Constraints on Neutrino Mass Matrix with no Majorana Phases

Abstract

In the basis where charged lepton mass matrix is real and diagonal, we havefound conditions under which there are no Majorana phases in neutrino massmatrix. An important feature of the condition is that it has been formulatedin terms of modulus of the elements of neutrino mass matrix independent ofphases. If these conditions are satisfied, a CKM type matrix is enough tomake neutrino Majorana mass matrix real and diagonal without any need ofMajorana phases. As an application, we explore the possibility of Majoranaphases in all phenomenologically acceptable neutrino mass matrices with twotexture zeros.