A Light Sterile Neutrino Based on the Seesaw Mechanism

D. Suematsu
2001 Progress of theoretical physics  
We propose a simple model of the neutrino mass matrix which can explain the solar and atmospheric neutrino problems in a 3(ν_L + ν_R) framework. Assuming that only two right-handed neutrinos are heavy and a Dirac mass matrix has a special texture, we construct a model with four light neutrinos. The favorable structure of flavor mixings and mass eigenvalues required by those neutrino deficits is realized as a result of the seesaw mechanism. Bi-maximal mixing structure might be obtainable in this
more » ... scheme. Since it contains a light sterile neutrino, it has a chance to explain the LSND result successfully. We consider an embedding of this scenario for the neutrino mass matrix into the SU(5) grand unification scheme using the Froggatt-Nielsen mechanism based on U(1)_F_1× U(1)_F_2. Both a small mixing angle MSW solution and a large mixing angle MSW solution are obtained for the solar neutrino problem depending on the charged lepton mass matrix.
doi:10.1143/ptp.106.587 fatcat:2ei6yljkmnarvcer53nc22nfem