2008/01/31 by Christian Kellermann, Christian S. Fischer · 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:10.1103/physrevd.78.025015
published as Phys.Rev.D78:025015,2008 · 25 pages, 4 figures; v2: minor clarifications added and typos corrected, version accepted by PRD
arxiv created 2008/06/25 · openalex publication_date 2008/07/11 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We consider the running coupling from the four-gluon vertex in Landau gauge, SU(Nc) Yang-Mills theory as given by a combination of dressing functions of the vertex and the gluon propagator. We determine these functions numerically from a coupled set of Dyson-Schwinger equations. We reproduce asymptotic freedom in the ultraviolet momentum region and find a coupling of order one at mid-momenta. In the infrared we find a nontrivial (i.e. nonzero) fixed point which is 3 orders of magnitude smaller than the corresponding fixed point in the coupling of the ghost-gluon vertex. This result explains why the Dyson-Schwinger and the functional renormalization group equations for the two point functions can agree in the infrared, although their structure is quite different. Our findings also support Zwanziger's notion of an infrared effective theory driven by the Faddeev-Popov determinant.