We discuss the physics potential of future tritium beta-decay experiments having a sensitivity to a neutrino mass ~\sqrt{ |\Delta m^{ 2}_{ 23}|}~5x10^{ -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(m_j) << \sqrt{ |\Delta m^{ 2}_{ 23}|}, it would imply that the neutrino mass spectrum is of the inverted hierarchical type.
Categories: hep-ph