2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/203138We study the origin of the resonances associated with pole singularities of the scattering amplitude in the chiral unitary approach. We propose a "natural renormalization" scheme using the low-energy interaction and the general principle of the scattering theory. We develop a method to distinguish dynamically generated resonances from genuine quark states [Castillejo-Dalitz-Dyson (CDD) poles] using the natural renormalization scheme and phenomenological fitting. Analyzing physical meson-baryon scatterings, we find that the Lambda(1405) resonance is largely dominated by the meson-baryon molecule component. In contrast, the N(1535) resonance requires a sizable CDD pole contribution, while the effect of the meson-baryon dynamics is also important.RevTeX4, 14 pages, 4 figures, 4 tables, title changed by editors, final version to appear in Phys. Rev. CNuclear TheoryHigh Energy Physics - Phenomenologytext