Radiative magnification of neutrino mixings and a natural explanation of the neutrino anomalies

We show that the neutrino mixing pattern with the large mixing required for the atmospheric neutrino problem and the small mixing angle MSW solution f or the solar neutrino problem can be naturally generated through radiative magnification, even though all the mixing angles at the seesaw scale may be small, This can account for the neutrino anomalies as well as the CHOOZ co nstraints in the context of quark-lepton unified theories, where the quark and lepton mixing angles are expected to be similar in magnitude at the hig h scale, We also indicate the 4v mixing scenarios for which this mechanism of radiative magnification can provide a natural explanation, (C) 2000 Else vier Science B.V. All rights reserved.