2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/82189The nuclear method to discover Majorana neutrinos is the neutrinoless double $ β$ decay. An interesting alternative is offered by the inverse process, neutrinoless radiative double electron capture, accompanied by a photon emission. Two different mechanisms seem plausible: the magnetic type radiation by an initial electron and the resonant electric type radiation by the final atom. The physical background for these processes is calculated.5 pages,1 figure. submitted to Acta Phys.Pol.BNuclear Theorytext