Neutrinoless Double Beta Decay and its "Inverse"
  Recent considerations by these authors pointed out the attractive features which a search for the exchange of heavy Majorana neutrinos could have for solving the mass and the lepton number puzzles for all neutrinos, in TeV-level electron-electron scattering. In the present note, we show that, contrary to subsequently published arguments, non-observation of neutrinoless double beta decay has, to date, no bearing on the promise of this important task for future linear electron colliders. 
Clemens A. Heusch (Santa Cruz Institute for Particle Physics), Peter   Minkowski (Institute for Theoretical Physics, Bern)