https://doi.org/10.1140/epjc/s10052-024-13638-0
Regular Article
JUNO sensitivity to invisible decay modes of neutrons
1
Yerevan Physics Institute, Yerevan, Armenia
2
Université Libre de Bruxelles, Brussels, Belgium
3
Universidade Estadual de Londrina, Londrina, Brazil
4
Pontificia Universidade Catolica do Rio de Janeiro, Rio de Janeiro, Brazil
5
Millennium Institute for SubAtomic Physics at the High-energy Frontier (SAPHIR), ANID, Santiago, Chile
6
Pontificia Universidad Católica de Chile, Santiago, Chile
7
Beijing Institute of Spacecraft Environment Engineering, Beijing, China
8
Beijing Normal University, Beijing, China
9
China Institute of Atomic Energy, Beijing, China
10
Institute of High Energy Physics, Beijing, China
11
North China Electric Power University, Beijing, China
12
School of Physics, Peking University, Beijing, China
13
Tsinghua University, Beijing, China
14
University of Chinese Academy of Sciences, Beijing, China
15
Jilin University, Changchun, China
16
College of Electronic Science and Engineering, National University of Defense Technology, Changsha, China
17
Chengdu University of Technology, Chengdu, China
18
Chongqing University, Chongqing, China
19
Dongguan University of Technology, Dongguan, China
20
Jinan University, Guangzhou, China
21
Sun Yat-Sen University, Guangzhou, China
22
Harbin Institute of Technology, Harbin, China
23
University of Science and Technology of China, Hefei, China
24
The Radiochemistry and Nuclear Chemistry Group in University of South China, Hengyang, China
25
Wuyi University, Jiangmen, China
26
Shandong University, Qingdao, Jinan, China
27
Nanjing University, Nanjing, China
28
Guangxi University, Nanning, China
29
East China University of Science and Technology, Shanghai, China
30
School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, China
31
Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai, China
32
Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang, China
33
Nankai University, Tianjin, China
34
Wuhan University, Wuhan, China
35
Xi’an Jiaotong University, Xi’an, China
36
Xiamen University, Xiamen, China
37
School of Physics and Microelectronics, Zhengzhou University, Zhengzhou, China
38
Institute of Physics, National Yang Ming Chiao Tung University, Hsinchu, Taiwan
39
National United University, Miao-li, Taiwan
40
Department of Physics, National Taiwan University, Taipei, Taiwan
41
Faculty of Mathematics and Physics, Charles University, Prague, Czech Republic
42
Department of Physics, University of Jyvaskyla, Jyvaskyla, Finland
43
IJCLab, Université Paris-Saclay, CNRS/IN2P3, Orsay, France
44
Univ. Bordeaux, CNRS, LP2I, UMR 5797, 33170, Gradignan, France
45
IPHC, Université de Strasbourg, CNRS/IN2P3, Strasbourg, France
46
Aix Marseille Univ, CNRS/IN2P3, CPPM, Marseille, France
47
SUBATECH, Université de Nantes, IMT Atlantique, CNRS-IN2P3, Nantes, France
48
III. Physikalisches Institut B, RWTH Aachen University, Aachen, Germany
49
Institute of Experimental Physics, University of Hamburg, Hamburg, Germany
50
Forschungszentrum Jülich GmbH, Nuclear Physics Institute IKP-2, Jülich, Germany
51
Institute of Physics and EC PRISMA+, Johannes Gutenberg Universität Mainz, Mainz, Germany
52
Technische Universität München, München, Germany
53
Helmholtzzentrum für Schwerionenforschung, Planckstrasse 1, 64291, Darmstadt, Germany
54
Eberhard Karls Universität Tübingen, Physikalisches Institut, Tübingen, Germany
55
INFN Catania and Dipartimento di Fisica e Astronomia dell Università di Catania, Catania, Italy
56
Department of Physics and Earth Science, University of Ferrara and INFN Sezione di Ferrara, Ferrara, Italy
57
INFN Sezione di Milano and Dipartimento di Fisica dell Università di Milano, Milan, Italy
58
INFN Milano Bicocca and University of Milano Bicocca, Milan, Italy
59
INFN Milano Bicocca and Politecnico of Milano, Milan, Italy
60
INFN Sezione di Padova, Padua, Italy
61
Dipartimento di Fisica e Astronomia dell’Università di Padova and INFN Sezione di Padova, Padua, Italy
62
INFN Sezione di Perugia and Dipartimento di Chimica, Biologia e Biotecnologie dell’Università di Perugia, Perugia, Italy
63
Laboratori Nazionali di Frascati dell’INFN, Rome, Italy
64
University of Roma Tre and INFN Sezione Roma Tre, Rome, Italy
65
Institute of Electronics and Computer Science, Riga, Latvia
66
Pakistan Institute of Nuclear Science and Technology, Islamabad, Pakistan
67
Joint Institute for Nuclear Research, Dubna, Russia
68
Institute for Nuclear Research of the Russian Academy of Sciences, Moscow, Russia
69
Lomonosov Moscow State University, Moscow, Russia
70
Faculty of Mathematics, Physics and Informatics, Comenius University Bratislava, Bratislava, Slovakia
71
High Energy Physics Research Unit, Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok, Thailand
72
National Astronomical Research Institute of Thailand, Chaing Mai, Thailand
73
Suranaree University of Technology, Nakhon Ratchasima, Thailand
74
University of Warwick, CV4 7AL, Coventry, UK
75
Department of Physics and Astronomy, University of California, Irvine, CA, USA
a
Juno_pub_comm@juno.ihep.ac.cn
b
guowl@ihep.ac.cn
Received:
11
June
2024
Accepted:
20
November
2024
Published online:
4
January
2025
We explore the decay of bound neutrons in the JUNO liquid scintillator detector into invisible particles (e.g., 
or 
), which do not produce an observable signal. The invisible decay includes two decay modes: 
and 
. The invisible decays of s-shell neutrons in 
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 
, 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 
and 
.
© The Author(s) 2024
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