2009/12/08 by Thomas D. Cohen, Daniel L. Shafer, D. Shafer +1 · 1 citation
Mathematics · Physics and Astronomy · #Baryon #High-Energy Particle Collisions Research #Mathematics #Particle physics #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #Quantum chromodynamics #hep-ph
paper · pdf · doi:10.1103/physrevd.81.036006
published as Phys.Rev.D81:036006,2010 · 9 pages, 9 pdf figures, ReVTeX with pdflatex
arxiv created 2009/12/08 · openalex publication_date 2010/02/11 · arxiv updated 2014/11/20 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
QCDAS, a variant of large Nc QCD in which quarks transform under the color two-index antisymmetric representation, reduces to standard QCD at Nc=3 and provides an alternative to the usual large Nc extrapolation that uses fundamental representation quarks. Previous strong plausibility arguments assert that the QCDAS baryon mass scales as Nc2; however, the complicated combinatoric problem associated with quarks carrying two color indices impeded a complete demonstration. We develop a diagrammatic technique to solve this problem. The key ingredient is the introduction of an effective multigluon vertex: a ``traffic circle'' or roundabout diagram. We show that arbitrarily complicated diagrams can be reduced to simple ones with the same leading Nc scaling using this device, and that the leading contribution to baryon mass does, in fact, scale as Nc2.