Baikov P A, Chetyrkin K G, Kühn J H
Institute of Nuclear Physics, Moscow State University, Moscow 119899, Russia.
Phys Rev Lett. 2005 Jul 1;95(1):012003. doi: 10.1103/PhysRevLett.95.012003. Epub 2005 Jun 30.
The first complete calculation of the quadratic quark mass correction to the correlator of the two currents relevant for the strangeness-changing semihadronic tau-decay rate is presented including its real part at the four-loop level. This allows us to perform the extraction of the strange-quark mass m(s) from the decay width of the tau-lepton with full O(alpha3s) accuracy. In agreement with previous estimates, the newly computed alpha3s term proves to be rather large. This justifies inclusion of the similarly estimated alpha4s term in phenomenological analysis. Combined with an updated value of V us and an "improved" version of the renormalization group improvement of the perturbative series, this leads to an increase of the central value of m(s) by about 20% and a partial reduction of the theoretical uncertainty by about 50%.
给出了对与奇异改变半轻子τ衰变率相关的两个流的关联函数的二次夸克质量修正的首次完整计算，包括其四圈水平的实部。这使我们能够以完整的O(α3s)精度从τ轻子的衰变宽度中提取奇异夸克质量m(s)。与先前的估计一致，新计算的α3s项被证明相当大。这证明在唯象分析中包含类似估计的α4s项是合理的。结合Vus的更新值和微扰级数重整化群改进的“改进”版本，这导致m(s)的中心值增加约20%，理论不确定性部分降低约50%。
