Fluorescent bicolour sensor for low-background neutrinoless double β decay experiments
- PMID: 32572207
- DOI: 10.1038/s41586-020-2431-5
Fluorescent bicolour sensor for low-background neutrinoless double β decay experiments
Abstract
Observation of the neutrinoless double β decay is the only practical way to establish that neutrinos are their own antiparticles1. Because of the small masses of neutrinos, the lifetime of neutrinoless double β decay is expected to be at least ten orders of magnitude greater than the typical lifetimes of natural radioactive chains, which can mimic the experimental signature of neutrinoless double β decay2. The most robust identification of neutrinoless double β decay requires the definition of a signature signal-such as the observation of the daughter atom in the decay-that cannot be generated by radioactive backgrounds, as well as excellent energy resolution. In particular, the neutrinoless double β decay of 136Xe could be established by detecting the daughter atom, 136Ba2+, in its doubly ionized state3-8. Here we demonstrate an important step towards a 'barium-tagging' experiment, which identifies double β decay through the detection of a single Ba2+ ion. We propose a fluorescent bicolour indicator as the core of a sensor that can detect single Ba2+ ions in a high-pressure xenon gas detector. In a sensor made of a monolayer of such indicators, the Ba2+ dication would be captured by one of the molecules and generate a Ba2+-coordinated species with distinct photophysical properties. The presence of such a single Ba2+-coordinated indicator would be revealed by its response to repeated interrogation with a laser system, enabling the development of a sensor able to detect single Ba2+ ions in high-pressure xenon gas detectors for barium-tagging experiments.
References
-
- Majorana, E. Theory of the symmetry of electrons and positrons. Nuovo Cim. 14, 171–184 (1937).
-
- Gómez Cadenas, J. J., Martín-Albo, J., Mezzetto, M., Monrabal, F. & Sorel, M. The search for neutrinoless double beta decay. Riv. Nuovo Cim. 35, 29–98 (2012).
-
- Moe, M. K. New approach to the detection of neutrinoless double beta decay. Phys. Rev. C 44, 931–934 (1991).
-
- Danilov, M. et al. Detection of very small neutrino masses in double beta decay using laser tagging. Phys. Lett. B 480, 12–18 (2000).
-
- nEXO Collaboration. Imaging individual barium atoms in solid xenon for barium tagging in nEXO. Nature 569, 203–207 (2019).
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