Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, 1(2), Leninskie gory, Moscow 119234, Russian Federation.
Phys Rev Lett. 2012 Jun 1;108(22):222003. doi: 10.1103/PhysRevLett.108.222003. Epub 2012 May 31.
Corrections of order α(s)(4) for the axial singlet contributions for the decay rate of the Z boson into hadrons are evaluated in the limit of the heavy top quark mass. Combined with recently finished O(α(s)(4)) calculations of the nonsinglet corrections, the new results directly lead us to the first complete O(α(s)(4)) prediction for the total hadronic decay rate of the Z boson. The new O(α(s)(4)) term in Z-decay rate leads to a significant stabilization of the perturbative series, to a reduction of the theory uncertainty in the strong coupling constant α(s), as extracted from these measurements, and to a small shift of the central value.
在重顶夸克质量极限下，评估了 Z 玻色子衰变为强子的轴向单态贡献的α(s)(4)阶修正。与最近完成的非单态修正的 O(α(s)(4))计算相结合，新的结果直接导致了对 Z 玻色子总强子衰变率的第一个完整的 O(α(s)(4))预测。Z 衰变率中的新 O(α(s)(4))项导致微扰级数的显著稳定化，从这些测量中提取的强耦合常数α(s)的理论不确定性减小，以及中心值的小偏移。
