The LMA solar solution and fermion universality

Abstract

We suggest that the Large Mixing Angle MSW solar solution, whose unique physical status is confidently supported by the recent results from KamLAND experiments, gets its justification in the fermion universality, interpreted for neutrinos and charged leptons in a straightforward way, most readily in the framework of seesaw mechanism. To this end, we consider an explicit seesaw model, where Dirac and (righthanded) Majorana neutrino masses are simultaneously measurable, and {\it both} are conjectured to be proportional to charged-lepton masses. However, the LMA solar solution is {\it also} not inconsistent with the simple option, where neutrinos are Dirac particles carrying masses proportional to those of charged leptons.