2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/160967A low-energy non-unitary leptonic mixing matrix is a generic effect of some theories of new physics accounting for neutrino masses. We show how the extra CP-phases of a general non-unitary matrix allow for sizeable CP-asymmetries in the $ν_μ\to ν_τ$ channel. This CP-asymmetries turns out to be an excellent probe of such new physics.4 pages, 2 figures, based on talk given at XLIIIrd Rencontres de MORIOND Electroweak Session, La Thuile, March 1-8, 2008High Energy Physics - Phenomenologytext