Phenomenological Tests of Supersymmetric A_4 Family Symmetry Model of Neutrino Mass

Abstract

Recently Babu, Ma and Valle proposed a model of quark and lepton mixing based on $A_4$ symmetry. Within this model the lepton and slepton mixings are intimately related. We perform a numerical study in order to derive the slepton masses and mixings in agreement with present data from neutrino physics. We show that, starting from three-fold degeneracy of the neutrino masses at a high energy scale, a viable low energy neutrino mass matrix can indeed be obtained in agreement with constraints on lepton flavour violating $\hat{I}¼$ and $\ddot{I}„$ decays. The resulting slepton spectrum must necessarily include at least one mass below 200 GeV which can be produced at the LHC. The predictions for the absolute Majorana neutrino mass scale $m_0\ge 0.3$ eV ensure that the model will be tested by future cosmological tests and ${\hat{I}}^2{\hat{I}}_{0\hat{I}½}^2$ searches. Rates for lepton flavour violating processes ${\ell }_j\to {\ell }_i+{\hat{I}}^3$ in the range of sensitivity of current experiments are typical in the model, with BR$(μ\to e γ) \gsim 10^{-15}$ and the lower bound BR$(\ddot{I}„\to \hat{I}¼{\hat{I}}^3)>10^{-9}$. To first approximation, the model leads to maximal leptonic CP violation in neutrino oscillations.

23 pages, 7 figures