.1确定给出了强耦合常数的测定结果，这首次纳入了来自喷注产生、顶夸克对微分分布以及使用精确NNLO理论的分布的约束。我们的结果基于NNPDF方法的一种新颖扩展——相关副本方法，该方法能够在充分考虑它们之间所有相关性的情况下同时确定强耦合常数和部分子分布函数（PDFs）。我们详细研究了实验、方法和理论不确定性的所有相关来源。在NNLO下，我们发现[具体数值]，这表明方法不确定性可忽略不计。我们保守地通过NLO和NNLO[具体数值]之间差值的一半来估计由于缺失高阶QCD修正（N³LO及更高阶）导致的理论不确定性，结果为[具体数值]。
