Rare multi-nucleon decays with the full data sets of the Majorana Demonstrator

Summary

The Majorana Demonstrator, an ultra-low-background experiment, searched for rare multi-nucleon decays in 76Ge. The experiment utilized modular high-purity Ge detector arrays and accumulated a full dataset of 64.5 kg yr of enriched active exposure. New half-life limits were set for three-nucleon decay modes, including 1.27×1026 years for 76Ge(ppp) → 73Cu e+π+π+ and 76Ge(ppn) → 73Zn e+π+. The half-life limit for the invisible tri-proton decay mode of 76Ge was found to be 1.4×1025 yr.

Highlights

• The Majorana Demonstrator searched for rare multi-nucleon decays in 76Ge.
• New half-life limits were set for three-nucleon decay modes.
• The experiment utilized modular high-purity Ge detector arrays.
• The dataset consisted of 64.5 kg yr of enriched active exposure.
• The half-life limit for the invisible tri-proton decay mode of 76Ge was found to be 1.4×1025 yr.
• The experiment aimed to investigate neutrinoless double-beta decay (0νββ).
• The results improve previously explored three-nucleon decay modes in Ge isotopes.

Key Insights

• The Majorana Demonstrator's search for rare multi-nucleon decays in 76Ge provides new insights into the stability of protons and neutrons within nuclei. The experiment's findings have significant implications for our understanding of the fundamental forces of nature and the potential for new physics beyond the Standard Model.
• The use of modular high-purity Ge detector arrays in the Majorana Demonstrator allowed for the accumulation of a large dataset, enabling the experiment to set new half-life limits for three-nucleon decay modes. This technological advancement demonstrates the potential for future experiments to probe even more rare and exotic decay modes.
• The investigation of neutrinoless double-beta decay (0νββ) is a key area of research in nuclear physics, as it has the potential to reveal new information about the nature of neutrinos and the fundamental forces of nature. The Majorana Demonstrator's search for 0νββ in 76Ge provides valuable insights into this process and sets the stage for future experiments.
• The observation of rare multi-nucleon decays would have significant implications for our understanding of the universe, as it would provide evidence for the existence of new physics beyond the Standard Model. The Majorana Demonstrator's search for these decays demonstrates the potential for experiments to probe the fundamental laws of physics and reveal new insights into the nature of reality.
• The half-life limits set by the Majorana Demonstrator for three-nucleon decay modes provide a new benchmark for future experiments to aim for. These limits demonstrate the potential for experiments to probe even more rare and exotic decay modes, and highlight the importance of continued research into the fundamental forces of nature.
• The Majorana Demonstrator's use of advanced data analysis techniques, such as pulse-shape discrimination, enabled the experiment to reduce background interference and set new half-life limits for three-nucleon decay modes. This technological advancement demonstrates the potential for future experiments to utilize advanced data analysis techniques to probe even more rare and exotic decay modes.
• The search for rare multi-nucleon decays is an active area of research, with several experiments currently underway or planned. The Majorana Demonstrator's findings demonstrate the potential for these experiments to reveal new insights into the fundamental forces of nature and the stability of protons and neutrons within nuclei.

Mindmap

Citation

Arnquist, I. J., Avignone, F. T., Barabash, A. S., Bhimani, K. H., Blalock, E., Bos, B., Busch, M., Chan, Y.-D., Chapman, J. R., Christofferson, C. D., Chu, P.-H., Cuesta, C., Detwiler, J. A., Efremenko, Yu., Ejiri, H., Elliott, S. R., Fuad, N., Giovanetti, G. K., Green, M. P., … Yu, C.-H. (2024). Rare multi-nucleon decays with the full data sets of the Majorana Demonstrator (Version 1). arXiv. https://doi.org/10.48550/ARXIV.2412.16047