K. Whisnant

Majorana neutrino masses from neutrinoless double beta decay and cosmology

Abstract When three Majorana neutrinos describe the solar and atmospheric neutrino data via oscillations, a nonzero measurement of neutrinoless double beta (0 νββ ) decay can determine the sum of neutrino masses ∑ m ν if the solar solution has small-angle mixing, and place a lower bound on ∑ m ν for large-angle solar mixing. If in addition a nonzero ∑ m ν is deduced from cosmology, the neutrino mass spectrum may be uniquely specified for some ranges of neutrino parameters. For ∑ m ν >0.75 eV, the small-angle solar solution is excluded by the current upper limit on neutrinoless double beta decay. In models with maximal solar mixing the CP phases of the neutrinos may be strongly constrained by stringent upper bounds on 0 νββ decay.

Possible indications of neutrino oscillations

Abstract We analyze neutrino oscillations of the ν e , ν μ , ν τ system. Presently available reactor antineutrino data contain indications of oscillations, that have hitherto escaped attention, corresponding to an eigenmass squared difference of δm 2 =1 eV 2 . Two other classes of oscillation solutions are contrasted and further experimental tests are indicated. All the δm 2 must be greater than 10 −3 eV 2 to explain solar and deep mine observations.

General mass bounds for multi-z0 models

Abstract For any electroweak gauge model of the form SU(2) × U(1) × G, where the known fermions do not transform under G, bounds on the lightest and heaviest Z0 masses are derived in terms of the SU(2) and U(1) couplings alone. In principle, there is no absolute upper bound on the lightest Z0 mass.