Seesaw neutrino masses and mixing with extended democracy

Abstract

In the context of a minimal extension of the Standard Model with three extra heavy right-handed neutrinos, we propose a model for neutrino masses and mixing based on the hipothesis of a complete alignment of the lepton mass matrices in flavour space. Considering a uniform quasi-democratic structure for these matrices, we show that, in the presence of a highly hierarchical right-handed neutrino mass spectrum, the effective neutrino mass matrix, obtained through the seesaw mechanism, can reproduce all the solutions of the solar neutrino problem.

Comments: Latex, 3pages. Uses espcrc2.sty. Talk given at the Europhysics Neutrino Oscillation Workshop - NOW 2000. To appear in Nucl. Phys. B, Proceedings Supplements