标题： $α_s$状态与展望（2018） 显示英文标题

标题： $α_s$ status and perspectives (2018)

摘要： 最新实验和理论进展在高精度确定强耦合常数$\alpha_s$方面进行了简要回顾。 六组可观测量：(i) 格点QCD数据，(ii) 强子$\tau$衰变，(iii) 深度非弹性$e^\pm p$数据和部分子分布函数（PDF）拟合， (iv)$e^+e^-$碰撞中的事件形状和喷注率，(v) Z玻色子强子衰变，以及(vi) pp碰撞中的顶夸克截面，用于提取当前世界平均值在Z玻色子质量处，$\alpha_s(m_Z^2) = 0.1181 \pm 0.0011$在下一阶下一阶下一阶（NNLO）或更高精度下的值。 最近基于新的格点研究，$R(s)$比值在$e^+e^-\to \mbox{hadrons}$中，更新的 PDF 拟合，$e^+e^-$碰撞中的能量-能量关联，$e^\pm p$碰撞中的喷注截面，以及 LHC 上的全部$pp\to t\bar{t}$截面，出现了更多的 NNLO 提取结果。 将这些新数据纳入世界平均值会使其中心值略有增加，并将其不确定性降低到$\alpha_s(m_Z^2) = 0.1183 \pm 0.0008$。 未来在高亮度$e^+e^-$机器中通过 W 和 Z 宇宙射线衰变、部分子碎片函数和光子$F_2(x,Q^2)$结构函数在$\gamma\gamma$碰撞中的未来$\alpha_s$提取前景——也进行了讨论。 显示英文摘要

摘要： The latest experimental and theoretical developments in the high-precision determination of the strong coupling $\alpha_s$ are briefly reviewed. Six groups of observables: (i) lattice QCD data, (ii) hadronic $\tau$ decays, (iii) deep-inelastic $e^\pm p$ data and parton distribution functions (PDF) fits, (iv) event shapes and jet rates in $e^+e^-$ collisions, (v) Z boson hadronic decays, and (vi) top-quark cross sections in pp collisions, are used to extract the current world-average at the Z pole mass, $\alpha_s(m_Z^2) = 0.1181 \pm 0.0011$ at next-to-next-to-leading-order (NNLO), or beyond, accuracy. Additional NNLO extractions have recently appeared based on new lattice studies, the $R(s)$ ratio in $e^+e^-\to \mbox{hadrons}$, updated PDF fits, energy-energy correlations in $e^+e^-$ collisions, jet cross sections in $e^\pm p$ collisions, and the full set of $pp\to t\bar{t}$ cross sections at the LHC. Inclusion of these new data into the world-average would slightly increase its value and reduce its uncertainty to $\alpha_s(m_Z^2) = 0.1183 \pm 0.0008$. Future $\alpha_s$ extraction perspectives with permille uncertainties at future high-luminosity $e^+e^-$ machines -- via W and Z hadronic decays, parton fragmentation functions, and photon $F_2(x,Q^2)$ structure function in $\gamma\gamma$ collisions -- are also discussed.