Constraining four neutrino mass patterns from neutrinoless double beta decay

All existing data on neutrino oscillations (including those from the LSND experiment) imply a four neutrino scheme with six different allowed mass patterns. Some of the latter are shown to be disfavored by using a conservative upper bound on the betabeta0upsilon nuclear decay rate, if neutrinos are assumed to be Majorana particles. Comparisons are also made with restrictions from tritium beta-decay and cosmology. (C) 2002 Published by Elsevier Science B.V.