On Teraelectronvolt Majorana Neutrinos

The issue of existence of Majorana neutrinos with masses of the order of TeV and substantial couplings is addressed. A general neutrino mass matrix Mν with both features is constructed, however, the form of Mν is constrained very much by severe relations among the elements of mD and MR sub-matrices of Mν. These general relations follow from the perturbative construction of the light neutrino mass spectrum. To avoid such large correlations between low mass parameters in mD and large mass parameters in MR , the Jezabek-Sumino see-saw model of bi-maximal neutrino mixing adopted to the TeV scale and the issue of possible symmetries of the matrix Mν are discussed. Results are supported by a few numerical examples which show directly the complexity of the problem. (author)