Explicit seesaw with nearly bimaximal neutrino mixing and no LSND effect

Abstract

An explicit model of neutrino texture is presented, where in the 6 times 6 mass matrix the Majorana lefthanded component is zero, the Majorana righthanded component - diagonal with equal entries, and the Dirac component gets a hierarchical structure, deformed by nearly bimaximal mixing. If the Majorana righthanded component dominates over the Dirac component, the familiar seesaw mechanism leads effectively to the popular, nearly bimaximal oscillations of active neutrinos. The Dirac component, before its deformation, may be similar in shape to the charged-lepton and quark mass matrices. Then, parameters for solar and atmospheric neutrinos may be related to each other, predicting from the SuperKamiokande value of Delta m_{32}^2 a tiny Delta m_{21}^2, typical for MSW LOW solar solution (rather than for MSW Large Mixing Angle solution).