Detection of very small neutrino masses in double-beta decay using laser tagging

We describe an approach to the study of neutrino masses that combines quantum optics techniques with radiation detectors to obtain unprecedented sensitivity. With it the search for Majorana neutrino masses down to similar to 10 meV will become accessible. The experimental technique uses the possibility of individually detecting Ba+-ions in the final state of Xe-136 double-beta decay via resonant excitation with a set of lasers aimed at a specific location in a large Time Projection Chamber. The specificity of the atomic levels provides tagging and, together with more traditional event recognition parameters, greatly suppresses radioactive backgrounds. (C) 2000 Published by Elsevier Science B.V. All rights reserved.