Bimaximal Neutrino Mixing in a Zee-type Model with Badly Broken Flavor Symmetry

Abstract

A Zee-type neutrino mass matrix model with a badly broken horizontal symmetry SU(3)_H is investigated. By putting a simple ansatz on the symmetry breaking effects of SU(3)_H for transition matrix elements, it is demonstrated that the model can give a nearly bimaximal neutrino mixing with the ratio $\Delta m_{solar}^2/\Delta m_{atm}^2\simeq \sqrt{2}{m}_e/m_{\mu }=6.7\times 10^{-3}$, which are in excellent agreement with the observed data. In the near future, the lepton-number violating decay $Z\to {\mu }^{\pm }{\tau }^{\mp }$ will be observed.

Comments: 10 pages, no figures, a comment added