2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/84574It is proved that a source of electromagnetic radiation cannot emit a diffraction-free beam at the wave zone. A Bessel $J_0$ $ϕ$-invariant beam does not hold even at the intermediate zone. These results negate claims published recently in the literature.12 pages, 1 figureClassical PhysicsGeneral Physicstext