  We study a number of models, based on a non-Abelian discrete group, that
successfully reproduce the simple and predictive Yukawa textures usually
associated with U(2) theories of flavor. These models allow for solutions to
the solar and atmospheric neutrino problems that do not require altering
successful predictions for the charged fermions or introducing sterile
neutrinos. Although Yukawa matrices are hierarchical in the models we consider,
the mixing between second- and third-generation neutrinos is naturally large.
We first present a quantitative analysis of a minimal model proposed in earlier
work, consisting of a global fit to fermion masses and mixing angles, including
the most important renormalization group effects. We then propose two new
variant models: The first reproduces all important features of the SU(5)xU(2)
unified theory with neither SU(5) nor U(2). The second demonstrates that
discrete subgroups of SU(2) can be used in constructing viable supersymmetric
theories of flavor without scalar universality even though SU(2) by itself
cannot.

High Energy Physics - Phenomenology