THE PERILS OF A 17 KEV NEUTRINO

Recent measurements of low Q-value beta decay spectra have again suggested the existence of a 17 KeV neutrino. Here we examine a large body of constraints, arising from astrophysics, cosmology, nuclear physics and elementary particle physics, on this particle. By comparing the derived bounds on its lifetime, decay modes and possible electromagnetic properties with a variety of model speculations on its nature, we conclude that such a particle is unlikely. Conversely, if such a neutrino were shown conclusively to exist, it would have profound implications for the nature of the symmetry breaking in the weak leptonic sector. It would most probably imply the existence of physical Goldstone bosons.