2008/04/01 by D. V. Shirkov
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/s1547477108060010
published as Phys.Part.Nucl.Lett.5:489-493,2008 · 8 pages, 1 figure, submitted to Part. Nucl. Phys. Lett
arxiv created 2008/04/01 · openalex publication_date 2008/11/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/01
In quantum theory, physical amplitudes are usually presented in the form of a Feynman perturbation series in powers of coupling constant α. However, it is known that these amplitudes are not regular functions at α = 0. For QCD, we propose new sets of expansion parameters w k (α s ) that reflect singularity at α s = 0 and should be used instead of powers α . Their explicit form is motivated by the so-called Analytic Perturbation Theory. These parameters reveal saturation in a strong coupling case at the level α eff (α s 1) = w 1(α s 1) ∼ 0.5. They can be used for the quantitative analysis of divers low-energy amplitudes. We argue that this new picture with non-power sets of perturbation expansion parameters, as well as the saturation feature, is of a rather general nature.