Year: 2026
Type: preprint
Abstract: We report an indication of $\barν_e$ from the diffuse supernova neutrino background (DSNB) based on a spectral fit analysis of a 5003.0-day dataset in Super-Kamiokande. Key improvements over previous searches include enhanced rejection of atmospheric $ν$ backgrounds, updated evaluations of systematic uncertainties, and a refined spectral fitting method. Using a representative DSNB model, the best-fit flux was determined to be $3.6^{+1.6}_{-1.5}~\mathrm{cm^{-2}\,s^{-1}}$ for $E_ν>13.3$~MeV, corresponding to a $2.6σ$ tension with a null hypothesis ($99.5\%$ C.L., one-sided). Similar significances were obtained with signal models of varying spectral shapes.
Source: arXiv (Cornell University)
Authors: Kamiokande Collaboration, Abe, K., Asaoka, Y., Harada, M., Hayato, Y., Hiraide, K., Hung, T. H., Ieki, K., Ikeda, M., Kameda, J., Kataoka, Y., Mine, S., Miura, M., Moriyama, S., Nakagiri, K., Nakahata, M., Nakayama, S., Noguchi, Y., Pronost, G., Sato, K., Sekiya, H., Shinoda, R., Shiozawa, M., Suzuki, Y., Takeda, A., Takemoto, Y., Tanaka, H., Chen, S., Itow, Y., Kajita, T., Nishijima, R., Okumura, K., Tashiro, T., Tomiya, T., Wang, X., Arcones, F. J. de Garay, Fernandez, P., Labarga, L., Samudio, D., Yanagisawa, C., Jargowsky, B., Kearns, E., Mirabito, J., Wan, L., Wester, T., Pointon, B. W., Bian, J., Cortez, B., Griskevich, N. J., Jiang, Y., Smy, M. B., Sobel, H. W., Takhistov, V., Hill, J., Xu, B. D., Jung, D., Moon, D. H., Park, R. G., Yang, B. S., Scholberg, K., Walter, C. W., Chahlaoui, A., Drapier, O., Ershova, A., Ferey, M., Hu, Z., Blévec, E. Le, Leplumey, T., Mueller, Th. A., Paganini, P., Quach, C., Rogly, R., Nakamura, T., Jang, J. S., Litchfield, R. P., Machado, L. N., Soler, F. J. P., Learned, J. G., Choi, K., Cao, S., Ngoc, T. V., Anthony, L. H. V., Prouse, N. W., Scott, M., Uchida, Y., Berardi, V., Calabria, N. F., Catanesi, M. G., Ospina, N., Radicioni, E., Langella, A., De Rosa, G., Burton, G. T., Collazuol, G., Feltre, M., Mattiazzi, M., Ludovici, L., Gonin, M., Périssé, L., Quilain, B., Fukazawa, M., Horiuchi, S., Kawabata, A., Liu, Y. M., Maekawa, Y., Nishimura, Y., Oka, A., Utagawa, Z., Akutsu, R., Friend, M., Hasegawa, T., Hino, Y., Ishida, T., Kobayashi, T., Matsubara, T., Nakadaira, T., Oyama, Y., Yrey, A. Portocarrero, Sakashita, K., Sekiguchi, T., Tanigawa, H., Bhuiyan, N., Di Lodovico, F., Katori, T., Kralik, R., Latham, N., Ramsden, R. M., Siccardi, V., Aoyama, S., Bambara, H., Inaba, Y., Ito, H., Nishigami, M., Sone, T., Suzuki, A. T., Takeuchi, Y., Wada, S., Zhong, H., Feng, J., Feng, L., Fujimoto, N., Han, S., Hikida, J., Kawaue, M., Kikawa, T., Nakanishi, F., Nakaya, T., Wendell, R. A., Jenkins, S. J., Limbu, U., McCauley, N., Fanì, M., Wilking, M. J., Xie, Z., Fukuda, Y., Menjo, H., Yoshioka, Y., Lagoda, J., Zalipska, J., Yano, T., Mori, M., Jiang, J., Asano, Y., Hamaguchi, K., Ishino, H., Koshio, Y., Ohshita, S., Tada, T., Ishizuka, T., Barr, G., Barrow, D., Wark, D., Holin, A., Nova, F., Jo, M., Jung, S., Yoo, J., Kneale, L., Peacock, T., Stowell, P., Okazawa, H., Lakshmi, S. M., Hong, S., Kwon, E., Lee, M. W., Seo, J. W., Yu, I., Ashida, Y., Ichikawa, A. K., Kobayashi, S., Nakamura, K. D., Abe, S., Cai, W., Endo, Y., Goto, S., Hayasaki, H., Kodama, S., Kong, Y., Li, K., Masaki, Y., Mizuno, Y., Muro, T., Nakajima, Y., Sekiyama, M., Taniuchi, N., Yamazumi, T., Yokoyama, M., de Perio, P., Fujita, S., Jesús-Valls, C., Martens, K., Marti, Ll., Santos, A. D., Tsui, K. M., Vagins, M. R., Izumiyama, S., Kuze, M., Matsumoto, R., Ise, C., Ishitsuka, M., Sugo, M., Wako, M., Yamauchi, K., Nakano, Y., Yankelevich, A., Cormier, F., Gaur, R., Hartz, M., Konaka, A., Li, X., Smithers, B. R., Chen, S., Wu, Y., Zhang, A. Q., Zhang, B., Adhikary, H., Girgus, M., Govindaraj, P., Posiadala-Zezula, M., Prabhu, Y. S., Boyd, S. B., Edwards, R., Hadley, D., O'Flaherty, M., Richards, B., Ali, A., Jamieson, B., Bronner, C., Horiguchi, D., Minamino, A., Sasaki, Y.
Institutions: Institute for Cosmic Ray Research, Kamioka Observatory, The University of Tokyo, University of California, Irvine, Centre National de la Recherche Scientifique, International Laboratory for Astrophysics, Neutrino and Cosmology Experiments, Universidad Autónoma de Madrid, Borough of Manhattan Community College, City University of New York, Boston University, British Columbia Institute of Technology, High Energy Accelerator Research Organization, California State University, Dominguez Hills, University of Chinese Academy of Sciences, Chonnam National University, Duke University, École Polytechnique, Institut National de Physique Nucléaire et de Physique des Particules, Laboratoire Leprince-Ringuet, Gifu University, Gwangju Institute of Science and Technology, University of Glasgow, University of Hawaiʻi at Mānoa, University of Hawaii System, Institute for Basic Science, International Centre for Interdisciplinary Science and Education, Imperial College London, Istituto Nazionale di Fisica Nucleare, Sezione di Bari, Polytechnic University of Bari, Istituto Nazionale di Fisica Nucleare, Sezione di Napoli, University of Padua, Istituto Nazionale di Fisica Nucleare, Sezione di Padova, Istituto Nazionale di Fisica Nucleare, Sezione di Roma I, Keio University, King's College London, Kobe University, Kyoto University, University of Liverpool, University of Minnesota, Miyagi University of Education, Institute for Space-Earth Environmental Research, Nagoya University, Kobayashi-Maskawa Institute for the Origin of Particles and the Universe, Nagoya University, National Centre for Nuclear Research, National Institute of Technology, Niihama College, National Institute of Technology, Numazu College, State University of New York, Stony Brook University, Okayama University, Osaka Electro-Communication University, University of Oxford, Rutherford Appleton Laboratory, Science and Technology Facilities Council, Daresbury Laboratory, Seoul National University, University of Sheffield, Shizuoka University of Welfare, University of Silesia in Katowice, Sungkyunkwan University, Tohoku University, Tokyo University of Science, Kavli Institute for the Physics and Mathematics of the Universe, Yokohama National University, University of Warwick, University of Toyama, Institute of Science Tokyo, University of Warsaw, Tsinghua University, Sapienza University of Rome
Language: English
Topic: Neutrino Physics Research
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, U.S. Department of Energy, European Commission, Ministry of Education, Culture, Sports, Science and Technology, National Natural Science Foundation of China, National Research Foundation of Korea, Institute for Basic Science, Horizon 2020 Framework Programme, HORIZON EUROPE Framework Programme, Natural Sciences and Engineering Research Council of Canada, Science and Technology Facilities Council, Japan Society for the Promotion of Science, Nuclear Physics, NextGenerationEU
Awards: G1626428022, G1820956982, G187717830, First Observation of Diffuse Supernova Neutrino Background with Improved Background Modeling, G2814198339, G2818282093, G2907963052, G3049196905, G3297240425, G3345895242, スーパーカミオカンデにおける世界初の超新星背景ニュートリノ観測への挑戦, G3477743816, G3634461281, G3831296399, G3837556332, G4313378819, G4352636101, G4919363105, G507055683, G5093298782, From Super-Kamiokande to Hyper-Kamiokande, G5719138819, G5925907655, G6810656081, G753483755, Understanding the spallation background for Diffuse Supernova Neutrino Background, G7865097842, G8367957132, G8611458396, G9001173469, G9001175882
OpenAlex ID: W7223914300