Three Layers of Neutrinos
  In this letter we point out that in a class of models for spontaneous
R-parity breaking based on gauged B-L, the spectrum for neutrinos is quite
peculiar. We find that those models generally predict three layers of
neutrinos: one heavy sterile neutrino, two massive active neutrinos, and three
near massless (one active and two sterile) neutrinos.
