2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/148079We describe a perturbation expansion for the energy and wave function of a weakly bound particle in a short-range potential in one space dimension.7 pages (LaTeX) with 4 figures; requires prepictex, pictex, and postpictex. The LaTeX code has been made compatible with the archive's auto-postscript program; no changes have been made to the paperHigh Energy Physics - PhenomenologyQuantum Physicstext