2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/192422A detailed investigation of the low-energy chiral expansion is presented within a model truncation of QCD. The truncation allows for a phenomenological description of the quark-quark interaction in a framework which maintains the global symmetries of QCD and permits a $1/N_c$ expansion. The model dependence of the chiral coefficients is tested for several forms of the quark-quark interaction by varying the form of the running coupling, $α(q^2)$, in the infrared region. The pattern in the coefficients that arises at tree level is consistent with large $N_c$ QCD, and is related to the model truncation.28 pages, Latex, 6 postscript figures available on request to frank@phys.washington.eduNuclear TheoryHigh Energy Physics - Phenomenologytext