U(2) and maximal mixing of ν_μ

A U(2) flavor symmetry can successfully describe charged fermion masses and mixings, and suppress SUSY FCNC processes, making it a viable candidate for a theory of flavor. We show that a direct application of this i/(2) flavor symmetry automatically predicts a mixing of 45° for ν_μ⇒ν_s, where ν_s is a light, right-handed state. The introduction of an additional flavor symmetry acting on the right-handed neutrinos makes the model phenomenologically viable, explaining the solar neutrino deficit as well as the atmospheric neutrino anomaly, while giving a potential hot dark matter candidate and retaining the theory's predictivity in the quark sector.