QUASI GOLDSTONE FERMION AS A STERILE NEUTRINO

The existence of sterile neutrinos is hinted by the simultaneous prese nce of diverse neutrino anomalies. We suggest that the quasi Goldstone fermions (QGF's) arising in supersymmetric theory as a result of spon taneous breaking of global symmetry such as the Peccei-Quinn symmetry or She lepton number symmetry can play the role of the sterile neutrin o. The smallness of the mass of QGF's (m(s) similar to 10(-3) -10 eV) can be related to the specific choice of superpotential or Kahler pote ntial (e.g., no-scale kinetic terms for certain superfields). Mixing o f QGF's with neutrinos implies R-parity violation. It can proceed via the coupling of QGF's with Higgs supermultiplets or directly with a le pton doublet. A model which accounts for the solar and atmospheric ano malies and dark matter is presented.