Neutron-Multiplicity Measurement in Muon Capture on Oxygen Nuclei in the Gadolinium-Loaded Super-Kamiokande Detector

Physical Review Letters 2026 Open access

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Authors: S. Miki, K. Abe, S. Abe, Y Asaoka, C. Bronner, M. Harada, Y Hayato, K. Hiraide, K Hosokawa, K. Ieki, M. Ikeda, J Kameda
+88 more Y. Kanemura, R. Kaneshima, Y. Kashiwagi, Y. Kataoka, S. Mine, M. Miura, S Moriyama, M. Nakahata, S Nakayama, Y Noguchi, K. Okamoto, G. Pronost, K. Sato, H Sekiya, H. Shiba, K Shimizu, M. Shiozawa, Y. Sonoda, Y. Suzuki, A. Takeda, Y. Takemoto, A. Takenaka, H. Tanaka, S. Watanabe, T Yano, T. Kajita, K Okumura, T Tashiro, T. Tomiya, X. Wang, S. Yoshida, G. D. Megias, P. Fernandez, L. Labarga, N. Ospina, B. Zaldivar, B. W. Pointon, C. Yanagisawa, E. Kearns, J. L. Raaf, L. Wan, T. Wester, J. Bian, B. Cortez, N. J. Griskevich, S. Locke, M. B. Smy, H. W. Sobel, V. Takhistov, A. Yankelevich, J. Hill, M. C. Jang, S. H. Lee, D. H. Moon, R. G. Park, B. S. Yang, B. Bodur, K. Scholberg, C. W. Walter, A Beauchene, O. Drapier, A. Ershova, A. Giampaolo, Th. A. Mueller, A. D. Santos, P. Paganini, C. Quach, B. Quilain, R. Rogly, T. Nakamura, J. S. Jang, R. P. Litchfield, L. N. Machado, F. J. P. Soler, J. G. Learned, K. Choi, N. Iovine, S. Cao, L. H. V. Anthony, D. Martin, N. W. Prouse, M. Scott, A. A. Sztuc, Y. Uchida, V. Berardi, N. F. Calabria, M. G. Catanesi, E. Radicioni
DOI: 10.1103/pmyx-jn3s
Cited by: 0
References: 25

Abstract

In recent neutrino detectors, neutrons produced in neutrino reactions play an important role. Muon capture on oxygen nuclei is one of the processes that produce neutrons in water Cherenkov detectors. We measured neutron multiplicity in the process using cosmic ray muons that stop in the gadolinium-loaded Super-Kamiokande detector. For this measurement, neutron detection efficiency is obtained with the muon capture events followed by gamma rays to be 50.2_{-2.1}^{+2.0}%. By fitting the observed multiplicity considering the detection efficiency, we measure neutron multiplicity in muon capture as P(0)=24±3%, P(1)=70_{-2}^{+3}%, P(2)=6.1±0.5%, P(3)=0.38±0.09%. This is the first measurement of the multiplicity of neutrons associated with muon capture on oxygen without neutron energy threshold.

Fields of Study & Subjects

Neutrino Physics Research Dark Matter and Cosmic Phenomena Radiation Detection and Scintillator Technologies

Publication details

Journal / source
Physical Review Letters
Publisher
American Physical Society (APS)
Volume
136
Issue
13
Pages
131801–131801
Publication date
29 January 2026
Language
EN