Impact and Implication of Bi-Large Neutrino Mixings on GUTs

Abstract

Under the assumptions that 1) the quark/lepton mass matrices take Froggatt-Nielsen's factorized power form λ^{ψ_i+ψ_j} with anomalous U(1) charges ψ_i, and 2) the U(1) charges ψ_i respect the SU(5) GUT structure, we show that the quark mass data necessarily implies the large 2-3 mixing in the MNS mixing matrix U_{MNS}. If we further add the data of the mass squared difference ratio of solar and atmospheric neutrinos, then, it implies that the 1-2 mixing in U_{MNS} is also large, so explaining the bi-large mixing. This analysis also gives a prediction that U_{e3}\equiv(U_{\rm MNS})_{13} should be of order λ\sim (0.1 - 0.5).

arXiv comment8 pages, uses ws-procs9x6.cls, talk at NOON03 (Kanazawa, Feb. 2003)