SISSA 18/2006/EP hep-ph/0603178 A COMMENT ON THE MEASUREMENT OF NEUTRINO MASSES IN β-DECAY EXPERIMENTS

We discuss the physics potential of future tritium β-decay experiments having a sensitivity to a neutrino mass ∼ √ |∆m23| ∼ 5 × 10−2 eV. The case of three-neutrino mixing is analised. A negative result of such an experiment would imply that the neutrino mass spectrum is of normal hierarchical type. The interpretation of a positive result would depend on the value of the lightest neutrino mass; if the lightest neutrino mass satisfies the inequality min(mj) ≪ √ |∆m23|, it would imply that the neutrino mass spectrum is of the inverted hierarchical type.