Small Violation of Universal Yukawa Coupling and Neutrino Large Mixing

抄録

We assume the universal Yukawa coupling (democratic mass matrix) with small violations for quark , charged lepton and neutrino masses. We could reproduce the mass hierarchy and V_<CKM> matrix for quarks precisely. We adopt the see-saw mechanism for explanation of the smallness of neutrino masses and introduce the right-handed Majorana and left-handed Dirac neutrinos. Assuming the democratic mass matrix with small violations for both Majorana and Dirac neutrinos, we can get the hierarchy of charged lepton and effective neutrino masses and the large mixing of neutrinos expressed in V_<NMS>.