GRAND UNIFICATION OF THE STERILE NEUTRINO

The simplest way to simultaneously understand all existing indications of neutrino oscillations from solar and atmospheric neutrino deficits and the LSND experiment, seems to be to postulate a sterile neutrino. Ws present a. realistic grand unified model based on the gauge group SO(10) X SO(10)' that leads to the desired masses and mixings for the sterile and the known neutrinos needed to understand the above observa tions while fitting those of the known charged fermions. The model is a grand unified realization of the recently proposed idea that the ste rile neutrino is the lightest neutrino of a mirror sector of the unive rse which has identical matter and gauge content as the standard model . The two SO(10)'s operate on the two sectors in a mirror symmetric wa y and are connected by a mixed Higgs representations whose net effect is to connect the superheavy right handed neutrinos of the two sectors . (C) 1998 Elsevier Science B.V. All rights reserved.