Hadronic bound-states in SU(2) from Dyson--Schwinger Equations

By using the Dyson-Schwinger/Bethe-Salpeter formalism in Euclidean spacetime, we calculate the ground state spectrum of $J\leq 1$ hadrons in an SU(2) gauge theory with 2 fundamental fermions. We show that the rainbow-ladder truncation, commonly employed in QCD studies, is unsuitable for a description of an SU(2) theory. This we remedy by truncating at the level of the quark-gluon vertex Dyson-Schwinger equation in a diagrammatic expansion. Results obtained within this novel approach show good agreement with lattice studies. These findings emphasize the need to use techniques more sophisticated than rainbow-ladder when investigating generic strongly interacting gauge theories.Comment: 9 pages, 11 figure

On propagators and three-point functions in Landau gauge QCD and QCD-like theories

Recent progress in our studies of propagators and three-point functions in Landau gauge for QCD and QCD-like theories is presented. Special emphasis is put on the properties of the three-gluon vertex and the quark-gluon vertex. The effect of unquenching is investigated. Furthermore, an exploratory study for a large number of light flavours is described, from where clear evidence for the qualitative behaviour of propagators in the so-called conformal window can be extracted.Comment: 13 pages, 9 figures; Proceedings of the workshop QCD-TNT-III, ECT* Trento, Sept. 2-6, 2013; references update