Neutrino Mass Spectra and $ u_{mu} - u_s$ Oscillations of Atmospheric Neutrinos

por Prof. A. Smirnov (ICTP-Trieste)

martes 21 abr. 1998 16:00 → 17:00 Europe/Madrid

Sala Seminarios (Dpto. de Fisica Teorica (UVEG))

Two natural spectra of the neutrino mass based on the see-saw mechanism with the intermediate mass scale and the GUT scale are considered. In addition, an existence of new light singlet fermion $\nu_s$ is suggested to solve the atmospheric neutrino problem. Properties of the $\nu_{\mu} - \nu_s$ oscillations of the atmospheric neutrinos are studied. In particular, it is shown that the parametric resonance occurs in the oscillations of neutrinos when they cross the core of the Earth. This leads to a peculiar zenith angle distribution of the upward-going muons which can be relevant for explanation of the MACRO, Baksan and Super-Kamiokande data.