Search for Neutrinoless Double Beta Decay with NEMO-3 and Super-NEMO Experiments

University Of Texas At Austin, Austin TX

Investigators

Abstract

The observation of neutrino oscillations has shown that neutrinos have mass. This is the first direct evidence of physics beyond the Standard Model. This discovery has renewed and strengthened interest in neutrinoless double beta decay experiments which provide the only practical way to determine whether neutrinos are Majorana or Dirac particles. Such experiments have also the potential to determine the absolute scale of the neutrino mass and help resolve the neutrino mass hierarchy question. The answers to these fundamental issues may be important to a better understanding of the fundamental forces of Nature and the evolution of the Universe. The authors of this proposal wish to participate in the ongoing experiment NEMO-3, currently the most sensitive search for neutrinoless double beta decays, and in the next generation experiment Super-NEMO. The NEMO team currently operates the NEMO-3 apparatus, located in the Modane Underground Laboratory in the Frejus Tunnel under the French-Italian Alps. In Super-NEMO, just as in NEMO-3, and unlike in most other neutrinoless double beta decay experiments, the final state is reconstructed through several observables relating topology and electron energy. This is a technique common to particle and nuclear physics experiments and provides a powerful tool for measuring and rejecting background. This group has been invited to join the NEMO collaboration to work on both NEMO-3 and Super-NEMO and to bring their expertise with scintillator calorimeters. They are developing a simulation package based on GEANT-4 which is becoming the core optics package for Super-NEMO and an important R&D tool in several labs investigating various calorimeter options for Super-NEMO. They have both validated the results of simulations and constructed prototypes which could provide a valuable input to the final design of Super-NEMO. The broader impact of this proposal stems from the fact that Super-NEMO is essentially an assembly of many small sub-detectors which can be prototyped and operated on a bench. This is ideally suited for training and educating undergraduate students.