The possibility to determine the neutrino masses by KATRIN experiment

We study the discovery potential of future beta decay experiments on searches for the neutrino mass in the sub-eV range, and in particular, the KATRIN experiment with sensitivity m > 0.3 eV. The effects of neutrino mass and mixing on the beta decay spectrum in the neutrino schemes which explain the solar and atmospheric neutrino data (3ν-schemes) are discussed. Also, the effects in the 4ν-schemes which accommodate LSND results as well as the solar and atmospheric neutrino data, are explored