Year: 2026
Type: article
Abstract: Like the Gell-Mann–Low coupling α of QED, the effective charge α g 1 is a physical, observable-defined running coupling that can serve as the QCD coupling α s . It can be represented by an analytic form consistent with renormalization-group evolution, holographic light-front QCD (HLFQCD), and the world data on α s . As an observable, α g 1 has a physically relevant analytic structure that reflects the underlying partonic dynamics. It displays, in the long-distance regime, two imaginary conjugate singularities at Q 2 = ± i Λ s 2 , with Λ s the QCD scale. To connect this structure to confinement, we combine known general relations between α g 1 and the parton dressed propagators and vertices with a recent phenomenological representation of α g 1 within HLFQCD. Since, unlike vertices, propagators characterize a field variation between separate locations, the two singularities are assigned to the propagators. This results in the parton propagators displaying a long-distance behavior e − Λ s | x | / 2 | x | − 5 / 2 + d a where propagation is suppressed beyond distances of order 1/Λ s , as expected from confinement. This offers an intuitive interpretation of confinement as the suppression of QCD Green’s functions at long distance.
Source: Physics Letters B
Author: A. Deur
Institution: Thomas Jefferson National Accelerator Facility
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: diamond
Awards: G2562462929, G4531151473, G9000367620
OpenAlex ID: W7167575767