2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/54977The annihilation channel is implemented into the front form calculations of the positronium spectrum presented in a previous publication. The effective Hamiltonian is calculated analytically. Its eigensolutions are obtained numerically. A complete separation of the dynamical and instantaneous part of the annihilation interaction is observed. We find the remarkable effect that the annihilation channel stabilizes the cutoff behavior of the spectrum.9 pp., ReVTeXHigh Energy Physics - Theorytext