1. Some Comments to the Neutrinoless Double Beta-Decay
Search Projects
K. Takahashi, KEK
• One of the Most Important and Long Term Experiments
in Particle Physics Research is the one,such as,
Proton Decay Search, and
Neutrinoless Double Beta Decay Search.
• Proton Decay is for a Search for Baryon Number Non-Conservation Research.
• Neutrinoless Double Beta Decay Search is a Search for Lepton Number non-Conservation Research, that also relates to
Majorana-Character of Neutrino.

2. Since observation of Neutrino Oscillation means that neutrinos
have some definitive mass,an observation of Double Beta Decay
without neutrino could tell us some values for neutrino mass.
• Examples of double beta decay nuclei:

4. • Experimental Methods for Detection;
Search for Neutrinoless Double Beta Decay
• Calorimetric Detectors ;
(Ionization, Bolometric, & Scintillation )
• Tracking Detection ;
Important Signals for decay-events ;
Q-values or Energy Release.
Ionization density for particle-identification,
Detection of decaying vertex ,
Identification of decaying tracks ,
Rejection of background events .
• Call for International Collaboration !!