Quasi-Dirac neutrinos in a model with local $B-L$ symmetry
  In a model with $B-L$ gauge symmetry, right-handed neutrinos may have exotic local $B-L$ charge assignment: two of them with $B-L=-4$ and the other one having $B-L=5$. Then, it is natural to accommodate the right-handed neutrinos with the same $B-L$ charge in a doublet of the discrete $S_3$ symmetry, and the third one in a singlet. If the Yukawa interactions involving right-handed neutrinos are invariant under $S_3$, the quasi-Dirac neutrino scheme arise naturally in this model. However, we will show how in this scheme it is possible to give a value for $\theta_{13}$ in agreement with the Daya Bay results. For example the $S_3$ symmetry has to be broken in the Yukawa interactions involving right-handed charged lepton. 
A. C. B. Machado and V. Pleitez
hep-ph