2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/87818An interpretation of the ``halo problem'' in accelerators based on quantum-like diffraction is given. Comparison between this approach and the others based on classical mechanics equations is discussed.7 pages. To appear in Proceedings of the 6th International Conference on Squeezed States and Uncertainty Relations, (ICSSUR'99), 24-29 May 1999, Napoli, ITALY, (NASA Conference Publication Series). http://www.pd.infn.it/~khan/ and http://www.pd.infn.it/~pusterla/Accelerator PhysicsOpticsQuantum Physicstext