2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/41394The basics of neutrino oscillations is presented. Existing evidences of neutrino oscillations, obtained in the atmospheric and solar neutrino experiments, are considered. The new CHOOZ bound on the element $|U_{e3}|^{2}$, obtained from the three-neutrino analysis of the data, is discussed. Decoupling of neutrino oscillations in the solar neutrino range of $Δm^{2}$ is considered.Lectures at Corfu Summer Institute on Elementary Particle Physics, Corfu, 31.8 - 20.9. 2001High Energy Physics - Phenomenologytext