2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/37147In this pedagogic note, set as problem for the reader, it is shown how the existence of a maximum energy of a neutrino that appears at a given angle to the direction of its parent pion leads to a useful enhancment of neutrino flux in an off-axis beam.High Energy Physics - Experimenttext