On the Landau gauge matter-gluon vertex in scalar QCD in a functional approach

Abstract

Recently the quark-gluon vertex has been investigated in Landau gauge using a combined Dyson-Schwinger and nPI effective action approach. We present here a numerical analysis of a simpler system where the quarks have been replaced by charged scalar fields. We solve the coupled system of Dyson-Schwinger equations for the scalar propagator, the scalar-gluon vertex and the Yang-Mills propagators in a truncation related to earlier studies. The calculations have been performed for scalars both in the fundamental and the adjoint representation. A clear suppression of the Abelian diagram is found in both cases. Thus, within the used truncation the suppression of the Abelian diagram predominantly happens dynamically and is to a high degree independent of the colour structure. The numerical techniques developed here can directly be applied to the fermionic case.Comment: 8 pages, 4 figures, presented by MH at Excited QCD 2013, 3rd - 9th February 2013, Bjelasnica Mountain, Sarajevo, Bosnia-Herzegovin