Klijnsma Thomas, Bethke Siegfried, Dissertori Günther, Salam Gavin P
1Institute for Particle Physics, ETH Zurich, Zurich, Switzerland.
2Max-Planck-Institute of Physics, Munich, Germany.
Eur Phys J C Part Fields. 2017;77(11):778. doi: 10.1140/epjc/s10052-017-5340-5. Epub 2017 Nov 18.
We present a determination of the strong coupling constant using inclusive top-quark pair production cross section measurements performed at the LHC and at the Tevatron. Following a procedure first applied by the CMS Collaboration, we extract individual values of from measurements by different experiments at several centre-of-mass energies, using QCD predictions complete in NNLO perturbation theory, supplemented with NNLL approximations to all orders, and suitable sets of parton distribution functions. The determinations are then combined using a likelihood-based approach, where special emphasis is put on a consistent treatment of theoretical uncertainties and of correlations between various sources of systematic uncertainties. Our final combined result is .
我们展示了一种利用在大型强子对撞机（LHC）和万亿电子伏特加速器（Tevatron）上进行的包含性顶夸克对产生截面测量来确定强耦合常数的方法。遵循CMS合作组首次应用的程序，我们在几个质心能量下，利用在NNLO微扰理论中完备且补充了所有阶次的NNLL近似的量子色动力学（QCD）预言以及合适的部分子分布函数集，从不同实验的测量中提取出的各个值。然后使用基于似然性的方法对这些确定值进行组合，其中特别强调对理论不确定性以及各种系统不确定性来源之间的相关性进行一致处理。我们最终的组合结果是 。
