2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/125901Recent experimental observation by the CBELSA/TAPS collaboration indicates a downward mass shift of the $ω$ meson when put into a nuclear medium. Therefore it is worthwhile to take a look at theoretical approaches that can describe this mass shift. One such hadronic model was introduced by Klingl et al. (Nucl.Phys. A650:299-312). We will demonstrate that the heavy baryon limit approximation used there has no justification and returns wrong results. The results obtained with a correct treatment of the relevant $2π$-channel lead to unreasonable results for the $ω$ selfenergy in medium.9 Pages, 6 figures, To appear in the proceedings of 45th International Winter Meeting on Nuclear Physics (Bormio 2007), Bormio, Italy, 14-21 Jan 2007High Energy Physics - PhenomenologyNuclear Theorytext