2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/39804The prospects of measuring the leptonic angles and CP-odd phases at a {\em neutrino factory} are discussed in the scenario of three active plus one sterile neutrino, motivated by the $ν_μ\raw ν_e$ LSND signal. Sensitivity to the MNS mixing matrix angles at $O (10^{-3})$ is achieved with a 1 T detector at $\sim 1$ km from the source, whereas leptonic CP-violation can be measured through tau detection with a 1 kT detector at $\sim 100$ km.7 pages,Latex2e, 3 .eps figures. Talk given at NuFact00, 22-26 May, MontereyHigh Energy Physics - Phenomenologytext