Until recently, the neutrino mixing pattern was wellapproximated by
tribimaximal mixing (TBM). The results from the Daya Bay and Reno
collaborations have called this paradigm into question and indicate
that the reactor angle theta13 is nonzero with about 5sigma
significance. Explaining the largeness of theta13 is now one of the
major challenges in neutrino model building. Motivated by the fact
that tribimaximal mixing is still a good prediction for the solar and
atmospheric mixing angles, we present a supersymmetric model with a T7
family symmetry (w/o any abelian factors) that gives TBM at leading
order. The particle content is that of the Standard Model plus two
flavon fields, and the effective Lagrangian contains all terms of mass
dimension <=6. We realize a large theta13 by considering the
nexttoleading order (NLO) corrections to the superpotential. In
general, the NLO corrections will not only increase theta13, but also
change the values of theta12 and theta23. By realizing our effective
Lagrangian as the lowenergy limit of a renormalizable, more
fundamental theory, we pick only those contributions that increase
theta13 and do not appreciably change the other two mixing angles. Our
model is minimal in the sense that T7 has only 21 elements and is thus
smaller than any A4xZN symmetry group for which TBM has been realized
so far.
