Friedberg–Lee symmetry breaking and its prediction for θ13

We consider an effective Majorana neutrino mass operator with the Friedberg-Lee symmetry; i.e., it is invariant under the transformation v(alpha) -> v(alpha) + z (for alpha = e, mu, tau) 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 theta(13) in terms of two known angles: sin theta(13) = tan theta(12)vertical bar(1 - tan theta(23))/(1 + tan theta(23))vertical bar. The model can simply be generalized to accommodate CP violation and be combined with the seesaw mechanism. (c) 2007 Elsevier B.V. All rights reserved.