The SO(10)-inspired leptogenesis timely opportunity

Abstract

Abstract We study the connection between absolute neutrino mass and neutrino mixing parameters within SO(10)-inspired leptogenesis. We show that current favoured values of the unknown neutrino mixing parameters point toward values of the absolute neutrino mass scale that will be fully tested by cosmological observations and neutrinoless double beta decay experiments during next years. In particular, for mD2/mcharm≤ 5, where mD2 is the intermediate Dirac neutrino mass, and for current best fit values of the Dirac phase δ and the atmospheric mixing angle θ23, we derive a lower bound on the neutrinoless double beta decay effective neutrino mass mee ≳ 31 meV and on the sum of the neutrino masses Σimi ≳ 125 meV. These lower bounds hold for normally ordered neutrino masses, as currently favoured by global analyses, and approximately for δ ∈ [155°, 240°] and θ23 in the second octant. If values in this region will be confirmed by future planned long baseline experiments, then a signal at next generation neutrinoless double beta decay experiments is expected, despite neutrino masses being normally ordered. Outside the region, the lower bounds strongly relax but a great fraction of the allowed range of values still allows a measurement of the lightest neutrino mass. Therefore, in the next years low energy neutrino experiments will provide a stringent test of SO(10)-inspired leptogenesis, that might result either in severe constraints or in a strong evidence.