2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/183988The K2K experiment has presented the first results on the observation of nu_mu. They show a depletion compared to the expectations and are consistent with neutrino oscillations with a mass-splitting in the range favoured by the Super-Kamiokande atmospheric neutrino measurements. Here we examine the extent by which the range of Delta m^2 obtained from the K2K measurements can vary due to the uncertainties in the flux, cross-section, and detector efficiency.8 pages LaTeX, 2 postscript figures, J. Phys. G. (to appear)High Energy Physics - PhenomenologyHigh Energy Physics - Experimenttext