2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/214401In these lecture notes we present mechanisms for the generation of Majorana neutrino masses and lepton mixing. We consider simple extensions of the Standard Model. Apart from a section about radiative mass generation, we put special emphasis on the seesaw mechanism and mu-tau interchange symmetry.23 pages, 3 figures, Lecture given at School on Particle Physics, Gravity and Cosmology, August 21 - September 2, 2006, Dubrovnik, CroatiaHigh Energy Physics - Phenomenologytext