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First ${JSNS}^{2}$ measurement of the electron neutrino flux using the ${}^{12}C (ν_{e}, e^{-}) {}^{12}{N_{g . s .}}$ reaction

T. Dodo^1,2, M. K. Cheoun³, J. H. Choi⁴, J. Y. Choi⁵, J. Goh⁶, K. Haga⁷, M. Harada⁷, S. Hasegawa^2,7, W. Hwang⁶ et al. ( ${JSNS}^{2}$ Collaboration)

W. Hwang⁶, H. I. Jang⁵, J. S. Jang⁸, K. K. Joo⁹, D. E. Jung¹⁰, S. K. Kang¹¹, Y. Kasugai⁷, T. Kawasaki¹², E. M. Kim⁹, E. J. Kim¹³, S. Y. Kim⁹, S. B. Kim¹⁴, H. Kinoshita⁷, T. Konno¹², D. H. Lee^15,*, C. Little¹⁶, T. Maruyama¹⁵, E. Marzec¹⁶, S. Masuda⁷, S. Meigo⁷, D. H. Moon⁹, T. Nakano¹⁷, M. Niiyama¹⁸, K. Nishikawa¹⁵, M. Y. Pac⁴, B. J. Park¹⁹, H. W. Park⁹, J. B. Park³, J. S. Park⁹, J. S. Park¹⁹, R. G. Park⁹, S. J. M. Peeters²⁰, J. W. Ryu¹⁹, K. Sakai⁷, S. Sakamoto⁷, T. Shima¹⁷, C. D. Shin¹⁵, J. Spitz¹⁶, F. Suekane¹, Y. Sugaya¹⁷, K. Suzuya⁷, Y. Yamaguchi⁷, I. S. Yeo⁴, and I. Yu¹⁰ ( ${JSNS}^{2}$ Collaboration)

¹Research Center for Neutrino Science, Tohoku University, 6-3 Azaaoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8578, Japan
²Advanced Science Research Center, JAEA, 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195, Japan
³Department of Physics and OMEG Institute, Soongsil University, 369 Sangdo-ro, Dongjak-gu, Seoul, 06978, Korea
⁴Laboratory for High Energy Physics, Dongshin University, 67, Dongshindae-gil, Naju-si, Jeollanam-do, 58245, Korea
⁵Department of Fire Safety, Seoyeong University, 1 Seogang-ro, Buk-gu, Gwangju, 61268, Korea
⁶Department of Physics, Kyung Hee University, 26, Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Korea
⁷J-PARC Center, JAEA, 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195, Japan
⁸GIST College, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju, 61005, Korea
⁹Department of Physics, Chonnam National University, 77, Yongbong-ro, Buk-gu, Gwangju, 61186, Korea
¹⁰Department of Physics, Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon-si, Gyeonggi-do, 16419, Korea
¹¹School of Liberal Arts, Seoul National University of Science and Technology, 232 Gongneung-ro, Nowon-gu, Seoul, 139-743, Korea
¹²Department of Physics, Kitasato University, 1 Chome-15-1 Kitazato, Minami Ward, Sagamihara, Kanagawa, 252-0329, Japan
¹³Division of Science Education, Jeonbuk National University, 567 Baekje-daero, Deokjin-gu, Jeonju-si, Jeollabuk-do, 54896, Korea
¹⁴School of Physics, Sun Yat-sen (Zhongshan) University, Haizhu District, Guangzhou, 510275, China
¹⁵High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki, 305-0801, Japan
¹⁶University of Michigan, 500 S. State Street, Ann Arbor, Michigan 48109, USA
¹⁷Research Center for Nuclear Physics, Osaka University, 10-1 Mihogaoka, Ibaraki, Osaka, 567-0047, Japan
¹⁸Department of Physics, Kyoto Sangyo University, Motoyama, Kamigamo, Kita-Ku, Kyoto-City, 603-8555, Japan
¹⁹Department of Physics, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu, 41566, Korea
²⁰Department of Physics and Astronomy, University of Sussex, Falmer, Brighton, BN1 9RH, United Kingdom

^*Contact author: leedh@post.kek.jp

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Phys. Rev. D 112, 032012 – Published 28 August, 2025

DOI: https://doi.org/10.1103/fq6x-6d19

Abstract

${JSNS}^{2}$ (J-PARC Sterile Neutrino Search at J-PARC Spallation Neutron Source) is an experiment searching for sterile neutrinos through the observation of ${\bar{ν}}_{μ} \to {\bar{ν}}_{e}$ appearance oscillations, using neutrinos produced by muon decay-at-rest. A key aspect of the experiment involves accurately understanding the neutrino flux and the quantities of pions and muons, which are progenitors of (anti)neutrinos, given that their production rates have yet to be measured. We present the first electron-neutrino flux measurement using ${}^{12}C (ν_{e}, e^{-})^{12} N_{g . s .}$ reaction in ${JSNS}^{2}$ , yielding a flux of $(6.7 \pm 1.6 (stat) \pm 1.7 (syst)) \times 10^{- 9} {cm}^{- 2} {proton}^{- 1}$ at the ${JSNS}^{2}$ detector location, located at 24 meters distance from the mercury target. This flux measurement is consistent with predictions from simulations based on hadron models.

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References (23)

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Phys. Rev. D 112, 032012– Published 28 August, 2025

Vol. 112, Iss. 3 — 1 August 2025

Received 24 December 2024
Accepted 24 July 2025

DOI: https://doi.org/10.1103/fq6x-6d19

Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP³.

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First ${JSNS}^{2}$ measurement of the electron neutrino flux using the ${}^{12}C (ν_{e}, e^{-}) {}^{12}{N_{g . s .}}$ reaction

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First JSNS2 measurement of the electron neutrino flux using the C12(νe,e−)Ng.s.12 reaction

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First ${JSNS}^{2}$ measurement of the electron neutrino flux using the ${}^{12}C (ν_{e}, e^{-}) {}^{12}{N_{g . s .}}$ reaction