Friedberg-Lee Symmetry Breaking and Its Prediction for theta_13
arXiv:hep-ph/0611360 · doi:10.1016/j.physletb.2007.01.040
Abstract
We consider an effective Majorana neutrino mass operator with the Friedberg-Lee symmetry; i.e., it is invariant under the transformation ν_α-> ν_α+ z (for α= e, μ, Ï) with z being a space-time independent constant element of the Grassmann algebra. We show that this new flavor symmetry can be broken in such a nontrivial way that the lightest neutrino remains massless but an experimentally-favored neutrino mixing pattern is achievable. In particular, we get a novel prediction for the unknown neutrino mixing angle θ_13 in terms of two known angles: \sinθ_13 = \tanθ_12 |(1- \tanθ_23)/ (1+\tanθ_23)|. The model can simply be generalized to accommodate CP violation and be combined with the seesaw mechanism.
RevTex 9 pages, 2 PS figures. More discussions added. Version accepted for publication in Phys. Lett. B