NEUTRINO MIXING IN A DEMOCRATIC SEESAW MASS MATRIX MODEL

Abstract

On the basis of a seesaw-type mass matrix model for quarks and leptons, [Formula: see text] where mL∝mR are universal for f=u, d, v and e (up-quark, downquark, neutrino and charged lepton sectors respectively), and MF has a form [(unit matrix)+(democratic-type matrix)], neutrino masses and mixings are investigated. We try to understand a large vµ−vτ mixing, i.e. sin2 2θ23~1, with mv1 ≪ mv2~mv3, which has been suggested by the atmospheric neutrino data.