The Mixing of Quarks and Leptons and Neutrino Degeneracy
  In drawing on an analogy with the flavor mixing observed in the quark sector we discuss a pattern of large flavor mixing angles in the lepton sector. Simple arguments based on a democratic symmetry and its violation in the lepton sector allow us to determine the flavor mixing matrix of leptons. The mixing angle relevant for solar neutrino oscillations is maximal (close to $45^{\circ}$), while the angle relevant for atmospheric neutrino oscillations is given by $\sin^2 2 \theta = 8/9$. The emerging pattern is consistent with the results of the solar and atmospheric neutrino experiments. 
Harald Fritzsch, Zhi-Zhong Xing