Possibility of detecting neutrinoless double beta decays using nuclear emulsions

Abstract

A complementary physics to the LHC subjects comes from the neutrino sector which has already opened a window beyond the standard model. Neutrino oscillations have already proved that neutrinos have non zero masses. But, neutrino nature and absolute mass scale are still major questions which answers could have big effects at the cosmological level. Several neutrinoless double beta decay experiments are underway or planed for the near future trying to address the above questions. These experiments mainly use bolometric techniques or gaseous counters coupled with scintillator detectors. Energy resolution is significantly better in bolometric experiments but experiments coupling tracking with calorimetry have much better background rejection by identifying the two electrons produced by the double beta decay process. Another technique of detecting the electrons with reasonable energy resolution without using electronic detectors is the utilisation of nuclear emulsions. This technique has the advantage of precise tracking and vertexing even for low energy electrons, allowing a high background rejection. This possibility is presented in this paper.