Testing leptonic SU(2) horizontal symmetry using neutrino mixings

AbstractAfter some preliminary arguments suggesting that neutrino mixings with inverted mass pattern may be easier to understand within the framework of a local horizontal symmetry SU(2)H acting on leptons, we construct a specific extension of the minimal supersymmetric standard model that implements the idea and analyze its predictions. We show that the horizontal symmetry leads to an experimentally testable relation between the neutrino parameters Ue3 and the ratio of solar and atmospheric mass difference squared, i.e., U2e3cos2θ⊙=(Δm2⊙/2Δm2A)+O(U4e3,(me/mμ)2). Taking the solar neutrino parameters inferred from present data at 99.7% confidence level, the above relation leads to a lower bound on Ue3⩾0.08 and an allowed region in the Ue3 and Δm2⊙/2Δm2A space which can be tested in proposed long baseline experiments