Fermion masses and mixing with tri-bimaximal in SO(10) with type-I   seesaw
  We study a class of models for tri-bimaximal neutrino mixing in SO(10) grand unified SUSY framework. Neutrino masses arise from both type-I and type-II seesaw mechanisms. We use dimension five operators in order to not spoil tri-bimaximal mixing by means of type-I contribution in the neutrino sector. We show that it is possible to fit all fermion masses and mixings including also the recent T2K result as deviation from the tri-bimaximal. 
Gianluca Blankenburg, Stefano Morisi
hep-ph