A1 Journal article (refereed)
JUNO sensitivity to invisible decay modes of neutrons (2025)

JUNO Collaboration. (2025). JUNO sensitivity to invisible decay modes of neutrons. European Physical Journal C, 85, Article 5. https://doi.org/10.1140/epjc/s10052-024-13638-0

JYU authors or editors

Publication details

All authors or editors: JUNO Collaboration

Journal or series: European Physical Journal C

ISSN: 1434-6044

eISSN: 1434-6052

Publication year: 2025

Publication date: 04/01/2025

Volume: 85

Article number: 5

Publisher: Springer Nature

Publication country: Germany

Publication language: English

DOI: https://doi.org/10.1140/epjc/s10052-024-13638-0

Publication open access: Openly available

Publication channel open access: Open Access channel

Web address of parallel published publication (pre-print):  https://doi.org/10.48550/arXiv.2405.17792

Abstract

We explore the bound neutrons decay into invisible particles (e.g., n→3ν or nn→2ν) in the JUNO liquid scintillator detector. The invisible decay includes two decay modes: n→inv and nn→inv. The invisible decays of s-shell neutrons in 12C will leave a highly excited residual nucleus. Subsequently, some de-excitation modes of the excited residual nuclei can produce a time- and space-correlated triple coincidence signal in the JUNO detector. Based on a full Monte Carlo simulation informed with the latest available data, we estimate all backgrounds, including inverse beta decay events of the reactor antineutrino ν¯e, natural radioactivity, cosmogenic isotopes and neutral current interactions of atmospheric neutrinos. Pulse shape discrimination and multivariate analysis techniques are employed to further suppress backgrounds. With two years of exposure, JUNO is expected to give an order of magnitude improvement compared to the current best limits. After 10 years of data taking, the JUNO expected sensitivities at a 90% confidence level are τ/B(n→inv)>5.0×1031yr and τ/B(nn→inv)>1.4×1032yr.

Keywords: particle physics; particle accelerators; nuclear physics; neutrons

Contributing organizations

Ministry reporting: Yes

VIRTA submission year: 2025

Preliminary JUFO rating: 2