We study mesons in a Bethe-Salpeter-equation approach. In particular, we investigate
corrections to the rainbow-ladder truncation using a very simple model used
previously to study aspects and consequences of a dressed quark-gluon vertex in
mesons with equal-mass constituents[1,2]. Looking at the meson mass spectrum we
attempt to find patterns in - as well as to quantify - corrections to the
well-established rainbow-ladder truncation, generated in a systematic way. [1] A.
Bender, W. Detmold, C.D. Roberts, A. W. Thomas. Phys. Rev. C65 (2002) 065203 [2]
M.S. Bhagwat, A. Holl, A. Krassnigg, C.D. Roberts and P. C. Tandy. Phys.Rev. C70
(2004) 035205