2014/01/31 by Shotaro Imai, Hideo Suganuma
Physics and Astronomy · #Colored #Diquark #Formalism (music) #Hadron #High-Energy Particle Collisions Research #Mass generation #Quantum Chromodynamics and Particle Interactions #Quantum and Classical Electrodynamics #Quantum chromodynamics #Quark #Scalar (mathematics) #hep-ph
paper · pdf · doi:10.4236/jmp.2016.78073
published as J.Mod.Phys. 7 (2016) 790-805 · 17 pages, 15 figures
openalex publication_date 2016/01/01 · arxiv created 2016/02/25 · arxiv updated 2016/05/02 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
As a topic of “quantum color dynamics”, we study various mass generation of colored particles and gluonic dressing effect in a non-perturbative manner, using the Schwinger-Dyson (SD) formalism in (scalar) QCD. First, we review dynamical quark-mass generation in QCD in the SD approach as a typical fermion-mass generation via spontaneous chiral-symmetry breaking. Second, using the SD formalism for scalar QCD, we investigate the scalar diquark, a bound-state-like object of two quarks, and its mass generation, which is clearly non-chiral-origin. Here, the scalar diquark is treated as an extended colored scalar field, like a meson in effective hadron models, and its effective size R is introduced as a form factor. As a diagrammatical difference, the SD equation for the scalar diquark has an additional 4-point interaction term, in comparison with the single quark case. The diquark size R is taken to be smaller than a hadron, R ~ 1 fm, and larger than a constituent quark, R ~ 0.3 fm. We find that the compact diquark with R ~ 0.3 fm has a large effective mass of about 900 MeV, and therefore such a compact diquark is not acceptable in effective models for hadrons. We also consider the artificial removal of 3- and 4-point interaction, respectively, to see the role of each term, and find that the 4-point interaction plays the dominant role of the diquark self-energy. From the above two different cases, quarks and diquarks, we guess that the mass generation of colored particles is a general result of non-perturbative gluonic dressing effect.