2005/12/31 by D. V. Shirkov, Дмитрий Васильевич Ширков, A. V. Zayakin · 1 citation
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph
paper · pdf · doi:10.1134/s1063778807040205
published as Phys.Atom.Nucl.70:775-783,2007 · 12 pages, 0 figures. Model slightly modified to increase its accuracy. Numerical results upgraded, references added. The issue of scale uncertainty is discussed
arxiv created 2006/11/15 · openalex publication_date 2007/04/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Within ghost-free analytic perturbation theory (APT), devised in the last decade for low-energy QCD, simple approximations are proposed for three-loop analytic couplings and their effective powers, in both the spacelike (Euclidean) and timelike (Minkowskian) regions, accurate enough in a large range (1–100 GeV) of current physical interest. Effectiveness of the new model is illustrated by the example of γ(1S) decay, where a standard analysis gives α s(M γ) = 0.170 ± 0.004, which is inconsistent with the bulk of data on α s. Instead, we obtain α s mod (M γ) = 0.185 ± 0.005, which corresponds to α mod (M Z = 0.120 ± 0.002, which is close to the world-average value. The issue of scale uncertainty for γ decay is also discussed.