Generation Structure and Proton Decay Problem

Possible generation structure is investigated. We considere alternativepossibility of combination of leptons and quarks to compose each generation,where the combination of $(\nu_{\tau},{\tau})$ and $(u,d)$ compose ageneration. Our model exhibits the hierarcy structure after sea-saw mechanismprovived that possible existence of realistic right-handed neutrinos are takeninto account. Then, in the GUTs model based on our scheme, possibleinter-generation properties are examined together with the classification ofgauge bosons. It is shown that if our scheme is realized, the proton decayexhibits different mode from ordinary one.Comment: 9 page