Neutrinoless double beta decay is one of the best probes for physics beyond the standard model of electroweak interactions. Its existence is tied to fundamental aspects of particle physics such as lepton number non-conservation, neutrino mass, right-handed currents in the
electroweak interaction, a massless Goldstone boson (Majoron), the structure of the Higgs sector and supersymmetry. The NEMO-3 experiment is to investigate double beta decay processes with a new low-background tracking detector able to study different isotopes with probe masses up to 10 kg. The first experimental run of ~3 years will be performed with 6.9 kg of 100Mo, 0.93 kg of 28Se, 0.4 kgof 116Cd, 0.45 kg of 130Te, 36.5 g of 150Nd, 9.43 g of 96Zr and 7 g of 48Ca.
Objectives are as follows:
1) To obtain limits (or to detect the process) on neutrinoless double beta decay of the isotopes 100Mo, 82Se, 116Cd, 130Te, 150Nd, 96Zr and 48Ca exceeding current ones approximately 10-100 times. In the case of 100Mo to reach sensitivity to neutrino mass on the level (0.1-0.3) eV.
2) To obtain limits (or to detect the process) on double beta decay with Majoron emission of the isotopes 100Mo, 82Se, 116Cd, 130Te,
150Nd, 96Zr and 48Ca exceeding current ones approximately 10-100 times. In the case of 100Mo, 82Se and 130Te to reach sensitivity to coupling constant of Majoron to neutrino on the level ~10-5. To investigate new Majoron decay modes.
3) To investigate two-neutrino double beta decays of the isotopes 100Mo, 82Se, 116Cd, 130Te, 150Nd, 96Zr and 48Ca with accuracy higher than current ones (half-lives, energy and angular distributions, single electron distribution).
4) To detect and investigate two neutrino double beta decay of 100Mo to the first 0+ excited state. To obtain first time energy and angular distributions for this type of decay.
5) To continue theoretical investigations of double beta decay problem with the aim to improve the quality of nuclear matrix element calculations and, as a result, to produce more correct limits(or values!) on neutrino mass, right handed current parameters, Majoron-Majorana neutrino coupling constant etc.
6) To investigate precisely (theoretically and experimentally) the
Shapes of two-neutrino double beta decay in 100Mo and 116Cd to confirm (or to reject) the Single State Dominance Hypothesis.