Some implications of CP invariance for mixing of Majorana neutrinos

Abstract

Some implications of CP invariance for the mixing of neutrinos with Majorana masses are discussed. It is shown that the phases of the mixing matrix elements are determined both by the CP parities of the Majorana neutrinos and by arbitrary sign factors ξ k in the relevant Majorana conditions. It is also shown that the neutrinoless double β-decay rates depend on the relative CP parities of the massive Majorana neutrinos but do not depend on ξ k . The CP parities have no effect on the neutrino oscillations.