Pseudo Dirac Neutrinos in Seesaw Model

Abstract

Specific class of textures for the Dirac and Majorana mass matrices in the seesaw model leading to a pair of almost degenerate neutrinos is discussed. These textures can be obtained by imposing a horizontal $U(1)$ symmetry. A specific model is discussed in which: (1) All three neutrino masses are similar in magnitude and could lie around eV providing hot component of the dark matter in the universe. (2) Two of these are highly degenerate and their ${(mass)}^2$ difference could solve the solar neutrino problem through large angle MSW solution. (3) The electron neutrino mass may be observable through Kurie plot as well as through search of the neutrinoless double beta decay.

Comments: PRL-Th-94/13 (LATEX File)