Universal Texture of Quark and Lepton Mass Matrices with an Extended Flavor $2\leftrightarrow 3$ Symmetry
Against the conventional picture that the mass matrix forms in the quark sectors will take somewhat different structures from those in the lepton sectors, on the basis of an idea that all the mass matrices of quarks and leptons have the same texture, a universal texture of quark and lepton mass matrices is proposed by assuming a discrete symmetry Z_3 and an extended flavor 2\leftrightarrow 3 symmetry. The texture is described by three parameters (including phase parameter). According to this ansatz, the neutrino masses and mixings are investigated.