2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/219316We derive a closed, model space independent, expression for the electromagnetic correction factor $δ$ to the scattering length $a$ extracted from a hydrogenic atom with an extended charge to order $α^2$ and $a^3$ in the limit of a short ranged hadronic interaction.4 pages; PANIC02, XVIth Conference on Particles and Nuclei, Osaka, to appear in Nuclear Physics AHigh Energy Physics - Phenomenologytext