2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/216402Infrared behaviour of the fermion propagator is examined by spectral representation.Assuming asymptotic states and using LSZ reduction formula we evaluate the the lowest order spectral function by definition.After exponentiation of it we derive the non perturbative propagator.It shows confinement and dynamical mass generation explicitly.7pages,latex,prepared for light-cone 2005,typos corrected,add referencesHigh Energy Physics - Theorytext