2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/182980Instability in the scalar channel of the fermion-antifermion scattering amplitude in massless QED_3 for number of flavours less than the critical value 128/3π^2 is demonstrated. The anomalous dimensions of gauge-invariant composite operators are determined to O(1/N). Exponentiation of the O(1/N) infrared logarithm is explicitly demonstrated by evaluating the contribution of the ladder diagrams.10 pages, uses axodraw.sty; minor additions, version to appear in Mod. Phys. Lett. AHigh Energy Physics - TheorySuperconductivityHigh Energy Physics - Phenomenologytext