Scuola Internazl Super Studi Avanzati, I-34014 Trieste, Italy
; Ist Nazl Fis Nucl, Sez Trieste, I-34014 Trieste, Italy
; CCAST, World Lab, Beijing 100080, Peoples R China
; Chinese Acad Sci, Inst High Energy Phys, Beijing 100039, Peoples R China
We generalize the democratic neutrino mixing ansatz by incorporating the type-II seesaw mechanism with S(3) flavor symmetry. For only the triplet mass term or only the conventional seesaw term large neutrino mixing can be achieved only by assuming an unnatural suppression of the flavor democracy contribution. We show that bilarge neutrino mixing can naturally appear if the flavor democracy term is strongly suppressed due to significant cancellation between the conventional seesaw and triplet mass terms. Explicit S(3) symmetry breaking yields successful neutrino phenomenology and various testable correlations between the neutrino mass and mixing parameters. Among the results are a normal neutrino mass ordering, 0.005 < \U-e3\ < 0.057, 1 - sin(2)2theta(23) greater than or equal to 0.005, positive J(CP) and moderate cancellation in the effective mass of the neutrinoless double beta decay. (C) 2004 Elsevier B.V. All rights reserved.