Author: "Park, R. G." - Searchworks@Jio Institute Digital Library Search Results

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411 results on '"Park, R. G."'

1. Search for proton decay via $p\rightarrow{e^+\eta}$ and $p\rightarrow{\mu^+\eta}$ with a 0.37 Mton-year exposure of Super-Kamiokande

Author: Collaboration, Super-Kamiokande, Taniuchi, N., Abe, K., Abe, S., Asaoka, Y., Bronner, C., Harada, M., Hayato, Y., Hiraide, K., Hosokawa, K., Ieki, K., Ikeda, M., Kameda, J., Kanemura, Y., Kaneshima, R., Kashiwagi, Y., Kataoka, Y., Miki, S., Mine, S., Miura, M., Moriyama, S., Nakahata, M., Nakayama, S., Noguchi, Y., Pronost, G., Okamoto, K., Sato, K., Sekiya, H., Shiba, H., Shimizu, K., Shiozawa, M., Sonoda, Y., Suzuki, Y., Takeda, A., Takemoto, Y., Takenaka, A., Tanaka, H., Watanabe, S., Yano, T., Kajita, T., Okumura, K., Tashiro, T., Tomiya, T., Wang, X., Yoshida, S., Megias, G. D., Fernandez, P., Labarga, L., Ospina, N., Zaldivar, B., Pointon, B. W., Kearns, E., Mirabito, J., Raaf, J. L., Wan, L., Wester, T., Bian, J., Griskevich, N. J., Kropp, W. R., Locke, S., Smy, M. B., Sobel, H. W., Takhistov, V., Yankelevich, A., Hill, J., Jang, M. C., Kim, J. Y., Lee, S. H., Lim, I. T., Moon, D. H., Park, R. G., Yang, B. S., Bodur, B., Scholberg, K., Walter, C. W., Beauchêne, A., Bernard, L., Coffani, A., Drapier, O., Hedri, S. El, Giampaolo, A., Mueller, Th. A., Santos, A. D., Paganini, P., Rogly, R., Nakamura, T., Jang, J. S., Machado, L. N., Learned, J. G., Choi, K., Iovine, N., Cao, S., Anthony, L. H. V., Martin, D., Prouse, N. W., Scott, M., Sztuc, A. A., Uchida, Y., Berardi, V., Calabria, N. F., Catanesi, M. G., Radicioni, E., Langella, A., De Rosa, G., Collazuol, G., Feltre, M., Iacob, F., Lamoureux, M., Mattiazzi, M., Ludovici, L., Gonin, M., Périssé, L., Quilain, B., Fujisawa, C., Horiuchi, S., Kobayashi, M., Liu, Y. M., Maekawa, Y., Nishimura, Y., Okazaki, R., Akutsu, R., Friend, M., Hasegawa, T., Ishida, T., Kobayashi, T., Jakkapu, M., Matsubara, T., Nakadaira, T., Nakamura, K., Oyama, Y., Yrey, A. Portocarrero, Sakashita, K., Sekiguchi, T., Tsukamoto, T., Bhuiyan, N., Boschi, T., Burton, G. T., Di Lodovico, F., Gao, J., Goldsack, A., Katori, T., Migenda, J., Ramsden, R. M., Taani, M., Xie, Z., Zsoldos, S., Kotsar, Y., Ozaki, H., Suzuki, A. T., Takagi, Y., Takeuchi, Y., Yamamoto, S., Zhong, H., Feng, J., Feng, L., Han, S., Hu, J. R., Hu, Z., Kawaue, M., Kikawa, T., Mori, M., Nakaya, T., Wendell, R. A., Yasutome, K., Jenkins, S. J., McCauley, N., Mehta, P., Tarrant, A., Wilking, M. J., Fukuda, Y., Itow, Y., Menjo, H., Ninomiya, K., Yoshioka, Y., Lagoda, J., Mandal, M., Mijakowski, P., Prabhu, Y. S., Zalipska, J., Jia, M., Jiang, J., Jung, C. K., Shi, W., Yanagisawa, C., Hino, Y., Ishino, H., Ito, S., Kitagawa, H., Koshio, Y., Ma, W., Nakanishi, F., Sakai, S., Tada, T., Tano, T., Ishizuka, T., Barr, G., Barrow, D., Cook, L., Samani, S., Wark, D., Holin, A., Nova, F., Jung, S., Yang, J. Y., Yoo, J., Fannon, J. E. P., Kneale, L., Malek, M., McElwee, J. M., Stone, O., Stowell, P., Thiesse, M. D., Thompson, L. F., Wilson, S. T., Okazawa, H., Lakshmi, S. M., Kim, S. B., Kwon, E., Lee, M. W., Seo, J. W., Yu, I., Ichikawa, A. K., Nakamura, K. D., Tairafune, S., Nishijima, K., Koshiba, M., Eguchi, A., Goto, S., Iwamoto, K., Mizuno, Y., Muro, T., Nakagiri, K., Nakajima, Y., Shima, S., Watanabe, E., Yokoyama, M., de Perio, P., Fujita, S., Jesús-Valls, C., Martens, K., Marti, Ll., Tsui, K. M., Vagins, M. R., Xia, J., Izumiyama, S., Kuze, M., Matsumoto, R., Terada, K., Asaka, R., Inomoto, M., Ishitsuka, M., Ito, H., Kinoshita, T., Ommura, Y., Shigeta, N., Shinoki, M., Suganuma, T., Yamauchi, K., Yoshida, T., Nakano, Y., Martin, J. F., Tanaka, H. A., Towstego, T., Gaur, R., Gousy-Leblanc, V., Hartz, M., Konaka, A., Li, X., Chen, S., Wu, Y., Xu, B. D., Zhang, A. Q., Zhang, B., Posiadala-Zezula, M., Boyd, S. B., Edwards, R., Hadley, D., Nicholson, M., O'Flaherty, M., Richards, B., Ali, A., Jamieson, B., Amanai, S., Minamino, A., Pintaudi, G., Sano, S., Sasaki, R., Shibayama, R., Shimamura, R., Suzuki, S., and Wada, K.
Subjects: High Energy Physics - Experiment
Abstract: A search for proton decay into $e^+/\mu^+$ and a $\eta$ meson has been performed using data from a 0.373 Mton$\cdot$year exposure (6050.3 live days) of Super-Kamiokande. Compared to previous searches this work introduces an improved model of the intranuclear $\eta$ interaction cross section, resulting in a factor of two reduction in uncertainties from this source and $\sim$10\% increase in signal efficiency. No significant data excess was found above the expected number of atmospheric neutrino background events resulting in no indication of proton decay into either mode. Lower limits on the proton partial lifetime of $1.4\times\mathrm{10^{34}~years}$ for $p\rightarrow e^+\eta$ and $7.3\times\mathrm{10^{33}~years}$ for $p\rightarrow \mu^+\eta$ at the 90$\%$ C.L. were set. These limits are around 1.5 times longer than our previous study and are the most stringent to date.
Published: 2024

2. First Measurement of Missing Energy Due to Nuclear Effects in Monoenergetic Neutrino Charged Current Interactions

Author: Marzec, E., Ajimura, S., Antonakis, A., Botran, M., Cheoun, M. K., Choi, J. H., Choi, J. W., Choi, J. Y., Dodo, T., Furuta, H., Goh, J. H., Haga, K., Harada, M., Hasegawa, S., Hino, Y., Hiraiwa, T., Hwang, W., Iida, T., Iwai, E., Iwata, S., Jang, H. I., Jang, J. S., Jang, M. C., Jeon, H. K., Jeon, S. H., Joo, K. K., Jung, D. E., Kang, S. K., Kasugai, Y., Kawasaki, T., Kim, E. J., Kim, J. Y., Kim, E. M., Kim, S. Y., Kim, W., Kim, S. B., Kinoshita, H., Konno, T., Kuwata, K., Lee, D. H., Lee, S., Lim, I. T., Little, C., Maruyama, T., Masuda, S., Meigo, S., Monjushiro, S., Moon, D. H., Nakano, T., Niiyama, M., Nishikawa, K., Noumachi, M., Pac, M. Y., Park, B. J., Park, H. W., Park, J. B., Park, J. S., Park, R. G., Peeters, S. J. M., Roellinghoff, G., Rott, C., Ryu, J. W., Sakai, K., Sakamoto, S., Shima, T., Shin, C. D., Spitz, J., Stancu, I., Suekane, F., Sugaya, Y., Suzuya, K., Taira, M., Takeuchi, Y., Wang, W., Waterfield, J., Wei, W., White, R., Yamaguchi, Y., Yeh, M., Yeo, I. S., Yoo, C., Yu, I., and Zohaib, A.
Subjects: High Energy Physics - Experiment
Abstract: We present the first measurement of the missing energy due to nuclear effects in monoenergetic, muon neutrino charged-current interactions on carbon, originating from $K^+ \rightarrow \mu^+ \nu_\mu$ decay-at-rest ($E_{\nu_\mu}=235.5$ MeV), performed with the JSNS$^2$ liquid scintillator based experiment. Towards characterizing the neutrino interaction, ostensibly $\nu_\mu n \rightarrow \mu^- p$ or $\nu_\mu$$^{12}\mathrm{C}$ $\rightarrow \mu^-$$^{12}\mathrm{N}$, and in analogy to similar electron scattering based measurements, we define the missing energy as the energy transferred to the nucleus ($\omega$) minus the kinetic energy of the outgoing proton(s), $E_{m} \equiv \omega-\sum T_p$, and relate this to visible energy in the detector, $E_{m}=E_{\nu_\mu}~(235.5~\mathrm{MeV})-m_\mu~(105.7~\mathrm{MeV}) - E_{vis}$. The missing energy, which is naively expected to be zero in the absence of nuclear effects (e.g. nucleon separation energy, Fermi momenta, and final-state interactions), is uniquely sensitive to many aspects of the interaction, and has previously been inaccessible with neutrinos. The shape-only, differential cross section measurement reported, based on a $(77\pm3)$% pure double-coincidence KDAR signal (621 total events), provides an important benchmark for models and event generators at 100s-of-MeV neutrino energies, characterized by the difficult-to-model transition region between neutrino-nucleus and neutrino-nucleon scattering, and relevant for applications in nuclear physics, neutrino oscillation measurements, and Type-II supernova studies.
Published: 2024

3. First joint oscillation analysis of Super-Kamiokande atmospheric and T2K accelerator neutrino data

Author: Super-Kamiokande, collaborations, T2K, Abe, S., Abe, K., Akhlaq, N., Akutsu, R., Alarakia-Charles, H., Ali, A., Hakim, Y. I. Alj, Monsalve, S. Alonso, Amanai, S., Andreopoulos, C., Anthony, L. H. V., Antonova, M., Aoki, S., Apte, K. A., Arai, T., Arihara, T., Arimoto, S., Asada, Y., Asaka, R., Ashida, Y., Atkin, E. T., Babu, N., Barbi, M., Barker, G. J., Barr, G., Barrow, D., Bates, P., Batkiewicz-Kwasniak, M., Beauchêne, A., Berardi, V., Berns, L., Bhadra, S., Bhuiyan, N., Bian, J., Blanchet, A., Blondel, A., Bodur, B., Bolognesi, S., Bordoni, S., Boyd, S. B., Bravar, A., Bronner, C., Bubak, A., Avanzini, M. Buizza, Burton, G. T., Caballero, J. A., Calabria, N. F., Cao, S., Carabadjac, D., Carter, A. J., Cartwright, S. L., Casado, M. P., Catanesi, M. G., Cervera, A., Chakrani, J., Chalumeau, A., Chen, S., Cherdack, D., Choi, K., Chong, P. S., Chvirova, A., Cicerchia, M., Coleman, J., Collazuol, G., Cook, L., Cormier, F., Cudd, A., Dalmazzone, C., Daret, T., Dasgupta, P., Davis, C., Davydov, Yu. I., De Roeck, A., De Rosa, G., Dealtry, T., Delogu, C. C., Densham, C., Dergacheva, A., Dharmapal, R., Di Lodovico, F., Lopez, G. Diaz, Dolan, S., Douqa, D., Doyle, T. A., Drapier, O., Duffy, K. E., Dumarchez, J., Dunne, P., Dygnarowicz, K., D'ago, D., Edwards, R., Eguchi, A., Elias, J., Emery-Schrenk, S., Erofeev, G., Ershova, A., Eurin, G., Fannon, J. E. P., Fedorova, D., Fedotov, S., Feltre, M., Feng, J., Feng, L., Ferlewicz, D., Fernandez, P., Finch, A. J., Aguirre, G. A. Fiorentini, Fiorillo, G., Fitton, M. D., Patiño, J. M. Franco, Friend, M., Fujii, Y., Fujisawa, C., Fujita, S., Fukuda, Y., Furui, Y., Gao, J., Gaur, R., Giampaolo, A., Giannessi, L., Giganti, C., Glagolev, V., Goldsack, A., Gonin, M., Rosa, J. González, Goodman, E. A. G., Gorin, A., Gorshanov, K., Gousy-Leblanc, V., Grassi, M., Griskevich, N. J., Guigue, M., Hadley, D., Haigh, J. T., Han, S., Harada, M., Harris, D. A., Hartz, M., Hasegawa, T., Hassani, S., Hastings, N. C., Hayato, Y., Heitkamp, I., Henaff, D., Hill, J., Hino, Y., Hiraide, K., Hogan, M., Holeczek, J., Holin, A., Holvey, T., Van, N. T. Hong, Honjo, T., Horiuchi, S., Hosokawa, K., Hu, Z., Hu, J., Iacob, F., Ichikawa, A. K., Ieki, K., Ikeda, M., Iovine, N., Ishida, T., Ishino, H., Ishitsuka, M., Ishizuka, T., Ito, H., Itow, Y., Izmaylov, A., Izumiyama, S., Jakkapu, M., Jamieson, B., Jang, M. C., Jang, J. S., Jenkins, S. J., Jesús-Valls, C., Ji, J. Y., Jia, M., Jiang, J., Jonsson, P., Joshi, S., Jung, C. K., Jung, S., Kabirnezhad, M., Kaboth, A. C., Kajita, T., Kakuno, H., Kameda, J., Kanemura, Y., Kaneshima, R., Karpova, S., Kasetti, S. P., Kashiwagi, Y., Kasturi, V. S., Kataoka, Y., Katori, T., Kawamura, Y., Kawaue, M., Kearns, E., Khabibullin, M., Khotjantsev, A., Kikawa, T., Kim, S. B., King, S., Kiseeva, V., Kisiel, J., Kneale, L., Kobayashi, H., Kobayashi, T., Kobayashi, M., Koch, L., Kodama, S., Kolupanova, M., Konaka, A., Kormos, L. L., Koshio, Y., Koto, T., Kowalik, K., Kudenko, Y., Kudo, Y., Kuribayashi, S., Kurjata, R., Kurochka, V., Kutter, T., Kuze, M., Kwon, E., La Commara, M., Labarga, L., Lachat, M., Lachner, K., Lagoda, J., Lakshmi, S. M., LamersJames, M., Langella, A., Laporte, J. -F., Last, D., Latham, N., Laveder, M., Lavitola, L., Lawe, M., Learned, J. G., Lee, Y., Lee, S. H., Silverio, D. Leon, Levorato, S., Lewis, S., Li, X., Li, W., Lin, C., Litchfield, R. P., Liu, S. L., Liu, Y. M., Long, K. R., Longhin, A., Moreno, A. Lopez, Lu, X., Ludovici, L., Lux, T., Machado, L. N., Maekawa, Y., Magaletti, L., Mahn, K., Mahtani, K. K., Malek, M., Mandal, M., Manly, S., Marino, A. D., Martens, K., Marti, Ll., Martin, D. G. R., Martin, J. F., Martin, D., Martini, M., Maruyama, T., Matsubara, T., Matsumoto, R., Mattiazzi, M., Matveev, V., Mauger, C., Mavrokoridis, K., Mazzucato, E., McCauley, N., McElwee, J. M., McFarland, K. S., McGrew, C., McKean, J., Mefodiev, A., Megias, G. D., Mehta, P., Mellet, L., Menjo, H., Metelko, C., Mezzetto, M., Migenda, J., Mijakowski, P., Miki, S., Miller, E., Minamino, A., Mine, S., Mineev, O., Mirabito, J., Miura, M., Bueno, L. Molina, Moon, D. H., Mori, M., Moriyama, S., Morrison, P., Muñoz, A., Mueller, Th. A., Munford, D., Munteanu, L., Nagai, Y., Nagai, K., Nakadaira, T., Nakagiri, K., Nakahata, M., Nakajima, Y., Nakamura, A., Nakamura, K., Nakamura, K. D., Nakamura, T., Nakanishi, F., Nakano, Y., Nakaya, T., Nakayama, S., Nakayoshi, K., Naseby, C. E. R., Ngoc, T. V., Nguyen, V. Q., Nguyen, D. T., Nicholson, M., Niewczas, K., Ninomiya, K., Nishijima, K., Nishimori, S., Nishimura, Y., Noguchi, Y., Nosek, T., Nova, F., Novella, P., Nugent, J. C., Odagawa, T., Okazaki, R., Okazawa, H., Okinaga, W., Okumura, K., Okusawa, T., Ommura, Y., Onda, N., Ospina, N., Osu, L., Oyama, Y., O'Flaherty, M., O'Keeffe, H. M., O'Sullivan, L., Périssé, L., Paganini, P., Palladino, V., Paolone, V., Pari, M., Park, R. G., Parlone, J., Pasternak, J., Payne, D., Penn, G. C., de Perio, P., Pershey, D., Pfaff, M., Pickering, L., Pintaudi, G., Pistillo, C., Pointon, B. W., Popov, B., Yrey, A. Portocarrero, Porwit, K., Posiadala-Zezula, M., Prabhu, Y. S., Prasad, H., Pronost, G., Prouse, N. W., Pupilli, F., Quilain, B., Quyen, P. T., Raaf, J. L., Radermacher, T., Radicioni, E., Radics, B., Ramirez, M. A., Ramsden, R. M., Ratoff, P. N., Reh, M., Riccio, C., Richards, B., Rogly, R., Rondio, E., Roth, S., Roy, N., Rubbia, A., Russo, L., Rychter, A., Saenz, W., Sakai, S., Sakashita, K., Samani, S., Santos, A. D., Sato, Y., Sato, K., Schefke, T., Schloesser, C. M., Scholberg, K., Scott, M., Seiya, Y., Sekiguchi, T., Sekiya, H., Seo, J. W., Sgalaberna, D., Shaikhiev, A., Shi, W., Shiba, H., Shibayama, R., Shigeta, N., Shima, S., Shimamura, R., Shimizu, K., Shinoki, M., Shiozawa, M., Shiraishi, Y., Shvartsman, A., Skrobova, N., Skwarczynski, K., Smy, M. B., Smyczek, D., Sobczyk, J. T., Sobel, H. W., Soler, F. J. P., Sonoda, Y., Speers, A. J., Spina, R., Stroke, Y., Suslov, I. A., Suvorov, S., Suzuki, S., Suzuki, A., Suzuki, S. Y., Suzuki, Y., Sánchez, F., Tada, T., Tada, M., Tairafune, S., Takagi, Y., Takeda, A., Takemoto, Y., Takeuchi, Y., Takhistov, V., Takifuji, K., Tanaka, H., Tanaka, H. K., Tanigawa, H., Taniuchi, N., Tano, T., Tarrant, A., Tashiro, T., Teklu, A., Terada, K., Tereshchenko, V. V., Thamm, N., Thiesse, M. D., Thompson, L. F., Toki, W., Tomiya, T., Touramanis, C., Tsui, K. M., Tsukamoto, T., Tzanov, M., Uchida, Y., Vagins, M. R., Vargas, D., Varghese, M., Vasseur, G., Villa, E., Vinning, W. G. S., Virginet, U., Vladisavljevic, T., Wachala, T., Wakabayashi, D., Wallace, H. T., Walsh, J. G., Walter, C. W., Wan, L., Wang, X., Wang, Y., Wark, D., Wascko, M. O., Watanabe, E., Weber, A., Wendell, R. A., Wester, T., Wilking, M. J., Wilkinson, C., Wilson, S. T., Wilson, J. R., Wood, K., Wret, C., Wu, Y., Xia, J., Xie, Z., Xu, B. D., Xu, Y. -H., Yamamoto, K., Yamamoto, T., Yamauchi, K., Yanagisawa, C., Yang, G., Yang, B. S., Yang, J. Y., Yankelevich, A., Yano, T., Yasutome, K., Yershov, N., Yevarouskaya, U., Yokoyama, M., Yoo, J., Yoshida, T., Yoshida, S., Yoshimoto, Y., Yoshimura, N., Yoshioka, Y., Yu, M., Yu, I., Zaki, R., Zaldivar, B., Zalewska, A., Zalipska, J., Zaremba, K., Zarnecki, G., Zhang, J., Zhang, A. Q., Zhang, B., Zhao, X. Y., Zhong, H., Zhu, T., Ziembicki, M., Zimmerman, E. D., Zito, M., and Zsoldos, S.
Subjects: High Energy Physics - Experiment
Abstract: The Super-Kamiokande and T2K collaborations present a joint measurement of neutrino oscillation parameters from their atmospheric and beam neutrino data. It uses a common interaction model for events overlapping in neutrino energy and correlated detector systematic uncertainties between the two datasets, which are found to be compatible. Using 3244.4 days of atmospheric data and a beam exposure of $19.7(16.3) \times 10^{20}$ protons on target in (anti)neutrino mode, the analysis finds a 1.9$\sigma$ exclusion of CP-conservation (defined as $J_{CP}=0$) and a preference for the normal mass ordering., Comment: 12 pages, 4 figures
Published: 2024

4. Development of a data overflow protection system for Super-Kamiokande to maximize data from nearby supernovae

Author: Mori, M., Abe, K., Hayato, Y., Hiraide, K., Hosokawa, K., Ieki, K., Ikeda, M., Kameda, J., Kanemura, Y., Kaneshima, R., Kashiwagi, Y., Kataoka, Y., Miki, S., Mine, S., Miura, M., Moriyama, S., Nakano, Y., Nakahata, M., Nakayama, S., Noguchi, Y., Okamoto, K., Sato, K., Sekiya, H., Shiba, H., Shimizu, K., Shiozawa, M., Sonoda, Y., Suzuki, Y., Takeda, A., Takemoto, Y., Takenaka, A., Tanaka, H., Watanabe, S., Yano, T., Han, S., Kajita, T., Okumura, K., Tashiro, T., Tomiya, T., Wang, X., Yoshida, S., Megias, G. D., Fernandez, P., Labarga, L., Ospina, N., Zaldivar, B., Pointon, B. W., Kearns, E., Raaf, J. L., Wan, L., Wester, T., Bian, J., Griskevich, N. J., Locke, S., Smy, M. B., Sobel, H. W., Takhistov, V., Yankelevich, A., Hill, J., Jang, M. C., Lee, S. H., Moon, D. H., Park, R. G., Bodur, B., Scholberg, K., Walter, C. W., Beauchene, A., Drapier, O., Giampaolo, A., Mueller, Th. A., Santos, A. D., Paganini, P., Quilain, B., Rogly, R., Ishizuka, T., Nakamura, T., Jang, J. S., Learned, J. G., Choi, K., Iovine, N., Cao, S., Anthony, L. H. V., Martin, D., Scott, M., Sztuc, A. A., Uchida, Y., Berardi, V., Catanesi, M. G., Radicioni, E., Calabria, N. F., Langella, A., Machado, L. N., De Rosa, G., Collazuol, G., Iacob, F., Lamoureux, M., Mattiazzi, M., Ludovici, L., Gonin, M., Perisse, L., Pronost, G., Fujisawa, C., Maekawa, Y., Nishimura, Y., Okazaki, R., Akutsu, R., Friend, M., Hasegawa, T., Ishida, T., Kobayashi, T., Jakkapu, M., Matsubara, T., Nakadaira, T., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Bhuiyan, N., Burton, G. T., Edwards, R., Di Lodovico, F., Gao, J., Goldsack, A., Katori, T., Migenda, J., Ramsden, R. M., Xie, Z., Zsoldos, S., Kotsar, Y., Ozaki, H., Suzuki, A. T., Takagi, Y., Takeuchi, Y., Zhong, H., Bronner, C., Feng, J., Hu, J. R., Hu, Z., Kawaune, M., Kikawa, T., LiCheng, F., Nakaya, T., Wendell, R. A., Yasutome, K., Jenkins, S. J., McCauley, N., Mehta, P., Tarant, A., Fukuda, Y., Itow, Y., Menjo, H., Ninomiya, K., Yoshioka, Y., Lagoda, J., Lakshmi, S. M., Mandal, M., Mijakowski, P., Prabhu, Y. S., Zalipska, J., Jia, M., Jiang, J., Jung, C. K., Shi, W., Wilking, M. J., Yanagisawa, C., Harada, M., Hino, Y., Ishino, H., Kitagawa, H., Koshio, Y., Nakanishi, F., Sakai, S., Tada, T., Tano, T., Barr, G., Barrow, D., Cook, L., Samani, S., Wark, D., Holin, A., Nova, F., Jung, S., Yang, B. S., Yang, J. Y., Yoo, J., Fannon, J. E. P., Kneale, L., Malek, M., McElwee, J. M., Thiesse, M. D., Thompson, L. F., Wilson, S., Okazawa, H., Kim, S. B., Kwon, E., Seo, J. W., Yu, I., Ichikawa, A. K., Nakamura, K. D., Tairafune, S., Nishijima, K., Eguchi, A., Nakagiri, K., Nakajima, Y., Shima, S., Taniuchi, N., Watanabe, E., Yokoyama, M., de Perio, P., Fujita, S., Martens, K., Tsui, K. M., Vagins, M. R., Valls, C. J., Xia, J., Kuze, M., Izumiyama, S., Ishitsuka, M., Ito, H., Kinoshita, T., Matsumoto, R., Ommura, Y., Shigeta, N., Shinoki, M., Suganuma, T., Yamauchi, K., Yoshida, T., Martin, J. F., Tanaka, H. A., Towstego, T., Gaur, R., Gousy-Leblanc, V., Hartz, M., Konaka, A., Li, X., Prouse, N. W., Chen, S., Xu, B. D., Zhang, B., Posiadala-Zezula, M., Boyd, S. B., Hadley, D., Nicholson, M., Flaherty, M. O', Richards, B., Ali, A., Jamieson, B., Amanai, S., Marti, Ll., Minamino, A., Pintaudi, G., Sano, S., Suzuki, S., and Wada, K.
Subjects: Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Solar and Stellar Astrophysics, High Energy Physics - Experiment
Abstract: Neutrinos from very nearby supernovae, such as Betelgeuse, are expected to generate more than ten million events over 10\,s in Super-Kamokande (SK). At such large event rates, the buffers of the SK analog-to-digital conversion board (QBEE) will overflow, causing random loss of data that is critical for understanding the dynamics of the supernova explosion mechanism. In order to solve this problem, two new DAQ modules were developed to aid in the observation of very nearby supernovae. The first of these, the SN module, is designed to save only the number of hit PMTs during a supernova burst and the second, the Veto module, prescales the high rate neutrino events to prevent the QBEE from overflowing based on information from the SN module. In the event of a very nearby supernova, these modules allow SK to reconstruct the time evolution of the neutrino event rate from beginning to end using both QBEE and SN module data. This paper presents the development and testing of these modules together with an analysis of supernova-like data generated with a flashing laser diode. We demonstrate that the Veto module successfully prevents DAQ overflows for Betelgeuse-like supernovae as well as the long-term stability of the new modules. During normal running the Veto module is found to issue DAQ vetos a few times per month resulting in a total dead time less than 1\,ms, and does not influence ordinary operations. Additionally, using simulation data we find that supernovae closer than 800~pc will trigger Veto module resulting in a prescaling of the observed neutrino data., Comment: 28 pages, 18 figures. Submitted to PTEP
Published: 2024
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5. Evaluation of the performance of the event reconstruction algorithms in the JSNS$^2$ experiment using a $^{252}$Cf calibration source

Author: Lee, D. H., Cheoun, M. K., Choi, J. H., Choi, J. Y., Dodo, T., Goh, J., Haga, K., Harada, M., Hasegawa, S., Hwang, W., Iida, T., Jang, H. I., Jang, J. S., Joo, K. K., Jung, D. E., Kang, S. K., Kasugai, Y., Kawasaki, T., Kim, E. J., Kim, J. Y., Kim, S. B, Kim, W., Kinoshita, H., Konno, T., Lim, I. T., Little, C., Marzec, E., Maruyama, T., Masuda, S., Meigo, S., Moon, D. H., Nakano, T., Niiyama, M., Nishikawa, K., Pac, M. Y., Park, H. W., Park, J. S., Park, R. G., Peeters, S. J. M., Rott, C., Sakai, K., Sakamoto, S., Shima, T., Spitz, J., Suekane, F., Sugaya, Y., Suzuya, K., Takeuchi, Y., Yamaguchi, Y., Yeh, M., Yeo, I. S., Yoo, C., and Yu, I.
Subjects: High Energy Physics - Experiment, Physics - Instrumentation and Detectors
Abstract: JSNS$^2$ searches for short baseline neutrino oscillations with a baseline of 24~meters and a target of 17~tonnes of the Gd-loaded liquid scintillator. The correct algorithm on the event reconstruction of events, which determines the position and energy of neutrino interactions in the detector, are essential for the physics analysis of the data from the experiment. Therefore, the performance of the event reconstruction is carefully checked with calibrations using $^{252}$Cf source. This manuscript describes the methodology and the performance of the event reconstruction.
Published: 2024

6. Pulse Shape Discrimination in JSNS$^2$

Author: Dodo, T., Cheoun, M. K., Choi, J. H., Choi, J. Y., Goh, J., Haga, K., Harada, M., Hasegawa, S., Hwang, W., Iida, T., Jang, H. I., Jang, J. S., Joo, K. K., Jung, D. E., Kang, S. K., Kasugai, Y., Kawasaki, T., Kim, E. J., Kim, J. Y., Kim, S. B., Kim, W., Kinoshita, H., Konno, T., Lee, D. H., Lim, I. T., Little, C., Marzec, E., Maruyama, T., Masuda, S., Meigo, S., Moon, D. H., Nakano, T., Niiyama, M., Nishikawa, K., Pac, M. Y., Park, H. W., Park, J. S., Park, R. G., Peeters, S. J. M., Rott, C., Sakai, K., Sakamoto, S., Shima, T., Shin, C. D., Spitz, J., Suekane, F., Sugaya, Y., Suzuya, K., Takeuchi, Y., Yamaguchi, Y., Yeh, M., Yeo, I. S., Yoo, C., and Yu, I.
Subjects: Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract: JSNS$^2$ (J-PARC Sterile Neutrino Search at J-PARC Spallation Neutron Source) is an experiment that is searching for sterile neutrinos via the observation of $\bar{\nu}_{\mu} \rightarrow \bar{\nu}_e$ appearance oscillations using neutrinos with muon decay-at-rest. For this search, rejecting cosmic-ray-induced neutron events by Pulse Shape Discrimination (PSD) is essential because the JSNS$^2$ detector is located above ground, on the third floor of the building. We have achieved 95$\%$ rejection of neutron events while keeping 90$\%$ of signal, electron-like events using a data driven likelihood method., Comment: arXiv admin note: text overlap with arXiv:2111.07482, arXiv:2308.02722
Published: 2024

7. Measurements of the charge ratio and polarization of cosmic-ray muons with the Super-Kamiokande detector

Author: Kitagawa, H., Tada, T., Abe, K., Bronner, C., Hayato, Y., Hiraide, K., Hosokawa, K., Ieki, K., Ikeda, M., Kameda, J., Kanemura, Y., Kaneshima, R., Kashiwagi, Y., Kataoka, Y., Miki, S., Mine, S., Miura, M., Moriyama, S., Nakano, Y., Nakahata, M., Nakayama, S., Noguchi, Y., Okamoto, K., Sato, K., Sekiya, H., Shiba, H., Shimizu, K., Shiozawa, M., Sonoda, Y., Suzuki, Y., Takeda, A., Takemoto, Y., Takenaka, A., Tanaka, H., Watanabe, S., Yano, T., Han, S., Kajita, T., Okumura, K., Tashiro, T., Tomiya, T., Wang, X., Yoshida, S., Megias, G. D., Fernandez, P., Labarga, L., Ospina, N., Zaldivar, B., Pointon, B. W., Kearns, E., Raaf, J. L., Wan, L., Wester, T., Bian, J., Griskevich, N. J., Locke, S., Smy, M. B., Sobel, H. W., Takhistov, V., Yankelevich, A., Hill, J., Jang, M. C., Lee, S. H., Moon, D. H., Park, R. G., Bodur, B., Scholberg, K., Walter, C. W., Beauchêne, A., Drapier, O., Giampaolo, A., Mueller, Th. A., Santos, A. D., Paganini, P., Quilain, B., Rogly, R., Nakamura, T., Jang, J. S., Machado, L. N., Learned, J. G., Choi, K., Iovine, N., Cao, S., Anthony, L. H. V., Martin, D., Prouse, N. W., Scott, M., Sztuc, A. A., Uchida, Y., Berardi, V., Calabria, N. F., Catanesi, M. G., Radicioni, E., Langella, A., De Rosa, G., Collazuol, G., Iacob, F., Lamoureux, M., Mattiazzi, M., Ludovici, L., Gonin, M., Périssé, L., Pronost, G., Fujisawa, C., Maekawa, Y., Nishimura, Y., Okazaki, R., Akutsu, R., Friend, M., Hasegawa, T., Ishida, T., Kobayashi, T., Jakkapu, M., Matsubara, T., Nakadaira, T., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Bhuiyan, N., Burton, G. T., Di Lodovico, F., Gao, J., Goldsack, A., Katori, T., Migenda, J., Ramsden, R. M., Xie, Z., Zsoldos, S., Kotsar, Y., Ozaki, H., Suzuki, A. T., Takagi, Y., Takeuchi, Y., Zhong, H., Feng, J., Feng, L., Hu, J. R., Hu, Z., Kawaue, M., Kikawa, T., Mori, M., Nakaya, T., Wendell, R. A., Yasutome, K., Jenkins, S. J., McCauley, N., Mehta, P., Tarant, A., Wilking, M. J., Fukuda, Y., Itow, Y., Menjo, H., Ninomiya, K., Yoshioka, Y., Lagoda, J., Mandal, M., Mijakowski, P., Prabhu, Y. S., Zalipska, J., Jia, M., Jiang, J., Jung, C. K., Shi, W., Yanagisawa, C., Harada, M., Hino, Y., Ishino, H., Koshio, Y., Nakanishi, F., Sakai, S., Tano, T., Ishizuka, T., Barr, G., Barrow, D., Cook, L., Samani, S., Wark, D., Holin, A., Nova, F., Jung, S., Yang, B. S., Yang, J. Y., Yoo, J., Fannon, J. E. P., Kneale, L., Malek, M., McElwee, J. M., Thiesse, M. D., Thompson, L. F., Wilson, S. T., Okazawa, H., Lakshmi, S. M., Kim, S. B., Kwon, E., Seo, J. W., Yu, I., Ichikawa, A. K., Nakamura, K. D., Tairafune, S., Nishijima, K., Eguchi, A., Nakagiri, K., Nakajima, Y., Shima, S., Taniuchi, N., Watanabe, E., Yokoyama, M., de Perio, P., Fujita, S., Jesús-Valls, C., Martens, K., Tsui, K. M., Vagins, M. R., Xia, J., Izumiyama, S., Kuze, M., Matsumoto, R., Terada, K., Ishitsuka, M., Ito, H., Kinoshita, T., Ommura, Y., Shigeta, N., Shinoki, M., Suganuma, T., Yamauchi, K., Yoshida, T., Martin, J. F., Tanaka, H. A., Towstego, T., Gaur, R., Gousy-Leblanc, V., Hartz, M., Konaka, A., Li, X., Chen, S., Xu, B. D., Zhang, B., Posiadala-Zezula, M., Boyd, S. B., Edwards, R., Hadley, D., Nicholson, M., O'Flaherty, M., Richards, B., Ali, A., Jamieson, B., Amanai, S., Marti, Ll., Minamino, A., Pintaudi, G., Sano, S., Suzuki, S., and Wada, K.
Subjects: High Energy Physics - Experiment, Astrophysics - High Energy Astrophysical Phenomena
Abstract: We present the results of the charge ratio ($R$) and polarization ($P^{\mu}_{0}$) measurements using the decay electron events collected from 2008 September to 2022 June by the Super-Kamiokande detector. Because of its underground location and long operation, we performed high precision measurements by accumulating cosmic-ray muons. We measured the muon charge ratio to be $R=1.32 \pm 0.02$ $(\mathrm{stat.}{+}\mathrm{syst.})$ at $E_{\mu}\cos \theta_{\mathrm{Zenith}}=0.7^{+0.3}_{-0.2}$ $\mathrm{TeV}$, where $E_{\mu}$ is the muon energy and $\theta_{\mathrm{Zenith}}$ is the zenith angle of incoming cosmic-ray muons. This result is consistent with the Honda flux model while this suggests a tension with the $\pi K$ model of $1.9\sigma$. We also measured the muon polarization at the production location to be $P^{\mu}_{0}=0.52 \pm 0.02$ $(\mathrm{stat.}{+}\mathrm{syst.})$ at the muon momentum of $0.9^{+0.6}_{-0.1}$ $\mathrm{TeV}/c$ at the surface of the mountain; this also suggests a tension with the Honda flux model of $1.5\sigma$. This is the most precise measurement ever to experimentally determine the cosmic-ray muon polarization near $1~\mathrm{TeV}/c$. These measurement results are useful to improve the atmospheric neutrino simulations., Comment: 29 pages, 45 figures
Published: 2024
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8. Second gadolinium loading to Super-Kamiokande

Author: Abe, K., Bronner, C., Hayato, Y., Hiraide, K., Hosokawa, K., Ieki, K., Ikeda, M., Kameda, J., Kanemura, Y., Kaneshima, R., Kashiwagi, Y., Kataoka, Y., Miki, S., Mine, S., Miura, M., Moriyama, S., Nakano, Y., Nakahata, M., Nakayama, S., Noguchi, Y., Sato, K., Sekiya, H., Shiba, H., Shimizu, K., Shiozawa, M., Sonoda, Y., Suzuki, Y., Takeda, A., Takemoto, Y., Tanaka, H., Yano, T., Han, S., Kajita, T., Okumura, K., Tashiro, T., Tomiya, T., Wang, X., Yoshida, S., Fernandez, P., Labarga, L., Ospina, N., Zaldivar, B., Pointon, B. W., Kearns, E., Raaf, J. L., Wan, L., Wester, T., Bian, J., Griskevich, N. J., Smy, M. B., Sobel, H. W., Takhistov, V., Yankelevich, A., Hill, J., Jang, M. C., Lee, S. H., Moon, D. H., Park, R. G., Bodur, B., Scholberg, K., Walter, C. W., Beauchene, A., Drapier, O., Giampaolo, A., Mueller, Th. A., Santos, A. D., Paganini, P., Quilain, B., Rogly, R., Nakamura, T., Jang, J. S., Machado, L. N., Learned, J. G., Choi, K., Iovine, N., Cao, S., Anthony, L. H. V., Martin, D., Prouse, N. W., Scott, M., Uchida, Y., Berardi, V., Calabria, N. F., Catanesi, M. G., Radicioni, E., Langella, A., De Rosa, G., Collazuol, G., Iacob, F., Mattiazzi, M., Ludovici, L., Gonin, M., Perisse, L., Pronost, G., Fujisawa, C., Maekawa, Y., Nishimura, Y., Okazaki, R., Akutsu, R., Friend, M., Hasegawa, T., Ishida, T., Kobayashi, T., Jakkapu, M., Matsubara, T., Nakadaira, T., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Bhuiyan, N., Burton, G. T., Di Lodovico, F., Gao, J., Goldsack, A., Katori, T., Migenda, J., Ramsden, R. M., Xie, Z., Zsoldos, S., Suzuki, A. T., Takagi, Y., Takeuchi, Y., Zhong, H., Feng, J., Feng, L., Hu, J. R., Hu, Z., Kawaue, M., Kikawa, T., Mori, M., Nakaya, T., Wendell, R. A., Yasutome, K., Jenkins, S. J., McCauley, N., Mehta, P., Tarant, A., Wilking, M. J., Fukuda, Y., Itow, Y., Menjo, H., Ninomiya, K., Yoshioka, Y., Lagoda, J., Mandal, M., Mijakowski, P., Prabhu, Y. S., Zalipska, J., Jia, M., Jiang, J., Shi, W., Yanagisawa, C., Harada, M., Hino, Y., Ishino, H., Koshio, Y., Nakanishi, F., Sakai, S., Tada, T., Tano, T., Ishizuka, T., Barr, G., Barrow, D., Cook, L., Samani, S., Wark, D., Holin, A., Nova, F., Jung, S., Yang, B. S., Yang, J. Y., Yoo, J., Fannon, J. E. P., Kneale, L., Malek, M., McElwee, J. M., Thiesse, M. D., Thompson, L. F., Wilson, S. T., Okazawa, H., Lakshmi, S. M., Kim, S. B., Kwon, E., Seo, J. W., Yu, I., Ichikawa, A. K., Tairafune, S., Nishijima, K., Eguchi, A., Nakagiri, K., Nakajima, Y., Shima, S., Taniuchi, N., Watanabe, E., Yokoyama, M., de Perio, P., Fujita, S., Jesus-Valls, C., Martens, K., Tsui, K. M., Vagins, M. R., Xia, J., Izumiyama, S., Kuze, M., Matsumoto, R., Terada, K., Ishitsuka, M., Ito, H., Ommura, Y., Shigeta, N., Shinoki, M., Yamauchi, K., Yoshida, T., Gaur, R., Gousy-Leblanc, V., Hartz, M., Konaka, A., Li, X., Chen, S., Xu, B. D., Zhang, B., Posiadala-Zezula, M., Boyd, S. B., Edwards, R., Hadley, D., Nicholson, M., O'Flaherty, M., Richards, B., Ali, A., Jamieson, B., Amanai, S., Marti, Ll., Minamino, A., Suzuki, S., Scovell, P. R., Meehan, E., Bandac, I., Pena-Garay, C., Perez, J., Gileva, O., Lee, E. K., Leonard, D. S., Sakakieda, Y., Sakaguchi, A., Sueki, K., Takaku, Y., and Yamasaki, S.
Subjects: Physics - Instrumentation and Detectors, Astrophysics - High Energy Astrophysical Phenomena
Abstract: The first loading of gadolinium (Gd) into Super-Kamiokande in 2020 was successful, and the neutron capture efficiency on Gd reached 50\%. To further increase the Gd neutron capture efficiency to 75\%, 26.1 tons of $\rm Gd_2(\rm SO_4)_3\cdot \rm 8H_2O$ was additionally loaded into Super-Kamiokande (SK) from May 31 to July 4, 2022. As the amount of loaded $\rm Gd_2(\rm SO_4)_3\cdot \rm 8H_2O$ was doubled compared to the first loading, the capacity of the powder dissolving system was doubled. We also developed new batches of gadolinium sulfate with even further reduced radioactive impurities. In addition, a more efficient screening method was devised and implemented to evaluate these new batches of $\rm Gd_2(\rm SO_4)_3\cdot \rm 8H_2O$. Following the second loading, the Gd concentration in SK was measured to be $333.5\pm2.5$ ppm via an Atomic Absorption Spectrometer (AAS). From the mean neutron capture time constant of neutrons from an Am/Be calibration source, the Gd concentration was independently measured to be 332.7 $\pm$ 6.8(sys.) $\pm$ 1.1(stat.) ppm, consistent with the AAS result. Furthermore, during the loading the Gd concentration was monitored continually using the capture time constant of each spallation neutron produced by cosmic-ray muons,and the final neutron capture efficiency was shown to become 1.5 times higher than that of the first loaded phase, as expected., Comment: 34 pages, 13 figures, submitted to Nuclear Inst. and Methods in Physics Research, A
Published: 2024
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9. Performance of SK-Gd's Upgraded Real-time Supernova Monitoring System

Author: Kashiwagi, Y., Abe, K., Bronner, C., Hayato, Y., Hiraide, K., Hosokawa, K., Ieki, K., Ikeda, M., Kameda, J., Kanemura, Y., Kaneshima, R., Kataoka, Y., Miki, S., Mine, S., Miura, M., Moriyama, S., Nakano, Y., Nakahata, M., Nakayama, S., Noguchi, Y., Sato, K., Sekiya, H., Shiba, H., Shimizu, K., Shiozawa, M., Sonoda, Y., Suzuki, Y., Takeda, A., Takemoto, Y., Tanaka, H., Yano, T., Han, S., Kajita, T., Okumura, K., Tashiro, T., Tomiya, T., Wang, X., Yoshida, S., Fernandez, P., Labarga, L., Ospina, N., Zaldivar, B., Pointn, B. W., Kearns, E., Raaf, J. L., Wan, L., Wester, T., Bian, J., Griskevich, N. J., Locke, S., Smy, M. B., Sobel, H. W., Takhistov, V., Yankelevich, A., Hill, J., Jang, M. C., Lee, S. H., Moon, D. H., Park, R. G., Bodur, B., Scholberg, K., Walter, C. W., Beauchêne, A., Drapier, O., Giampaolo, A., Mueller, Th. A., Santos, A. D., Paganini, P., Quilain, B., Rogly, R., Nakamura, T., Jang, J. S., Machado, L. N., Learned, J. G., Choi, K., Iovine, N., Cao, S., Anthony, L. H. V., Martin, D., Prouse, N. W., Scott, M., Sztuc, A. A., Uchida, Y., Berardi, V., Catanesi, M. G., Radicioni, E., Calabria, N. F., Langella, A., De Rosa, G., Collazuol, G., Iacob, F., Mattiazzi, M., Ludovici, L., Gonin, M., Périssé, L., Pronost, G., Fujisawa, C., Maekawa, Y., Nishimura, Y., Okazaki, R., Akutsu, R., Friend, M., Hasegawa, T., Ishida, T., Kobayashi, T., Jakkapu, M., Matsubara, T., Nakadaira, T., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Bhuiyan, N., Burton, G. T., Di Lodovico, F., Gao, J., Goldsack, A., Katori, T., Migenda, J., Ramsden, R. M., Xie, Z., Zsoldos, S., Suzuki, A. T., Takagi, Y., Takeuchi, Y., Zhong, H., Feng, J., Feng, L., Hu, J. R., Hu, Z., Kawaue, M., Kikawa, T., Mori, M., Nakaya, T., Wendell, R. A., Yasutome, K., Jenkins, S. J., McCauley, N., Mehta, P., Tarrant, A., Fukuda, Y., Itow, Y., Menjo, H., Ninomiya, K., Yoshioka, Y., Lagoda, J., Lakshmi, S. M., Mandal, M., Mijakowski, P., Prabhu, Y. S., Zalipska, J., Jia, M., Jiang, J., Jung, C. K., Shi, W., Wilking, M. J., Yanagisawa, C., Harada, M., Hino, Y., Ishino, H., Koshio, Y., Nakanishi, F., Sakai, S., Tada, T., Tano, T., Ishizuka, T., Barr, G., Barrow, D., Cook, L., Samani, S., Wark, D., Holin, A., Nova, F., Jung, S., Yang, B. S., Yang, J. Y., Yoo, J., Fannon, J. E. P., Kneale, L., Malek, M., McElwee, J. M., Thiesse, M. D., Thompson, L. F., Wilson, S. T., Okazawa, H., Kim, S. B., Kwon, E., Seo, J. W., Yu, I., Ichikawa, A. K., Nakamura, K. D., Tairafune, S., Nishijima, K., Eguchi, A., Nakagiri, K., Nakajima, Y., Shima, S., Taniuchi, N., Watanabe, E., Yokoyama, M., de Perio, P., Fujita, S., Jesús-Valls, C., Martens, K., Tsui, K. M., Vagins, M. R., Xia, J., Kuze, M., Izumiyama, S., Matsumoto, R., Ishitsuka, M., Ito, H., Ommura, Y., Shigeta, N., Shinoki, M., Yamauchi, K., Yoshida, T., Gaur, R., Gousy-Leblanc, V., Hartz, M., Konaka, A., Li, X., Chen, S., Xu, B. D., Zhang, B., Posiadala-Zezula, M., Boyd, S. B., Edwards, R., Hadley, D., Nicholson, M., O'Flaherty, M., Richards, B., Ali, A., Jamieson, B., Amanai, S., Marti, Ll., Minamino, A., and Suzuki, S.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Among multi-messenger observations of the next galactic core-collapse supernova, Super-Kamiokande (SK) plays a critical role in detecting the emitted supernova neutrinos, determining the direction to the supernova (SN), and notifying the astronomical community of these observations in advance of the optical signal. On 2022, SK has increased the gadolinium dissolved in its water target (SK-Gd) and has achieved a Gd concentration of 0.033%, resulting in enhanced neutron detection capability, which in turn enables more accurate determination of the supernova direction. Accordingly, SK-Gd's real-time supernova monitoring system (Abe te al. 2016b) has been upgraded. SK_SN Notice, a warning system that works together with this monitoring system, was released on December 13, 2021, and is available through GCN Notices (Barthelmy et al. 2000). When the monitoring system detects an SN-like burst of events, SK_SN Notice will automatically distribute an alarm with the reconstructed direction to the supernova candidate within a few minutes. In this paper, we present a systematic study of SK-Gd's response to a simulated galactic SN. Assuming a supernova situated at 10 kpc, neutrino fluxes from six supernova models are used to characterize SK-Gd's pointing accuracy using the same tools as the online monitoring system. The pointing accuracy is found to vary from 3-7$^\circ$ depending on the models. However, if the supernova is closer than 10 kpc, SK_SN Notice can issue an alarm with three-degree accuracy, which will benefit follow-up observations by optical telescopes with large fields of view., Comment: 38 pages, 29 figures, 6 tables
Published: 2024

10. Solar neutrino measurements using the full data period of Super-Kamiokande-IV

Author: Collaboration, Super-Kamiokande, Abe, K., Bronner, C., Hayato, Y., Hiraide, K., Hosokawa, K., Ieki, K., Ikeda, M., Imaizumi, S., Iyogi, K., Kameda, J., Kanemura, Y., Kaneshima, R., Kashiwagi, Y., Kataoka, Y., Kato, Y., Kishimoto, Y., Miki, S., Mine, S., Miura, M., Mochizuki, T., Moriyama, S., Nagao, Y., Nakahata, M., Nakano, Y., Nakayama, S., Noguchi, Y., Okada, T., Okamoto, K., Orii, A., Sato, K., Sekiya, H., Shiba, H., Shimizu, K., Shiozawa, M., Sonoda, Y., Suzuki, Y., Takeda, A., Takemoto, Y., Takenaka, A., Tanaka, H., Watanabe, S., Yano, T., Han, S., Kajita, T., Okumura, K., Tashiro, T., Tomiya, T., Wang, R., Wang, X., Yoshida, S., Bravo-Berguno, D., Fernandez, P., Labarga, L., Ospina, N., Zaldivar, B., Pointon, B. W., Blaszczyk, F. d. M., Kachulis, C., Kearns, E., Raaf, J. L., Stone, J. L., Wan, L., Wester, T., Bian, J., Griskevich, N. J., Kropp, W. R., Locke, S., Smy, M. B., Sobel, H. W., Takhistov, V., Weatherly, P., Yankelevich, A., Ganezer, K. S., Hill, J., Jang, M. C., Kim, J. Y., Lee, S., Lim, I. T., Moon, D. H., Park, R. G., Bodur, B., Scholberg, K., Walter, C. W., Beauchene, A., Bernard, L., Coffani, A., Drapier, O., Hedri, S. El, Giampaolo, A., Imber, J., Mueller, Th. A., Paganini, P., Rogly, R., Quilain, B., Santos, A., Nakamura, T., Jang, J. S., Machado, L. N., Learned, J. G., Matsuno, S., Iovine, N., Choi, K., Cao, S., Anthony, L. H. V., Litchfield, R. P., Prouse, N., Marin, D., Scott, M., Sztuc, A. A., Uchida, Y., Berardi, V., Catanesi, M. G., Intonti, R. A., Radicioni, E., Calabria, N. F., De Rosa, G., Langella, A., Collazuol, G., Iacob, F., Lamoureux, M., Mattiazzi, M., Ludovici, L., Gonin, M., Perisse, L., Pronost, G., Fujisawa, C., Maekawa, Y., Nishimura, Y., Okazaki, R., Friend, M., Hasegawa, T., Ishida, T., Jakkapu, M., Kobayashi, T., Matsubara, T., Nakadaira, T., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Boschi, T., Bhuiyan, N., Burton, G. T., Gao, J., Goldsack, A., Katori, T., Di Lodovico, F., Migenda, J., Sedgwick, S. Molina, Ramsden, R. M., Taani, M., Xie, Z., Zsoldos, S., Abe, KE., Hasegawa, M., Isobe, Y., Kotsar, Y., Miyabe, H., Ozaki, H., Shiozawa, T., Sugimoto, T., Suzuki, A. T., Takagi, Y., Takeuchi, Y., Yamamoto, S., Zhong, H., Ashida, Y., Feng, J., Feng, L., Hayashino, T., Hirota, S., Hu, J. R., Hu, Z., Jiang, M., Kawaue, M., Kikawa, T., Mori, M., Nakamura, KE., Nakaya, T., Wendell, R. A., Yasutome, K., Jenkins, S. J., McCauley, N., Mehta, P., Pritchard, A., Tarrant, A., Wilking, M. J., Fukuda, Y., Itow, Y., Menjo, H., Murase, M., Ninomiya, K., Niwa, T., Tsukada, M., Yoshioka, Y., Frankiewicz, K., Lagoda, J., Mandal, M., Mijakowski, P., Prabhu, Y. S., Zalipska, J., Jiang, J., Jia, M., Jung, C. K., Palomino, J. L., Santucci, G., Shi, W., Vilela, C., Yanagisawa, C., Fukuda, D., Hagiwara, K., Harada, M., Hino, Y., Horai, T., Ishino, H., Ito, S., Kitagawa, H., Koshio, Y., Ma, W., Nakanishi, F., Piplani, N., Sakai, S., Sakuda, M., Tada, T., Tano, T., Xu, C., Yamaguchi, R., Ishizuka, T., Kuno, Y., Barr, G., Barrow, D., Cook, L., Samani, S., Simpson, C., Wark, D., Holin, A. M., Nova, F., Jung, S., Yang, B., Yang, J. Y., Yoo, J., Fannon, J. E. P., Kneale, L., Malek, M., McElwee, J. M., Stone, O., Thiesse, M. D., Thompson, L. F., Wilson, S. T., Okazawa, H., Lakshmi, S. M., Choi, Y., Kim, S. B., Kwon, E., Seo, J. W., Yu, I., Ichikawa, A. K., Tairahune, S., Nishijima, K., Eguchi, A., Iwamoto, K., Nakagiri, K., Nakajima, Y., Ogawa, N., Shima, S., Watanabe, E., Yokoyama, M., Calland, R. G., Fujita, S., Jesus-Valls, C., Junjie, X., Ming, T. K., de Perio, P., Martens, K., Murdoch, M., Vagins, M. R., Izumiyama, S., Kuze, M., Matsumoto, R., Okajima, Y., Tanaka, M., Yoshida, T., Inomoto, M., Ishitsuka, M., Ito, H., Kinoshita, T., Ohta, K., Ommura, Y., Shinoki, M., Shigeta, N., Suganuma, T., Yamaguchi, K., Martin, J. F., Nantais, C. M., Tanaka, H. A., Towstego, T., Gaur, R., Gousy-Leblanc, V., Hartz, M., Konaka, A., Li, X., Chen, S., Xu, B. D., Zhang, B., Berkman, S., Posiadala-Zezula, M., Boyd, S. B., Edwards, R., Hadley, D., Nicholson, M., O'Flaherty, M., Richards, B., Ali, A., Jamieson, B., Walker, J., Amanai, S., Marti, Ll., Minamino, A., Pintaudi, G., Sano, S., Sasaki, R., Suzuki, S., and Wada, K.
Subjects: High Energy Physics - Experiment
Abstract: An analysis of solar neutrino data from the fourth phase of Super-Kamiokande~(SK-IV) from October 2008 to May 2018 is performed and the results are presented. The observation time of the data set of SK-IV corresponds to $2970$~days and the total live time for all four phases is $5805$~days. For more precise solar neutrino measurements, several improvements are applied in this analysis: lowering the data acquisition threshold in May 2015, further reduction of the spallation background using neutron clustering events, precise energy reconstruction considering the time variation of the PMT gain. The observed number of solar neutrino events in $3.49$--$19.49$ MeV electron kinetic energy region during SK-IV is $65,443^{+390}_{-388}\,(\mathrm{stat.})\pm 925\,(\mathrm{syst.})$ events. Corresponding $\mathrm{^{8}B}$ solar neutrino flux is $(2.314 \pm 0.014\, \rm{(stat.)} \pm 0.040 \, \rm{(syst.)}) \times 10^{6}~\mathrm{cm^{-2}\,s^{-1}}$, assuming a pure electron-neutrino flavor component without neutrino oscillations. The flux combined with all SK phases up to SK-IV is $(2.336 \pm 0.011\, \rm{(stat.)} \pm 0.043 \, \rm{(syst.)}) \times 10^{6}~\mathrm{cm^{-2}\,s^{-1}}$. Based on the neutrino oscillation analysis from all solar experiments, including the SK $5805$~days data set, the best-fit neutrino oscillation parameters are $\rm{sin^{2} \theta_{12,\,solar}} = 0.306 \pm 0.013 $ and $\Delta m^{2}_{21,\,\mathrm{solar}} = (6.10^{+ 0.95}_{-0.81}) \times 10^{-5}~\rm{eV}^{2}$, with a deviation of about 1.5$\sigma$ from the $\Delta m^{2}_{21}$ parameter obtained by KamLAND. The best-fit neutrino oscillation parameters obtained from all solar experiments and KamLAND are $\sin^{2} \theta_{12,\,\mathrm{global}} = 0.307 \pm 0.012 $ and $\Delta m^{2}_{21,\,\mathrm{global}} = (7.50^{+ 0.19}_{-0.18}) \times 10^{-5}~\rm{eV}^{2}$., Comment: 47 pages, 61 figures
Published: 2023
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11. Atmospheric neutrino oscillation analysis with neutron tagging and an expanded fiducial volume in Super-Kamiokande I-V

Author: Collaboration, Super-Kamiokande, Wester, T., Abe, K., Bronner, C., Hayato, Y., Hiraide, K., Hosokawa, K., Ieki, K., Ikeda, M., Kameda, J., Kanemura, Y., Kaneshima, R., Kashiwagi, Y., Kataoka, Y., Miki, S., Mine, S., Miura, M., Moriyama, S., Nakano, Y., Nakahata, M., Nakayama, S., Noguchi, Y., Sato, K., Sekiya, H., Shiba, H., Shimizu, K., Shiozawa, M., Sonoda, Y., Suzuki, Y., Takeda, A., Takemoto, Y., Tanaka, H., Yano, T., Han, S., Kajita, T., Okumura, K., Tashiro, T., Tomiya, T., Wang, X., Yoshida, S., Fernandez, P., Labarga, L., Ospina, N., Zaldivar, B., Pointon, B. W., Kearns, E., Raaf, J. L., Wan, L., Bian, J., Griskevich, N. J., Locke, S., Smy, M. B., Sobel, H. W., Takhistov, V., Yankelevich, A., Hill, J., Lee, S. H., Moon, D. H., Park, R. G., Bodur, B., Scholberg, K., Walter, C. W., Beauchene, A., Drapier, O., Giampaolo, A., Mueller, Th. A., Santos, A. D., Paganini, P., Quilain, B., Nakamura, T., Jang, J. S., Machado, L. N., Learned, J. G., Choi, K., Iovine, N., Cao, S., Anthony, L. H. V., Martin, D., Prouse, N. W., Scott, M., Sztuc, A. A., Uchida, Y., Berardi, V., Catanesi, M. G., Radicioni, E., Calabria, N. F., Langella, A., De Rosa, G., Collazuol, G., Iacob, F., Mattiazzi, M., Ludovici, L., Gonin, M., Pronost, G., Fujisawa, C., Maekawa, Y., Nishimura, Y., Okazaki, R., Akutsu, R., Friend, M., Hasegawa, T., Ishida, T., Kobayashi, T., Jakkapu, M., Matsubara, T., Nakadaira, T., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Bhuiyan, N., Burton, G. T., Di Lodovico, F., Gao, J., Goldsack, A., Katori, T., Migenda, J., Ramsden, R., Xie, Z., Zsoldos, S., Suzuki, A. T., Takagi, Y., Takeuchi, Y., Zhong, H., Feng, J., Feng, L., Hu, J. R., Hu, Z., Kawaue, M., Kikawa, T., Mori, M., Nakaya, T., Wendell, R. A., Yasutome, K., Jenkins, S. J., McCauley, N., Mehta, P., Tarrant, A., Fukuda, Y., Itow, Y., Menjo, H., Ninomiya, K., Lagoda, J., Lakshmi, S. M., Mandal, M., Mijakowski, P., Prabhu, Y. S., Zalipska, J., Jia, M., Jiang, J., Jung, C. K., Shi, W., Wilking, M. J., Yanagisawa, C., Harada, M., Hino, Y., Ishino, H., Koshio, Y., Nakanishi, F., Sakai, S., Tada, T., Tano, T., Ishizuka, T., Barr, G., Barrow, D., Cook, L., Holin, A., Nova, F., Samani, S., Wark, D., Jung, S., Yang, B. S., Yang, J. Y., Yoo, J., Fannon, J. E. P., Kneale, L., Malek, M., McElwee, J. M., Thiesse, M. D., Thompson, L. F., Wilson, S. T., Okazawa, H., Kim, S. B., Kwon, E., Seo, J. W., Yu, I., Ichikawa, A. K., Nakamura, K. D., Tairafune, S., Nishijima, K., Koshiba, M., Eguchi, A., Nakagiri, K., Nakajima, Y., Shima, S., Taniuchi, N., Watanabe, E., Yokoyama, M., de Perio, P., Fujita, S., Martens, K., Tsui, K. M., Vagins, M. R., Xia, J., Izumiyama, S., Kuze, M., Matsumoto, R., Ishitsuka, M., Ito, H., Ommura, Y., Shigeta, N., Shinoki, M., Yamauchi, K., Yoshida, T., Gaur, R., Gousy-Leblanc, V., Hartz, M., Konaka, A., Li, X., Chen, S., Xu, B. D., Zhang, B., Posiadala-Zezula, M., Boyd, S. B., Edwards, R., Hadley, D., Nicholson, M., O'Flaherty, M., Richards, B., Ali, A., Jamieson, B., Amanai, S., Marti, Ll., Minamino, A., and Suzuki, S.
Subjects: High Energy Physics - Experiment
Abstract: We present a measurement of neutrino oscillation parameters with the Super-Kamiokande detector using atmospheric neutrinos from the complete pure-water SK I-V (April 1996-July 2020) data set, including events from an expanded fiducial volume. The data set corresponds to 6511.3 live days and an exposure of 484.2 kiloton-years. Measurements of the neutrino oscillation parameters $\Delta m^2_{32}$, $\sin^2\theta_{23}$, $\sin^2 \theta_{13}$, $\delta_{CP}$, and the preference for the neutrino mass ordering are presented with atmospheric neutrino data alone, and with constraints on $\sin^2 \theta_{13}$ from reactor neutrino experiments. Our analysis including constraints on $\sin^2 \theta_{13}$ favors the normal mass ordering at the 92.3% level., Comment: 24 pages, 18 figures
Published: 2023
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12. Measurement of the neutrino-oxygen neutral-current quasielastic cross section using atmospheric neutrinos in the SK-Gd experiment

Author: Sakai, S., Abe, K., Bronner, C., Hayato, Y., Hiraide, K., Hosokawa, K., Ieki, K., Ikeda, M., Kameda, J., Kanemura, Y., Kaneshima, R., Kashiwagi, Y., Kataoka, Y., Miki, S., Mine, S., Miura, M., Moriyama, S., Nakano, Y., Nakahata, M., Nakayama, S., Noguchi, Y., Sato, K., Sekiya, H., Shiba, H., Shimizu, K., Shiozawa, M., Sonoda, Y., Suzuki, Y., Takeda, A., Takemoto, Y., Tanaka, H., Yano, T., Han, S., Kajita, T., Okumura, K., Tashiro, T., Tomiya, T., Wang, X., Yoshida, S., Fernandez, P., Labarga, L., Ospina, N., Zaldivar, B., Pointon, B. W., Kearns, E., Raaf, J. L., Wan, L., Wester, T., Bian, J., Griskevich, N. J., Locke, S., Smy, M. B., Sobel, H. W., Takhistov, V., Yankelevich, A., Hill, J., Jang, M. C., Lee, S. H., Moon, D. H., Park, R. G., Bodur, B., Scholberg, K., Walter, C. W., Beauchene, A., Drapier, O., Giampaolo, A., Mueller, Th. A., Santos, A. D., Paganini, P., Quilain, B., Nakamura, T., Jang, J. S., Machado, L. N., Learned, J. G., Choi, K., Iovine, N., Cao, S., Anthony, L. H. V., Martin, D., Prouse, N. W., Scott, M., Sztuc, A. A., Uchida, Y., Berardi, V., Calabria, N. F., Catanesi, M. G., Radicioni, E., Langella, A., De Rosa, G., Collazuol, G., Iacob, F., Mattiazzi, M., Ludovici, L., Gonin, M., Pronost, G., Fujisawa, C., Maekawa, Y., Nishimura, Y., Okazaki, R., Akutsu, R., Friend, M., Hasegawa, T., Ishida, T., Kobayashi, T., Jakkapu, M., Matsubara, T., Nakadaira, T., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Bhuiyan, N., Burton, G. T., Di Lodovico, F., Gao, J., Goldsack, A., Katori, T., Migenda, J., Ramsden, R. M., Xie, Z., Zsoldos, S., Suzuki, A. T., Takagi, Y., Zhong, H., Takeuchi, Y., Feng, J., Feng, L., Hu, J. R., Hu, Z., Kawaue, M., Kikawa, T., Mori, M., Nakaya, T., Wendell, R. A., Yasutome, K., Jenkins, S. J., McCauley, N., Mehta, P., Tarant, A., Fukuda, Y., Itow, Y., Menjo, H., Ninomiya, K., Yoshioka, Y., Lagoda, J., Lakshmi, S. M., Mandal, M., Mijakowski, P., Prabhu, Y. S., Zalipska, J., Jia, M., Jiang, J., Jung, C. K., Shi, W., Wilking, M. J., Yanagisawa, C., Harada, M., Hino, Y., Ishino, H., Koshio, Y., Nakanishi, F., Tada, T., Tano, T., Ishizuka, T., Barr, G., Barrow, D., Cook, L., Samani, S., Wark, D., Holin, A., Nova, F., Jung, S., Yang, B. S., Yang, J. Y., Yoo, J., Fannon, J. E. P., Kneale, L., Malek, M., McElwee, J. M., Thiesse, M. D., Thompson, L. F., Wilson, S. T., Okazawa, H., Kim, S. B., Kwon, E., Seo, J. W., Yu, I., Ichikawa, A. K., Nakamura, K. D., Tairafune, S., Nishijima, K., Eguchi, A., Nakagiri, K., Nakajima, Y., Shima, S., Taniuchi, N., Watanabe, E., Yokoyama, M., de Perio, P., Fujita, S., Martens, K., Tsui, K. M., Vagins, M. R., Xia, J., Izumiyama, S., Kuze, M., Matsumoto, R., Ishitsuka, M., Ito, H., Ommura, Y., Shigeta, N., Shinoki, M., Yamauchi, K., Yoshida, T., Gaur, R., Gousy-Leblanc, V., Hartz, M., Konaka, A., Li, X., Chen, S., Xu, B. D., Zhang, B., Posiadala-Zezula, M., Boyd, S. B., Edwards, R., Hadley, D., Nicholson, M., O'Flaherty, M., Richards, B., Ali, A., Jamieson, B., Amanai, S., Marti, Ll., Minamino, A., and Suzuki, S.
Subjects: High Energy Physics - Experiment
Abstract: We report the first measurement of the atmospheric neutrino-oxygen neutral-current quasielastic (NCQE) cross section in the gadolinium-loaded Super-Kamiokande (SK) water Cherenkov detector. In June 2020, SK began a new experimental phase, named SK-Gd, by loading 0.011% by mass of gadolinium into the ultrapure water of the SK detector. The introduction of gadolinium to ultrapure water has the effect of improving the neutron-tagging efficiency. Using a 552.2 day data set from August 2020 to June 2022, we measure the NCQE cross section to be 0.74 $\pm$ 0.22(stat.) $^{+0.85}_{-0.15}$ (syst.) $\times$ 10$^{-38}$ cm$^{2}$/oxygen in the energy range from 160 MeV to 10 GeV, which is consistent with the atmospheric neutrino-flux-averaged theoretical NCQE cross section and the measurement in the SK pure-water phase within the uncertainties. Furthermore, we compare the models of the nucleon-nucleus interactions in water and find that the Binary Cascade model and the Liege Intranuclear Cascade model provide a somewhat better fit to the observed data than the Bertini Cascade model. Since the atmospheric neutrino-oxygen NCQE reactions are one of the main backgrounds in the search for diffuse supernova neutrino background (DSNB), these new results will contribute to future studies - and the potential discovery - of the DSNB in SK., Comment: 8 pages, 3 figures
Published: 2023

13. Search for Periodic Time Variations of the Solar $^8$B Neutrino Flux between 1996 and 2018 in Super-Kamiokande

Author: Abe, K., Bronner, C., Hayato, Y., Hiraide, K., Hosokawa, K., Ieki, K., Ikeda, M., Kameda, J., Kanemura, Y., Kaneshima, R., Kashiwagi, Y., Kataoka, Y., Miki, S., Mine, S., Miura, M., Moriyama, S., Nakano, Y., Nakahata, M., Nakayama, S., Noguchi, Y., Sato, K., Sekiya, H., Shiba, H., Shimizu, K., Shiozawa, M., Sonoda, Y., Suzuki, Y., Takeda, A., Takemoto, Y., Tanaka, H., Yano, T., Han, S., Kajita, T., Okumura, K., Tashiro, T., Tomiya, T., Wang, X., Yoshida, S., Fernandez, P., Labarga, L., Ospina, N., Zaldivar, B., Pointon, B. W., Kearns, E., Raaf, J. L., Wan, L., Wester, T., Bian, J., Griskevich, N. J., Locke, S., Smy, M. B., Sobel, H. W., Takhistov, V., Yankelevich, A., Hill, J., Lee, S. H., Moon, D. H., Park, R. G., Jang, M. C., Bodur, B., Scholberg, K., Walter, C. W., Beauchene, A., Drapier, O., Giampaolo, A., Mueller, Th. A., Santos, A. D., Paganini, P., Quilain, B., Nakamura, T., Jang, J. S., Machado, L. N., Learned, J. G., Choi, K., Iovine, N., Cao, S., Anthony, L. H. V., Martin, D., Prouse, N. W., Scott, M., Sztuc, A. A., Uchida, Y., Berardi, V., Catanesi, M. G., Radicioni, E., Calabria, N. F., Langella, A., De Rosa, G., Collazuol, G., Iacob, F., Mattiazzi, M., Ludovici, L., Gonin, M., Pronost, G., Fujisawa, C., Maekawa, Y., Nishimura, Y., Okazaki, R., Akutsu, R., Friend, M., Hasegawa, T., Ishida, T., Kobayashi, T., Jakkapu, M., Matsubara, T., Nakadaira, T., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Bhuiyan, N., Burton, G. T., Di Lodovico, F., Gao, J., Goldsack, A., Katori, T., Migenda, J., Xie, Z., Ramsden, R. M., Zsoldos, S., Suzuki, A. T., Takagi, Y., Zhong, H., Takeuchi, Y., Feng, J., Feng, L., Hu, J. R., Hu, Z., Kikawa, T., Mori, M., Kawaue, M., Nakaya, T., Wendell, R. A., Yasutome, K., Jenkins, S. J., McCauley, N., Mehta, P., Tarant, A., Fukuda, Y., Itow, Y., Menjo, H., Ninomiya, K., Yoshioka, Y., Lagoda, J., Lakshmi, S. M., Mandal, M., Mijakowski, P., Prabhu, Y. S., Zalipska, J., Jia, M., Jiang, J., Jung, C. K., Wilking, M. J., Yanagisawa, C., Shi, W., Harada, M., Hino, Y., Ishino, H., Koshio, Y., Nakanishi, F., Sakai, S., Tada, T., Tano, T., Ishizuka, T., Barr, G., Barrow, D., Cook, L., Samani, S., Wark, D., Holin, A., Nova, F., Yang, B. S., Yang, J. Y., Yoo, J., Jung, S., Fannon, J. E. P., Kneale, L., Malek, M., McElwee, J. M., Thiesse, M. D., Thompson, L. F., Wilson, S. T., Okazawa, H., Kim, S. B., Kwon, E., Seo, J. W., Yu, I., Ichikawa, A. K., Nakamura, K. D., Tairafune, S., Nishijima, K., Eguchi, A., Nakagiri, K., Nakajima, Y., Shima, S., Taniuchi, N., Watanabe, E., Yokoyama, M., de Perio, P., Fujita, S., Martens, K., Tsui, K. M., Vagins, M. R., Xia, J., Izumiyama, S., Kuze, M., Matsumoto, R., Ishitsuka, M., Ito, H., Ommura, Y., Shigeta, N., Shinoki, M., Yamauchi, K., Yoshida, T., Gaur, R., Gousy-Leblanc, V., Hartz, M., Konaka, A., Li, X., Chen, S., Xu, B. D., Zhang, B., Posiadala-Zezula, M., Boyd, S. B., Edwards, R., Hadley, D., Nicholson, M., Flaherty, M. O, Richards, B., Ali, A., Jamieson, B., Amanai, S., Marti, Ll., Minamino, A., and Suzuki, S.
Subjects: High Energy Physics - Experiment
Abstract: We report a search for time variations of the solar $^8$B neutrino flux using 5804 live days of Super-Kamiokande data collected between May 31, 1996, and May 30, 2018. Super-Kamiokande measured the precise time of each solar neutrino interaction over 22 calendar years to search for solar neutrino flux modulations with unprecedented precision. Periodic modulations are searched for in a dataset comprising five-day interval solar neutrino flux measurements with a maximum likelihood method. We also applied the Lomb-Scargle method to this dataset to compare it with previous reports. The only significant modulation found is due to the elliptic orbit of the Earth around the Sun. The observed modulation is consistent with astronomical data: we measured an eccentricity of (1.53$\pm$0.35)\%, and a perihelion shift of ($-$1.5$\pm$13.5) days., Comment: 8 pages, 5 figures, 2 tables, and data file: "sksolartimevariation5804d.txt" (the data file updated with additional 3 columns -- R^2 correction, upper-error, lower-error)
Published: 2023

14. The acrylic vessel for JSNS$^{2}$-II neutrino target

Author: Shin, C. D., Ajimura, S., Cheoun, M. K., Choi, J. H., Choi, J. Y., Dodo, T., Goh, J., Haga, K., Harada, M., Hasegawa, S., Hiraiwa, T., Hwang, W., Iida, T., Jang, H. I., Jang, J. S., Jeon, H., Jeon, S., Joo, K. K., Jung, D. E., Kang, S. K., Kasugai, Y., Kawasaki, T., Kim, E. J., Kim, J. Y., Kim, S. B., Kim, W., Kinoshita, H., Konno, T., Lee, D. H., Lim, I. T., Little, C., Marzec, E., Maruyama, T., Masuda, S., Meigo, S., Monjushiro, S., Moon, D. H., Nakano, T., Niiyama, M., Nishikawa, K., Pac, M. Y., Park, H. W., Park, J. S., Park, R. G., Peeters, S. J. M., Rott, C., Sakai, K., Sakamoto, S., Shima, T., Spitz, J., Suekane, F., Sugaya, Y., Suzuya, K., Taira, M., Takeuchi, Y., Yamaguchi, Y., Yeh, M., Yeo, I. S., Yoo, C., and Yu, I.
Subjects: High Energy Physics - Experiment, Physics - Instrumentation and Detectors
Abstract: The JSNS$^{2}$ (J-PARC Sterile Neutrino Search at J-PARC Spallation Neutron Source) is an experiment designed for the search for sterile neutrinos. The experiment is currently at the stage of the second phase named JSNS$^{2}$-II with two detectors at near and far locations from the neutrino source. One of the key components of the experiment is an acrylic vessel, that is used for the target volume for the detection of the anti-neutrinos. The specifications, design, and measured properties of the acrylic vessel are described.
Published: 2023
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15. Study on the accidental background of the JSNS$^2$ experiment

Author: Lee, D. H., Ajimura, S., Cheoun, M. K., Choi, J. H., Choi, J. Y., Dodo, T., Goh, J., Haga, K., Harada, M., Hasegawa, S., Hiraiwa, T., Hwang, W., Jang, H. I., Jang, J. S., Jeon, H., Jeon, S., Joo, K. K., Jung, D. E., Kang, S. K., Kasugai, Y., Kawasaki, T., Kim, E. J., Kim, J. Y., Kim, S. B., Kim, W., Kinoshita, H., Konno, T., Lim, I. T., Little, C., Marzec, E., Maruyama, T., Masuda, S., Meigom, S., Monjushiro, S., Moon, D. H., Nakano, T., Niiyama, M., Nishikawa, K., Pac, M. Y., Park, H. W., Park, J. S., Park, R. G., Peeters, S. J. M., Rott, C., Sakai, K., Sakamoto, S., Shima, T., Shin, C. D., Spitz, J., Suekane, F., Sugaya, Y., Suzuya, K., Taira, M., Yamaguchi, Y., Yeh, M., Yeo, I. S., Yoo, C., and Yu, I.
Subjects: High Energy Physics - Experiment, Physics - Instrumentation and Detectors
Abstract: JSNS$^2$ (J-PARC Sterile Neutrino Search at J-PARC Spallation Neutron Source) is an experiment which searches for sterile neutrinos via the observation of $\bar{\nu}_{\mu} \to \bar{\nu}_{e}$ appearance oscillations using muon decay-at-rest neutrinos. The data taking of JSNS$^2$ have been performed from 2021. In this manuscript, a study of the accidental background is presented. The rate of the accidental background is (9.29$\pm 0.39) \times 10^{-8}$ / spill with 0.75 MW beam power and comparable to the number of searching signals., Comment: arXiv admin note: substantial text overlap with arXiv:2111.07482
Published: 2023
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16. Search for astrophysical electron antineutrinos in Super-Kamiokande with 0.01wt% gadolinium-loaded water

Author: Harada, M., Abe, K., Bronner, C., Hayato, Y., Hiraide, K., Hosokawa, K., Ieki, K., Ikeda, M., Kameda, J., Kanemura, Y., Kaneshima, R., Kashiwagi, Y., Kataoka, Y., Miki, S., Mine, S., Miura, M., Moriyama, S., Nakano, Y., Nakahata, M., Nakayama, S., Noguchi, Y., Okamoto, K., Sato, K., Sekiya, H., Shiba, H., Shimizu, K., Shiozawa, M., Sonoda, Y., Suzuki, Y., Takeda, A., Takemoto, Y., Takenaka, A., Tanaka, H., Watanabe, S., Yano, T., Han, S., Kajita, T., Okumura, K., Tashiro, T., Tomiya, T., Wang, X., Yoshida, S., Megias, G. D., Fernandez, P., Labarga, L., Ospina, N., Zaldivar, B., Pointon, B. W., Kearns, E., Raaf, J. L., Wan, L., Wester, T., Bian, J., Griskevich, N. J., Locke, S., Smy, M. B., Sobel, H. W., Takhistov, V., Yankelevich, A., Hill, J., Lee, S. H., Moon, D. H., Park, R. G., Bodur, B., Scholberg, K., Walter, C. W., Beauchene, A., Drapier, O., Giampaolo, A., Mueller, Th. A., Santos, A. D., Paganini, P., Quilain, B., Ishizuka, T., Nakamura, T., Jang, J. S., Learned, J. G., Choi, K., Iovine, N., Cao, S., Anthony, L. H. V., Martin, D., Scott, M., Sztuc, A. A., Uchida, Y., Berardi, V., Catanesi, M. G., Radicioni, E., Calabria, N. F., Langella, A., Machado, L. N., De Rosa, G., Collazuol, G., Iacob, F., Lamoureux, M., Mattiazzi, M., Ludovici, L., Gonin, M., Pronost, G., Fujisawa, C., Maekawa, Y., Nishimura, Y., Okazaki, R., Akutsu, R., Friend, M., Hasegawa, T., Ishida, T., Kobayashi, T., Jakkapu, M., Matsubara, T., Nakadaira, T., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Bhuiyan, N., Burton, G. T., Di Lodovico, F., Gao, J., Goldsack, A., Katori, T., Migenda, J., Xie, Z., Zsoldos, S., Kotsar, Y., Ozaki, H., Suzuki, A. T., Takagi, Y., Takeuchi, Y., Feng, J., Feng, L., Hu, J. R., Hu, Z., Kikawa, T., Mori, M., Nakaya, T., Wendell, R. A., Yasutome, K., Jenkins, S. J., McCauley, N., Mehta, P., Tarrant, A., Fukuda, Y., Itow, Y., Menjo, H., Ninomiya, K., Lagoda, J., Lakshmi, S. M., Mandal, M., Mijakowski, P., Prabhu, Y. S., Zalipska, J., Jia, M., Jiang, J., Jung, C. K., Wilking, M. J., Yanagisawa, C., Hino, Y., Ishino, H., Kitagawa, H., Koshio, Y., Nakanishi, F., Sakai, S., Tada, T., Tano, T., Barr, G., Barrow, D., Cook, L., Samani, S., Wark, D., Holin, A., Nova, F., Yang, B. S., Yang, J. Y., Yoo, J., Fannon, J. E. P., Kneale, L., Malek, M., McElwee, J. M., Thiesse, M. D., Thompson, L. F., Wilson, S. T., Okazawa, H., Kim, S. B., Kwon, E., Seo, J. W., Yu, I., Ichikawa, A. K., Nakamura, K. D., Tairafune, S., Nishijima, K., Nakagiri, K., Nakajima, Y., Shima, S., Taniuchi, N., Watanabe, E., Yokoyama, M., de Perio, P., Martens, K., Tsui, K. M., Vagins, M. R., Xia, J., Kuze, M., Izumiyama, S., Matsumoto, R., Ishitsuka, M., Ito, H., Kinoshita, T., Ommura, Y., Shigeta, N., Shinoki, M., Suganuma, T., Yamauchi, K., Martin, J. F., Tanaka, H. A., Towstego, T., Gaur, R., Gousy-Leblanc, V., Hartz, M., Konaka, A., Li, X., Prouse, N. W., Chen, S., Xu, B. D., Zhang, B., Posiadala-Zezula, M., Boyd, S. B., Edwards, R., Hadley, D., Nicholson, M., Flaherty, M. O, Richards, B., Ali, A., Jamieson, B., Marti, Ll., Minamino, A., Pintaudi, G., Sano, S., Suzuki, S., and Wada, K.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, High Energy Physics - Experiment, Nuclear Experiment, Physics - Instrumentation and Detectors
Abstract: We report the first search result for the flux of astrophysical electron antineutrinos for energies O(10) MeV in the gadolinium-loaded Super-Kamiokande (SK) detector. In June 2020, gadolinium was introduced to the ultra-pure water of the SK detector in order to detect neutrons more efficiently. In this new experimental phase, SK-Gd, we can search for electron antineutrinos via inverse beta decay with efficient background rejection and higher signal efficiency thanks to the high efficiency of the neutron tagging technique. In this paper, we report the result for the initial stage of SK-Gd with a $22.5\times552$ $\rm kton\cdot day$ exposure at 0.01% Gd mass concentration. No significant excess over the expected background in the observed events is found for the neutrino energies below 31.3 MeV. Thus, the flux upper limits are placed at the 90% confidence level. The limits and sensitivities are already comparable with the previous SK result with pure-water ($22.5 \times 2970 \rm kton\cdot day$) owing to the enhanced neutron tagging.
Published: 2023
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17. Measurement of the cosmogenic neutron yield in Super-Kamiokande with gadolinium loaded water

Author: Collaboration, Super-Kamiokande, Shinoki, M., Abe, K., Hayato, Y., Hiraide, K., Hosokawa, K., Ieki, K., Ikeda, M., Kameda, J., Kanemura, Y., Kaneshima, R., Kashiwagi, Y., Kataoka, Y., Miki, S., Mine, S., Miura, M., Moriyama, S., Nakano, Y., Nakahata, M., Nakayama, S., Noguchi, Y., Okamoto, K., Sato, K., Sekiya, H., Shiba, H., Shimizu, K., Shiozawa, M., Sonoda, Y., Suzuki, Y., Takeda, A., Takemoto, Y., Takenaka, A., Tanaka, H., Watanabe, S., Yano, T., Han, S., Kajita, T., Okumura, K., Tashiro, T., Tomiya, T., Wang, X., Yoshida, S., Megias, G. D., Fernandez, P., Labarga, L., Ospina, N., Zaldivar, B., Pointon, B. W., Kearns, E., Raaf, J. L., Wan, L., Wester, T., Bian, J., Griskevich, N. J., Kropp, W. R., Locke, S., Smy, M. B., Sobel, H. W., Takhistov, V., Yankelevich, A., Hill, J., Lee, S. H., Moon, D. H., Park, R. G., Bodur, B., Scholberg, K., Walter, C. W., Beauchêne, A., Bernard, L., Coffani, A., Drapier, O., Hedri, S. El, Giampaolo, A., Mueller, Th. A., Santos, A. D., Paganini, P., Quilain, B., Ishizuka, T., Nakamura, T., Jang, J. S., Learned, J. G., Choi, K., Cao, S., Anthony, L. H. V., Martin, D., Scott, M., Sztuc, A. A., Uchida, Y., Berardi, V., Catanesi, M. G., Radicioni, E., Calabria, N. F., Langella, A., Machado, L. N., De Rosa, G., Collazuol, G., Iacob, F., Lamoureux, M., Mattiazzi, M., Ludovici, L., Gonin, M., Pronost, G., Fujisawa, C., Maekawa, Y., Nishimura, Y., Akutsu, R., Friend, M., Hasegawa, T., Ishida, T., Kobayashi, T., Jakkapu, M., Matsubara, T., Nakadaira, T., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Bhuiyan, N., Boschi, T., Burton, G. T., Di Lodovico, F., Gao, J., Goldsack, A., Katori, T., Migenda, J., Taani, M., Xie, Z., Zsoldos, S., Kotsar, Y., Ozaki, H., Suzuki, A. T., Takeuchi, Y., Bronner, C., Feng, J., Kikawa, T., Mori, M., Nakaya, T., Wendell, R. A., Yasutome, K., Jenkins, S. J., McCauley, N., Mehta, P., Tarrant, A., Tsui, K. M., Fukuda, Y., Itow, Y., Menjo, H., Ninomiya, K., Lagoda, J., Lakshmi, S. M., Mandal, M., Mijakowski, P., Prabhu, Y. S., Zalipska, J., Jia, M., Jiang, J., Jung, C. K., Wilking, M. J., Yanagisawa, C., Harada, M., Ishino, H., Ito, S., Kitagawa, H., Koshio, Y., Nakanishi, F., Sakai, S., Barr, G., Barrow, D., Cook, L., Samani, S., Wark, D., Holin, A., Nova, F., Yang, J. Y., Yang, B. S., Yoo, J., Fannon, J. E. P., Kneale, L., Malek, M., McElwee, J. M., Stone, O., Thiesse, M. D., Thompson, L. F., Okazawa, H., Kim, S. B., Kwon, E., Seo, J. W., Yu, I., Ichikawa, A. K., Nakamura, K. D., Tairafune, S., Nishijima, K., Koshiba, M., Iwamoto, K., Nakagiri, K., Nakajima, Y., Shima, S., Taniuchi, N., Yokoyama, M., Martens, K., de Perio, P., Vagins, M. R., Xia, J., Kuze, M., Izumiyama, S., Inomoto, M., Ishitsuka, M., Ito, H., Kinoshita, T., Matsumoto, R., Ommura, Y., Shigeta, N., Suganuma, T., Yamauchi, K., Martin, J. F., Tanaka, H. A., Towstego, T., Gaur, R., Gousy-Leblanc, V., Hartz, M., Konaka, A., Li, X., Prouse, N. W., Chen, S., Xu, B. D., Zhang, B., Posiadala-Zezula, M., Boyd, S. B., Hadley, D., Nicholson, M., O'Flaherty, M., Richards, B., Ali, A., Jamieson, B., Marti, Ll., Minamino, A., Pintaudi, G., Sano, S., Suzuki, S., and Wada, K.
Subjects: High Energy Physics - Experiment
Abstract: Cosmic-ray muons that enter the Super-Kamiokande detector cause hadronic showers due to spallation in water, producing neutrons and radioactive isotopes. Those are a major background source for studies of MeV-scale neutrinos and searches for rare events. Since 2020, gadolinium was introduced in the ultra-pure water in the Super-Kamiokande detector to improve the detection efficiency of neutrons. In this study, the cosmogenic neutron yield was measured using data acquired during the period after the gadolinium loading. The yield was found to be $(2.76 \pm 0.02\,\mathrm{(stat.) \pm 0.19\,\mathrm{(syst.)}}) \times 10^{-4}\,\mu^{-1} \mathrm{g^{-1} cm^{2}}$ at 259 GeV of average muon energy at the Super-Kamiokande detector., Comment: 10 pages, 10 figures, 3 tables
Published: 2022

18. Searching for neutrinos from solar flares across solar cycles 23 and 24 with the Super-Kamiokande detector

Author: Okamoto, K., Abe, K., Hayato, Y., Hiraide, K., Hosokawa, K., Ieki, K., Ikeda, M., Kameda, J., Kanemura, Y., Kaneshima, Y., Kataoka, Y., Kashiwagi, Y., Miki, S., Mine, S., Miura, M., Moriyama, S., Nagao, Y., Nakahata, M., Nakano, Y., Nakayama, S., Noguchi, Y., Sato, K., Sekiya, H., Shimizu, K., Shiozawa, M., Shiba, H., Sonoda, Y., Suzuki, Y., Takeda, A., Takemoto, Y., Takenaka, A., Tanaka, H., Watanabe, S., Yano, T., Han, S., Kajita, T., Okumura, K., Tashiro, T., Tomiya, T., Wang, X., Xia, J., Yoshida, S., Megias, G. D., Fernandez, P., Labarga, L., Ospina, N., Zaldivar, B., Pointon, B. W., Kearns, E., Raaf, J. L., Wan, L., Wester, T., Bian, J., Griskevich, N. J., Kropp, W. R., Locke, S., Smy, M. B., Sobel, H. W., Takhistov, V., Yankelevich, A., Hill, J., Kim, J. Y., Lee, S. H., Lim, I. T., Moon, D. H., Park, R. G., Bodur, B., Scholberg, K., Walter, C. W., Beauchene, A., Bernard, L., Coffani, A., Drapier, O., Hedri, S. El, Giampaolo, A., Mueller, Th. A., Santos, A. D., Paganini, P., Quilain, B., Ishizuka, T., Nakamura, T., Jang, J. S., Learned, J. G., Choi, K., Cao, S., Anthony, L. H. V., Martin, D., Scott, M., Sztuc, A. A., Uchida, Y., Berardi, V., Catanesi, M. G., Radicioni, E., Calabria, N. F., Machado, L. N., De Rosa, G., Collazuol, G., Iacob, F., Lamoureux, M., Mattiazzi, M., Ludovici, L., Gonin, M., Pronost, G., Fujisawa, C., Maekawa, Y., Nishimura, Y., Friend, M., Hasegawa, T., Ishida, T., Kobayashi, T., Jakkapu, M., Matsubara, T., Nakadaira, T., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Bhuiyan, N., Boschi, T., Burton, G. T., Di Lodovico, F., Gao, J., Goldsack, A., Katori, T., Migenda, J., Taani, M., Xie, Z., Zsoldos, S., Kotsar, Y., Ozaki, H., Suzuki, A. T., Takeuchi, Y., Yamamoto, S., Bronner, C., Feng, J., Kikawa, T., Mori, M., Nakaya, T., Wendell, R. A., Yasutome, K., Jenkins, S. J., McCauley, N., Mehta, P., Tarrant, A., Tsui, K. M., Fukuda, Y., Itow, Y., Menjo, H., Ninomiya, K., Lagoda, J., Lakshmi, S. M., Mandal, M., Mijakowski, P., Prabhu, Y. S., Zalipska, J., Jia, M., Jiang, J., Jung, C. K., Vilela, C., Wilking, M. J., Yanagisawa, C., Harada, M., Ishino, H., Ito, S., Kitagawa, H., Koshio, Y., Ma, W., Nakanishi, F., Piplani, N., Sakai, S., Barr, G., Barrow, D., Cook, L., Samani, S., Wark, D., Holin, A., Nova, F., Yang, J. Y., Fannon, J. E. P., Malek, M., McElwee, J. M., Stone, O., Thiesse, M. D., Thompson, L. F., Okazawa, H., Kim, S. B., Kwon, E., Seo, J. W., Yu, I., Ichikawa, A. K., Nakamura, K. D., Tairafune, S., Nishijima, K., Koshiba, M., Iwamoto, K., Nakagiri, K., Nakajima, Y., Shima, S., Taniuchi, N., Yokoyama, M., Martens, K., de Perio, P., Vagins, M. R., Kuze, M., Izumiyama, S., Inomoto, M., Ishitsuka, M., Ito, H., Kinoshita, T., Matsumoto, R., Ommura, Y., Shigeta, N., Shinoki, M., Suganuma, T., Yamauchi, K., Martin, J. F., Tanaka, H. A., Towstego, T., Akutsu, R., Gaur, R., Gousy-Leblanc, V., Hartz, M., Konaka, A., Li, X., Prouse, N. W., Chen, S., Xu, B. D., Zhang, B., Posiadala-Zezula, M., Boyd, S. B., Hadley, D., Nicholson, M., O'Flaherty, M., Richards, B., Ali, A., Jamieson, B., Walker, J., Marti, Ll., Minamino, A., Pintaudi, G., Sano, S., Sasaki, R., Suzuki, S., and Wada, K.
Subjects: Astrophysics - Solar and Stellar Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, High Energy Physics - Experiment, Physics - Space Physics
Abstract: Neutrinos associated with solar flares (solar-flare neutrinos) provide information on particle acceleration mechanisms during the impulsive phase of solar flares. We searched using the Super-Kamiokande detector for neutrinos from solar flares that occurred during solar cycles $23$ and $24$, including the largest solar flare (X28.0) on November 4th, 2003. In order to minimize the background rate we searched for neutrino interactions within narrow time windows coincident with $\gamma$-rays and soft X-rays recorded by satellites. In addition, we performed the first attempt to search for solar-flare neutrinos from solar flares on the invisible side of the Sun by using the emission time of coronal mass ejections (CMEs). By selecting twenty powerful solar flares above X5.0 on the visible side and eight CMEs whose emission speed exceeds $2000$ $\mathrm{km \, s^{-1}}$ on the invisible side from 1996 to 2018, we found two (six) neutrino events coincident with solar flares occurring on the visible (invisible) side of the Sun, with a typical background rate of $0.10$ ($0.62$) events per flare in the MeV-GeV energy range. No significant solar-flare neutrino signal above the estimated background rate was observed. As a result we set the following upper limit on neutrino fluence at the Earth $\mathit{\Phi}<1.1\times10^{6}$ $\mathrm{cm^{-2}}$ at the $90\%$ confidence level for the largest solar flare. The resulting fluence limits allow us to constrain some of the theoretical models for solar-flare neutrino emission., Comment: 36 pages, 18 figures, 9 tables (Figure 12 was replaced because it was incorrect in version 1.)
Published: 2022

19. Search for Cosmic-ray Boosted Sub-GeV Dark Matter using Recoil Protons at Super-Kamiokande

Author: Collaboration, The Super-Kamiokande, Abe, K., Hayato, Y., Hiraide, K., Ieki, K., Ikeda, M., Kameda, J., Kanemura, Y., Kaneshima, R., Kashiwagi, Y., Kataoka, Y., Miki, S., Mine, S., Miura, M., Moriyama, S., Nakano, Y., Nakahata, M., Nakayama, S., Noguchi, Y., Okamoto, K., Sato, K., Sekiya, H., Shiba, H., Shimizu, K., Shiozawa, M., Sonoda, Y., Suzuki, Y., Takeda, A., Takemoto, Y., Takenaka, A., Tanaka, H., Watanabe, S., Yano, T., Han, S., Kajita, T., Okumura, K., Tashiro, T., Tomiya, T., Wang, X., Xia, J., Yoshida, S., Megias, G. D., Fernandez, P., Labarga, L., Ospina, N., Zaldivar, B., Pointon, B. W., Kearns, E., Raaf, J. L., Wan, L., Wester, T., Bian, J., Griskevich, N. J., Kropp, W. R., Locke, S., Smy, M. B., Sobel, H. W., Takhistov, V., Yankelevich, A., Hill, J., Park, R. G., Bodur, B., Scholberg, K., Walter, C. W., Bernard, L., Coffani, A., Drapier, O., Hedri, S. El, Giampaolo, A., Mueller, Th. A., Santos, A. D., Paganini, P., Quilain, B., Ishizuka, T., Nakamura, T., Jang, J. S., Learned, J. G., Choi, K., Cao, S., Anthony, L. H. V., Martin, D., Scott, M., Sztuc, A. A., Uchida, Y., Berardi, V., Catanesi, M. G., Radicioni, E., Calabria, N. F., Machado, L. N., De Rosa, G., Collazuol, G., Iacob, F., Lamoureux, M., Mattiazzi, M., Ludovici, L., Gonin, M., Pronost, G., Fujisawa, C., Maekawa, Y., Nishimura, Y., Friend, M., Hasegawa, T., Ishida, T., Kobayashi, T., Jakkapu, M., Matsubara, T., Nakadaira, T., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Boschi, T., Di Lodovico, F., Gao, J., Goldsack, A., Katori, T., Migenda, J., Taani, M., Zsoldos, S., Kotsar, Y., Ozaki, H., Suzuki, A. T., Takeuchi, Y., Bronner, C., Feng, J., Kikawa, T., Mori, M., Nakaya, T., Wendell, R. A., Yasutome, K., Jenkins, S. J., McCauley, N., Mehta, P., Tsui, K. M., Fukuda, Y., Itow, Y., Menjo, H., Ninomiya, K., Lagoda, J., Lakshmi, S. M., Mandal, M., Mijakowski, P., Prabhu, Y. S., Zalipska, J., Jia, M., Jiang, J., Jung, C. K., Wilking, M. J., Yanagisawa, C., Harada, M., Ishino, H., Ito, S., Kitagawa, H., Koshio, Y., Nakanishi, F., Sakai, S., Barr, G., Barrow, D., Cook, L., Samani, S., Wark, D., Nova, F., Yang, J. Y., Malek, M., McElwee, J. M., Stone, O., Thiesse, M. D., Thompson, L. F., Okazawa, H., Kim, S. B., Seo, J. W., Yu, I., Ichikawa, A. K., Nakamura, K. D., Tairafune, S., Nishijima, K., Iwamoto, K., Nakagiri, K., Nakajima, Y., Taniuchi, N., Yokoyama, M., Martens, K., de Perio, P., Vagins, M. R., Kuze, M., Izumiyama, S., Inomoto, M., Ishitsuka, M., Ito, H., Kinoshita, T., Matsumoto, R., Ommura, Y., Shigeta, N., Shinoki, M., Suganuma, T., Yamauchi, K., Martin, J. F., Tanaka, H. A., Towstego, T., Akutsu, R., Gousy-Leblanc, V., Hartz, M., Konaka, A., Prouse, N. W., Chen, S., Xu, B. D., Zhang, B., Posiadala-Zezula, M., Hadley, D., Nicholson, M., O'Flaherty, M., Richards, B., Ali, A., Jamieson, B., Marti, Ll., Minamino, A., Pintaudi, G., Sano, S., Suzuki, S., and Wada, K.
Subjects: High Energy Physics - Experiment
Abstract: We report a search for cosmic-ray boosted dark matter with protons using the 0.37 megaton$\times$years data collected at Super-Kamiokande experiment during the 1996-2018 period (SKI-IV phase). We searched for an excess of proton recoils above the atmospheric neutrino background from the vicinity of the Galactic Center. No such excess is observed, and limits are calculated for two reference models of dark matter with either a constant interaction cross-section or through a scalar mediator. This is the first experimental search for boosted dark matter with hadrons using directional information. The results present the most stringent limits on cosmic-ray boosted dark matter and exclude the dark matter-nucleon elastic scattering cross-section between $10^{-33}\text{ cm}^{2}$ and $10^{-27}\text{ cm}^{2}$ for dark matter mass from 10 MeV/$c^2$ to 1 GeV/$c^2$., Comment: With 1-page appendix. A bug was found in July 2023. This version is updated to match the erratum
Published: 2022
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20. Neutron Tagging following Atmospheric Neutrino Events in a Water Cherenkov Detector

Author: Abe, K., Haga, Y., Hayato, Y., Hiraide, K., Ieki, K., Ikeda, M., Imaizumi, S., Iyogi, K., Kameda, J., Kanemura, Y., Kataoka, Y., Kato, Y., Kishimoto, Y., Miki, S., Mine, S., Miura, M., Mochizuki, T., Moriyama, S., Nagao, Y., Nakahata, M., Nakajima, T., Nakano, Y., Nakayama, S., Okada, T., Okamoto, K., Orii, A., Sato, K., Sekiya, H., Shiozawa, M., Sonoda, Y., Suzuki, Y., Takeda, A., Takemoto, Y., Takenaka, A., Tanaka, H., Tasaka, S., Tomura, T., Ueno, K., Watanabe, S., Yano, T., Yokozawa, T., Han, S., Irvine, T., Kajita, T., Kametani, I., Kaneyuki, K., Lee, K. P., McLachlan, T., Okumura, K., Richard, E., Tashiro, T., Wang, R., Xia, J., Megias, G. D., Bravo-Berguño, D., Labarga, L., Zaldivar, B., Goldhaber, M., Blaszczyk, F. d. M., Gustafson, J., Kachulis, C., Kearns, E., Raaf, J. L., Stone, J. L., Sulak, L. R., Sussman, S., Wan, L., Wester, T., Pointon, B. W., Bian, J., Carminati, G., Elnimr, M., Griskevich, N. J., Kropp, W. R., Locke, S., Renshaw, A., Smy, M. B., Sobel, H. W., Takhistov, V., Weatherly, P., Ganezer, K. S., Hartfiel, B. L., Hill, J., Keig, W. E., Hong, N., Kim, J. Y., Lim, I. T., Park, R. G., Akiri, T., Bodur, B., Himmel, A., Li, Z., O'Sullivan, E., Scholberg, K., Walter, C. W., Wongjirad, T., Bernard, L., Coffani, A., Drapier, O., Hedri, S. El, Giampaolo, A., Imber, J., Mueller, Th. A., Paganini, P., Quilain, B., Ishizuka, T., Nakamura, T., Jang, J. S., Choi, K., Learned, J. G., Matsuno, S., Smith, S. N., Amey, J., Anthony, L. H. V., Litchfield, R. P., Ma, W. Y., Marin, D., Sztuc, A. A., Uchida, Y., Wascko, M. O., Berardi, V., Catanesi, M. G., Intonti, R. A., Radicioni, E., Calabria, N. F., De Rosa, G., Machado, L. N., Collazuol, G., Iacob, F., Lamoureux, M., Ospina, N., Ludovici, L., Gonin, M., Pronost, G., Maekawa, Y., Nishimura, Y., Cao, S., Friend, M., Hasegawa, T., Ishida, T., Ishii, T., Jakkapu, M., Kobayashi, T., Matsubara, T., Nakadaira, T., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Boschi, T., Di Lodovico, F., Migenda, J., Sedgwick, S. Molina, Taani, M., Zsoldos, S., Abe, KE., Hasegawa, M., Isobe, Y., Kotsar, Y., Miyabe, H., Ozaki, H., Shiozawa, T., Sugimoto, T., Suzuki, A. T., Takeuchi, Y., Yamamoto, S., Ali, A., Ashida, Y., Bronner, C., Feng, J., Hayashino, T., Hiraki, T., Hirota, S., Huang, K., Jiang, M., Kikawa, T., Mori, M., Murakami, A., Nakamura, KE., Nakaya, T., Patel, N. D., Suzuki, K., Takahashi, S., Tateishi, K., Wendell, R. A., Yasutome, K., Fernandez, P., McCauley, N., Mehta, P., Pritchard, A., Tsui, K. M., Fukuda, Y., Itow, Y., Menjo, H., Mitsuka, G., Murase, M., Muto, F., Niwa, T., Tsukada, T. Suzuki M., Frankiewicz, K., Mijakowski, P., Hignight, J., Jiang, J., Jung, C. K., Li, X., Palomino, J. L., Santucci, G., Vilela, C., Wilking, M. J., Yanagisawa, C., Fukuda, D., Hagiwara, K., Harada, M., Horai, T., Ishino, H., Ito, S., Kayano, T., Kibayashi, A., Kitagawa, H., Koshio, Y., Ma, W., Mori, T., Nagata, H., Piplani, N., Sakai, S., Sakuda, M., Takahira, Y., Xu, C., Yamaguchi, R., Kuno, Y., Barr, G., Barrow, D., Cook, L., Goldsack, A., Samani, S., Simpson, C., Wark, D., Nova, F., Tacik, R., Yang, J. Y., Cole, A., Jenkins, S. J., Malek, M., McElwee, J. M., Stone, O., Thiesse, M. D., Thompson, L. F., Okazawa, H., Choi, Y., Kim, S. B., Yu, I., Ichikawa, A. K., Ito, K., Nishijima, K., Calland, R. G., de Perio, P., Martens, K., Murdoch, M., Vagins, M. R., Koshiba, M., Totsuka, Y., Iwamoto, K., Nakajima, Y., Ogawa, N., Suda, Y., Yokoyama, M., Hamabe, D., Izumiyama, S., Kuze, M., Okajima, Y., Tanaka, M., Yoshida, T., Inomoto, M., Ishitsuka, M., Ito, H., Matsumoto, R., Ohta, K., Shinoki, M., Martin, J. F., Nantais, C. M., Tanaka, H. A., Towstego, T., Akutsu, R., Hartz, M., Konaka, A., Prouse, N. W., Chen, S., Xu, B. D., Zhang, Y., Berkman, S., Tobayama, S., Connolly, K., Wilkes, R. J., Posiadala-Zezula, M., Hadley, D., Richards, B., Jamieson, B., Walker, J., Marti, Ll., Minamino, A., Pintaudi, G., Sano, S., and Sasaki, R.
Subjects: High Energy Physics - Experiment, Astrophysics - Instrumentation and Methods for Astrophysics, Physics - Instrumentation and Detectors
Abstract: We present the development of neutron-tagging techniques in Super-Kamiokande IV using a neural network analysis. The detection efficiency of neutron capture on hydrogen is estimated to be 26%, with a mis-tag rate of 0.016 per neutrino event. The uncertainty of the tagging efficiency is estimated to be 9.0%. Measurement of the tagging efficiency with data from an Americium-Beryllium calibration agrees with this value within 10%. The tagging procedure was performed on 3,244.4 days of SK-IV atmospheric neutrino data, identifying 18,091 neutrons in 26,473 neutrino events. The fitted neutron capture lifetime was measured as 218 \pm 9 \mu s.
Published: 2022
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21. Search for proton decay via $p\rightarrow \mu^+K^0$ in 0.37 megaton-years exposure of Super-Kamiokande

Author: Collaboration, Super-Kamiokande, Matsumoto, R., Abe, K., Hayato, Y., Hiraide, K., Ieki, K., Ikeda, M., Kameda, J., Kanemura, Y., Kaneshima, R., Kashiwagi, Y., Kataoka, Y., Miki, S., Mine, S., Miura, M., Moriyama, S., Nakano, Y., Nakahata, M., Nakayama, S., Noguchi, Y., Okamoto, K., Sato, K., Sekiya, H., Shiba, H., Shimizu, K., Shiozawa, M., Sonoda, Y., Suzuki, Y., Takeda, A., Takemoto, Y., Takenaka, A., Tanaka, H., Watanabe, S., Yano, T., Han, S., Kajita, T., Okumura, K., Tashiro, T., Tomiya, T., Wang, X., Xia, J., Yoshida, S., Megias, G. D., Fernandez, P., Labarga, L., Ospina, N., Zaldivar, B., Pointon, B. W., Kearns, E., Raaf, J. L., Wan, L., Wester, T., Bian, J., Griskevich, N. J., Kropp, W. R., Locke, S., Smy, M. B., Sobel, H. W., Takhistov, V., Yankelevich, A., Hill, J., Kim, J. Y., Lim, I. T., Park, R. G., Bodur, B., Scholberg, K., Walter, C. W., Bernard, L., Coffani, A., Drapier, O., Hedri, S. El, Giampaolo, A., Mueller, Th. A., Santos, A. D., Paganini, P., Quilain, B., Ishizuka, T., Nakamura, T., Jang, J. S., Learned, J. G., Choi, K., Cao, S., Anthony, L. H. V., Martin, D., Scott, M., Sztuc, A. A., Uchida, Y., Berardi, V., Catanesi, M. G., Radicioni, E., Calabria, N. F., Machado, L. N., De Rosa, G., Collazuol, G., Iacob, F., Lamoureux, M., Mattiazzi, M., Ludovici, L., Gonin, M., Pronost, G., Fujisawa, C., Maekawa, Y., Nishimura, Y., Friend, M., Hasegawa, T., Ishida, T., Kobayashi, T., Jakkapu, M., Matsubara, T., Nakadaira, T., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Boschi, T., Di Lodovico, F., Gao, J., Goldsack, A., Katori, T., Migenda, J., Taani, M., Xie, Z., Zsoldos, S., Kotsar, Y., Ozaki, H., Suzuki, A. T., Takeuchi, Y., Yamamoto, S., Bronner, C., Feng, J., Kikawa, T., Mori, M., Nakaya, T., Wendell, R. A., Yasutome, K., Jenkins, S. J., McCauley, N., Mehta, P., Tsui, K. M., Tarrant, A., Fukuda, Y., Itow, Y., Menjo, H., Ninomiya, K., Lagoda, J., Lakshmi, S. M., Mandal, M., Mijakowski, P., Prabhu, Y. S., Zalipska, J., Jiang, M. Jia J., Jung, C. K., Wilking, M. J., Yanagisawa, C., Harada, M., Ishino, H., Ito, S., Kitagawa, H., Koshio, Y., Ma, W., Nakanishi, F., Sakai, S., Barr, G., Barrow, D., Cook, L., Samani, S., Wark, D., Holin, A., Nova, F., Yang, J. Y., Malek, M., McElwee, J. M., Stone, O., Thiesse, M. D., Thompson, L. F., Okazawa, H., Kim, S. B., Kwon, E., Seo, J. W., Yu, I., Ichikawa, A. K., Nakamura, K. D., Tairafune, S., Nishijima, K., Koshiba, M., Iwamoto, K., Nakagiri, K., Nakajima, Y., Shima, S., Taniuchi, N., Yokoyama, M., Martens, K., de Perio, P., Vagins, M. R., Kuze, M., Izumiyama, S., Inomoto, M., Ishitsuka, M., Ito, H., Kinoshita, T., Ommura, Y., Shigeta, N., Shinoki, M., Suganuma, T., Yamauchi, K., Martin, J. F., Tanaka, H. A., Towstego, T., Akutsu, R., Gousy-Leblanc, V., Hartz, M., Konaka, A., Li, X., Prouse, N. W., Chen, S., Xu, B. D., Zhang, B., Posiadala-Zezula, M., Boyd, S. B., Hadley, D., Nicholson, M., O'Flaherty, M., Richards, B., Ali, A., Jamieson, B., Marti, Ll., Minamino, A., Pintaudi, G., Sano, S., Suzuki, S., and Wada, K.
Subjects: High Energy Physics - Experiment
Abstract: We searched for proton decay via $p\to\mu^+K^0$ in 0.37\,Mton$\cdot$years of data collected between 1996 and 2018 from the Super-Kamiokande water Cherenkov experiment. The selection criteria were defined separately for $K^0_S$ and $K^0_L$ channels. No significant event excess has been observed. As a result of this analysis, which extends the previous search by an additional 0.2\,Mton$\cdot$years of exposure and uses an improved event reconstruction, we set a lower limit of $3.6\times10^{33}$ years on the proton lifetime., Comment: 13 pages, 11 figures
Published: 2022

22. Search for supernova bursts in Super-Kamiokande IV

Author: collaboration, The Super-Kamiokande, Mori, M., Abe, K., Hayato, Y., Hiraide, K., Ieki, K., Ikeda, M., Imaizumi, S., Kameda, J., Kanemura, Y., Kaneshima, R., Kashiwagi, Y., Kataoka, Y., Miki, S., Mine, S., Miura, M., Moriyama, S., Nagao, Y., Nakahata, M., Nakano, Y., Nakayama, S., Noguchi, Y., Okada, T., Okamoto, K., Orii, A., Sato, K., Sekiya, H., Shiba, H., Shimizu, K., Shiozawa, M., Sonoda, Y., Suzuki, Y., Takeda, A., Takemoto, Y., Takenaka, A., Tanaka, H., Tomiya, T., Watanabe, S., Yano, T., Yoshida, S., Han, S., Kajita, T., Okumura, K., Tashiro, T., Wang, X., Xia, J., Megias, G. D., Bravo-Berguno, D., Fernandez, P., Labarga, L., Ospina, N., Zaldivar, B., Zsoldos, S., Pointon, B. W., Blaszczyk, F. d. M., Kearns, E., Raaf, J. L., Stone, J. L., Wan, L., Wester, T., Bian, J., Griskevich, N. J., Kropp, W. R., Locke, S., Smy, M. B., Sobel, H. W., Takhistov, V., Yankelevich, Hill, J., Kim, J. Y., Lim, I. T., Park, R. G., Bodur, B., Scholberg, K., Walter, C. W., Bernard, L., Coffani, A., Drapier, O., Hedri, S. El, Giampaolo, A., Mueller, Th. A., Paganini, P., Quilain, B., Santos, A. D., Ishizuka, T., Nakamura, T., Jang, J. S., Learned, J. G., Anthony, L. H. V., Martin, D., Scott, M., Sztuc, A. A., Uchida, Y., Berardi, V., Catanesi, M. G., Radicioni, E., Calabria, N. F., Machado, L. N., De Rosa, G., Collazuol, G., Iacob, F., Lamoureux, M., Mattiazzi, M., Ludovici, L., Gonin, M., Pronost, G., Maekawa, Y., Nishimura, Y., Fujisawa, C., Friend, M., Hasegawa, T., Ishida, T., Kobayashi, T., Jakkapu, M., Matsubara, T., Nakadaira, T., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Ozaki, H., Shiozawa, T., Suzuki, A. T., Takeuchi, Y., Yamamoto, S., Kotsar, Y., Ashida, Y., Bronner, C., Feng, J., Hirota, S., Kikawa, T., Nakaya, T., Wendell, R. A., Yasutome, K., McCauley, N., Mehta, P., Tsui, K. M., Fukuda, Y., Itow, Y., Menjo, H., Ninomiya, K., Niwa, T., Tsukada, M., Lagoda, J., Lakshmi, S. M., Mijakowski, P., Zalipska, J., Mandal, M., Prabhu, Y. S., Jiang, J., Jung, C. K., Vilela, C., Wilking, M. J., Yanagisawa, C., Jia, M., Hagiwara, K., Harada, M., Horai, T., Ishino, H., Ito, S., Kitagawa, H., Koshio, Y., Ma, W., Nakanishi, F., Piplani, N., Sakai, S., Barr, G., Barrow, D., Cook, L., Samani, S., Wark, D., Nova, F., Boschi, T., Gao, J., Goldsack, A., Katori, T., Di Lodovico, F., Migenda, J., Taani, M., Yang, J. Y., Jenkins, S. J., Malek, M., McElwee, J. M., Stone, O., Thiesse, M. D., Thompson, L. F., Okazawa, H., Kim, S. B., Seo, J. W., Yu, I., Nishijima, K., Koshiba, M., Nakagiri, K., Nakajima, Y., Iwamoto, K., Taniuchi, N., Yokoyama, M., Martens, K., de Perio, P., Vagins, M. R., Kuze, M., Izumiyama, S., Yoshida, T., Inomoto, M., Ishitsuka, M., Ito, H., Kinoshita, T., Matsumoto, R., Ohta, K., Ommura, Y., Shigeta, N., Shinoki, M., Suganuma, T., Yamauchi, K., Martin, J. F., Tanaka, H. A., Towstego, T., Akutsu, R., Gousy-Leblanc, V., Hartz, M., Konaka, A., Prouse, N. W., Chen, S., Xu, B. D., Zhang, B., Posiadala-Zezula, M., Hadley, D., Nicholson, M., Flaherty, M. O', Richards, B., Ali, A., Jamieson, B., Walker, J., Marti, Ll., Minamino, A., Pintaudi, G., Sasaki, R., Sano, S., Suzuki, S., Wada, K., Cao, S., Ichikawa, A., Nakamura, K. D., and Tairafun, S.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, High Energy Physics - Experiment
Abstract: Super-Kamiokande has been searching for neutrino bursts characteristic of core-collapse supernovae continuously, in real time, since the start of operations in 1996. The present work focuses on detecting more distant supernovae whose event rate may be too small to trigger in real time, but may be identified using an offline approach. The analysis of data collected from 2008 to 2018 found no evidence of distant supernovae bursts. This establishes an upper limit of 0.29 year$^{-1}$ on the rate of core-collapse supernovae out to 100 kpc at 90% C.L.. For supernovae that fail to explode and collapse directly to black holes the limit reaches to 300 kpc.
Published: 2022
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23. Study on the accidental background of the JSNS2 experiment

Author: Lee, D. H., Ajimura, S., Cheoun, M. K., Choi, J. H., Choi, J. Y., Dodo, T., Goh, J., Haga, K., Harada, M., Hasegawa, S., Hiraiwa, T., Hwang, W., Jang, H. I., Jang, J. S., Jeon, H., Jeon, S., Joo, K. K., Jung, D. E., Kang, S. K., Kasugai, Y., Kawasaki, T., Kim, E. J., Kim, J. Y., Kim, S. B., Kim, W., Kinoshita, H., Konno, T., Lim, I. T., Little, C., Marzec, E., Maruyama, T., Masuda, S., Meigo, S., Monjushiro, S., Moon, D. H., Nakano, T., Niiyama, M., Nishikawa, K., Pac, M. Y., Park, H. W., Park, J. S., Park, R. G., Peeters, S. J. M., Rott, C., Sakai, K., Sakamoto, S., Shima, T., Shin, C. D., Spitz, J., Suekane, F., Sugaya, Y., Suzuya, K., Taira, M., Yamaguchi, Y., Yeh, M., Yeo, I. S., Yoo, C., and Yu, I.
Published: 2024
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24. Pre-Supernova Alert System for Super-Kamiokande

Author: Collaboration, Super-Kamiokande, Machado, L. N., Abe, K., Hayato, Y., Hiraide, K., Ieki, K., Ikeda, M., Kameda, J., Kanemura, Y., Kaneshima, R., Kashiwagi, Y., Kataoka, Y., Miki, S., Mine, S., Miura, M., Moriyama, S., Nakano, Y., Nakahata, M., Nakayama, S., Noguchi, Y., Okamoto, K., Sato, K., Sekiya, H., Shiba, H., Shimizu, K., Shiozawa, M., Sonoda, Y., Suzuki, Y., Takeda, A., Takemoto, Y., Takenaka, A., Tanaka, H., Watanabe, S., Yano, T., de Perio, P., Martens, K., Vagins, M. R., Bian, J., Griskevich, N. J., Kropp, W. R., Locke, S., Smy, M. B., Sobel, H. W., Takhistov, V., Yankelevich, A., Han, S., Kajita, T., Okumura, K., Tashiro, T., Tomiya, T., Wang, X., Xia, J., Yoshida, S., Megias, G. D., Fernandez, P., Labarga, L., Ospina, N., Zaldivar, B., Pointon, B. W., Akutsu, R., Gousy-Leblanc, V., Hartz, M., Konaka, A., Prouse, N. W., Kearns, E., Raaf, J. L., Wan, L., Wester, T., Hill, J., Kim, J. Y., Lim, I. T., Park, R. G., Bodur, B., Scholberg, K., Walter, C. W., Bernard, L., Coffani, A., Drapier, O., Hedri, S. El, Giampaolo, A., Mueller, Th. A., Santos, A. D., Paganini, P., Quilain, B., Ishizuka, T., Nakamura, T., Jang, J. S., Learned, J. G., Cao, S., Choi, K., Anthony, L. H. V., Martin, D., Scott, M., Sztuc, A. A., Uchida, Y., Berardi, V., Catanesi, M. G., Radicioni, E., Calabria, N. F., De Rosa, G., Collazuol, G., Iacob, F., Lamoureux, M., Mattiazzi, M., Ludovici, L., Gonin, M., Pronost, G., Fujisawa, C., Maekawa, Y., Nishimura, Y., Sasaki, R., Friend, M., Hasegawa, T., Ishida, T., Jakkapu, M., Kobayashi, T., Matsubara, T., Nakadaira, T., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Boschi, T., Di Lodovico, F., Gao, J., Goldsack, A., Katori, T., Migenda, J., Taani, M., Zsoldos, S., Kotsar, Y., Ozaki, H., Suzuki, A. T., Takeuchi, Y., Yaamoto, S., Bronner, C., Feng, J., Kikawa, T., Mori, M., Nakaya, T., Wendell, R. A., Yasutome, K., Jenkins, S. J., McCauley, N., Mehta, P., Tsui, K. M., Fukuda, Y., Itow, Y., Menjo, H., Ninomiya, K., Lagoda, J., Lakshmi, S. M., Mandal, M., Mijakowski, P., Prabhu, Y. S., Zalipska, J., Jia, M., Jiang, J., Jung, C. K., Wilking, M. J., Yanagisawa, C., Harada, M., Ishino, H., Ito, S., Kitagawa, H., Koshio, Y., Ma, W., Nakanishi, F., Sakai, S., Barr, G., Barrow, D., Cook, L., Samani, S., Wark, D., Nova, F., Yang, J. Y., Malek, M., McElwee, J. M., Stone, O., Thiesse, M. D., Thompson, L. F., Okazawa, H., Kim, S. B., Seo, J. W., Yu, I., Ichikawa, A. K., Nakamura, K. D., Tairafune, S., Nishijima, K., Iwamoto, K., Nakagiri, K., Nakajima, Y., Taniuchi, N., Yokoyama, M., Izumiyama, S., Kuze, M., Inomoto, M., Ishitsuka, M., Ito, H., Kinoshita, T., Matsumoto, R., Ommura, Y., Shigeta, N., Shinoki, M., Suganuma, T., Yonenaga, M., Martin, J. F., Tanaka, H. A., Towstego, T., Chen, S., Xu, B. D., Zhang, B., Posiadala-Zezula, M., Hadley, D., Nicholson, M., O'Flaherty, M., Richards, B., Ali, A., Jamieson, B., Marti, Ll., Minamino, A., Pintaudi, G., Sano, S., Suzuki, S., and Wada, K.
Subjects: High Energy Physics - Experiment, Astrophysics - High Energy Astrophysical Phenomena, Physics - Instrumentation and Detectors
Abstract: In 2020, the Super-Kamiokande (SK) experiment moved to a new stage (SK-Gd) in which gadolinium (Gd) sulfate octahydrate was added to the water in the detector, enhancing the efficiency to detect thermal neutrons and consequently improving the sensitivity to low energy electron anti-neutrinos from inverse beta decay (IBD) interactions. SK-Gd has the potential to provide early alerts of incipient core-collapse supernovae through detection of electron anti-neutrinos from thermal and nuclear processes responsible for the cooling of massive stars before the gravitational collapse of their cores. These pre-supernova neutrinos emitted during the silicon burning phase can exceed the energy threshold for IBD reactions. We present the sensitivity of SK-Gd to pre-supernova stars and the techniques used for the development of a pre-supernova alarm based on the detection of these neutrinos in SK, as well as prospects for future SK-Gd phases with higher concentrations of Gd. For the current SK-Gd phase, high-confidence alerts for Betelgeuse could be issued up to nine hours in advance of the core-collapse itself., Comment: 20 pages
Published: 2022
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25. Measurement of cosmogenic $^9$Li and $^8$He production rates at RENO

Author: Lee, H. G., Choi, J. H., Jang, H. I., Jang, J. S., Jeon, S. H., Joo, K. K., Jung, D. E., Kim, J. G., Kim, J. H., Kim, J. Y., Kim, S. B., Kim, S. Y., Kim, W., Kwon, E., Lee, D. H., Lee, W. J., Lim, I. T., Moon, D. H., Pac, M. Y., Park, J. S., Park, R. G., Seo, H., Seo, J. W., Shin, C. D., Yang, B. S., Yoo, J., Yoon, S. G., Yeo, I. S., and Yu, I.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: We report the measured production rates of unstable isotopes $^9$Li and $^8$He produced by cosmic muon spallation on $^{12}$C using two identical detectors of the RENO experiment. Their beta-decays accompanied by a neutron make a significant contribution to backgrounds of reactor antineutrino events in precise determination of the smallest neutrino mixing angle. The mean muon energy of its near (far) detector with an overburden of 120 (450) m.w.e. is estimated as 33.1 +- 2.3 (73.6 +- 4.4) GeV. Based on roughly 3100 days of data, the cosmogenic production rate of $^9$Li ($^8$He) isotope is measured to be 44.2 +- 3.1 (10.6 +- 7.4) per day at near detector and 10.0 +- 1.1 (2.1 +- 1.5) per day at far detector. This corresponds to yields of $^9$Li ($^8$He), 4.80 +- 0.36 (1.15 +- 0.81) and 9.9 +- 1.1 (2.1 +- 1.5) at near and far detectors, respectively, in a unit of 10$^{-8}$ $\mu^{-1}$ g${^-1}$ cm${^2}$. Combining the measured $^9$Li yields with other available underground measurements, an excellent power-law relationship of the yield with respect to the mean muon energy is found to have an exponent of $\alpha$ = 0.75 +- 0.05., Comment: 11 pages, 14 figures
Published: 2022
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26. Testing Non-Standard Interactions Between Solar Neutrinos and Quarks with Super-Kamiokande

Author: Collaboration, Super-Kamiokande, Weatherly, P., Abe, K., Bronner, C., Hayato, Y., Hiraide, K., Ikeda, M., Iyogi, K., Kameda, J., Kanemura, Y., Kataoka, Y., Kato, Y., Kishimoto, Y., Miki, S., Miura, M., Moriyama, S., Mochizuki, T., Nakahata, M., Nakano, Y., Nakayama, S., Okada, T., Okamoto, K., Orii, A., Pronost, G., Sato, K., Sekiya, H., Shiozawa, M., Sonoda, Y., Suzuki, Y., Takeda, A., Takemoto, Y., Takenaka, A., Tanaka, H., Tasaka, S., Wang, X., Watanabe, S., Yano, T., Han, S., Kajita, T., Kaneyuki, K., Okumura, K., Tashiro, T., Wang, R., Xia, J., Megias, G. D., Labarga, L., Zaldivar, B., Pointon, B. W., Blaszczyk, F. d. M., Kachulis, C., Kearns, E., Raaf, J. L., Stone, J. L., Sulak, L. R., Sussman, S., Wan, L., Wester, T., Berkman, S., Tobayama, S., Bian, J., Elnimr, M., Griskevich, N. J., Kropp, W. R., Locke, S., Mine, S., Smy, M. B., Sobel, H. W., Takhistov, V., Yankelevich, A., Ganezer, K. S., Hill, J., Kim, J. Y., Lim, I. T., Park, R. G., Bodur, B., Li, Z., Scholberg, K., Walter, C. W., Bernard, L., Coffani, A., Drapier, O., Giampaolo, A., Hedri, S. El, Imber, J., Mueller, Th. A., Paganini, P., Quilain, B., Santos, A. D., Ishizuka, T., Nakamura, T., Jang, J. S., Learned, J. G., Matsuno, S., Cao, S., Amey, J., Anthony, L. H. V., Litchfield, R. P., Ma, W. Y., Martin, D., Scott, M., Sztuc, A. A., Uchida, Y., Wascko, M. O., Berardi, V., Catanesi, M. G., Intonti, R. A., Radicioni, E., Calabria, N. F., Machado, L. N., De Rosa, G., Collazuol, G., Iacob, F., Lamoureux, M., Mattiazzi, M., Ospina, N., Ludovici, L., Gonin, M., Maekawa, Y., Nishimura, Y., Friend, M., Hasegawa, T., Ishida, T., Jakkapu, M., Kobayashi, T., Matsubara, T., Nakadaira, T., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Boschi, T., Di Lodovico, F., Gao, J., Katori, T., Migenda, J., Taani, M., Zsoldos, S., Abe, KE., Hasegawa, M., Isobe, Y., Kotsar, Y., Miyabe, H., Ozaki, H., Sugimoto, T., Suzuki, A. T., Takeuchi, Y., Yamamoto, S., Ashida, Y., Feng, J., Hayashino, T., Hirota, S., Jiang, M., Kikawa, T., Mori, M., Nakaya, T., Wendell, R. A., Yasutome, K., Fernandez, P., McCauley, N., Mehta, P., Pritchard, A., Tsui, K. M., Fukuda, Y., Itow, Y., Menjo, H., Murase, M., Frankiewicz, K., Lagoda, J., Lakshmi, S. M., Mandal, M., Mijakowski, P., Prabhu, Y. S., Zalipska, J., Jia, M., Jiang, J., Jung, C. K., Li, X., Palomino, J. L., Santucci, G., Vilela, C., Wilking, M. J., Yanagisawa, C., Fukuda, D., Hagiwara, K., Harada, M., Ishino, H., Ito, S., Kitagawa, H., Koshio, Y., Ma, W., Sakai, S., Sakuda, M., Takahira, Y., Xu, C., Kuno, Y., Barr, G., Barrow, D., Cook, L., Goldsack, A., Samani, S., Simpson, C., Wark, D., Sedgwick, S. Molina, Tacik, R., Nova, F., Yang, J. Y., Jenkins, S. J., Malek, M., McElwee, J. M., Stone, O., Thiesse, M. D., Thompson, L. F., Okazawa, H., Choi, Y., Kim, S. B., Seo, J. W., Yu, I., Ichikawa, A., Nakamura, K. D., Nishijima, K., Koshiba, M., Iwamoto, K., Nakagiri, K., Nakajima, Y., Suda, Y., Taniuchi, N., Yokoyama, M., Martens, K., Murdoch, M., Vagins, M. R., Hamabe, D., Izumiyama, S., Kuze, M., Okajima, Y., Yoshida, T., Inomoto, M., Ishitsuka, M., Ito, H., Kinoshita, T., Matsumoto, R., Shinoki, M., Suganuma, T., Yonenaga, M., Martin, J. F., Nantais, C. M., Tanaka, H. A., Towstego, T., Akutsu, R., de Perio, P., Gousy-Leblanc, V., Hartz, M., Konaka, A., Prouse, N. W., Chen, S., Xu, B. D., Zhang, B., Posiadala-Zezula, M., Hadley, D., Nicholson, M., O'Flaherty, M., Richards, B., Ali, A., Jamieson, B., Giorgio, P., Marti, Ll., Minamino, A., Pintaudi, G., Sano, S., Sasaki, R., and Wada, K.
Subjects: High Energy Physics - Experiment, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Solar and Stellar Astrophysics
Abstract: Non-Standard Interactions (NSI) between neutrinos and matter affect the neutrino flavor oscillations. Due to the high matter density in the core of the Sun, solar neutrinos are suited to probe these interactions. Using the $277$ kton-yr exposure of Super-Kamiokande to $^{8}$B solar neutrinos, we search for the presence of NSI. Our data favors the presence of NSI with down quarks at 1.8$\sigma$, and with up quarks at 1.6$\sigma$, with the best fit NSI parameters being ($\epsilon_{11}^{d},\epsilon_{12}^{d}$) = (-3.3, -3.1) for $d$-quarks and ($\epsilon_{11}^{u},\epsilon_{12}^{u}$) = (-2.5, -3.1) for $u$-quarks. After combining with data from the Sudbury Neutrino Observatory and Borexino, the significance increases by 0.1$\sigma$., Comment: Author: Pierce Weatherly 25 pages. To be submitted to Physical Review D
Published: 2022

27. New Methods and Simulations for Cosmogenic Induced Spallation Removal in Super-Kamiokande-IV

Author: Collaboration, Super-Kamiokande, Locke, S., Coffani, A., Abe, K., Bronner, C., Hayato, Y., Ikeda, M., Imaizumi, S., Ito, H., Kameda, J., Kataoka, Y., Miura, M., Moriyama, S., Nagao, Y., Nakahata, M., Nakajima, Y., Nakayama, S., Okada, T., Okamoto, K., Orii, A., Pronost, G., Sekiya, H., Shiozawa, M., Sonoda, Y., Suzuki, Y., Takeda, A., Takemoto, Y., Takenaka, A., Tanaka, H., Yano, T., Hirade, K., Kanemura, Y., Miki, S., Watabe, S., Han, S., Kajita, T., Okumura, K., Tashiro, T., Xia, J., Wang, X., Megias, G. D., Bravo-Berguño, D., Labarga, L., Marti, Ll., Zaldivar, B., Pointon, B. W., Blaszczyk, F. d. M., Kearns, E., Raaf, J. L., Stone, J. L., Wan, L., Wester, T., Bian, J., Griskevich, N. J., Kropp, W. R., Mine, S., Yankelevic, A., Smy, M. B., Sobel, H. W., Takhistov, V., Hill, J., Kim, J. Y., Lim, I. T., Park, R. G., Bodur, B., Scholberg, K., Walter, C. W., Bernard, L., Drapier, O., Hedri, S. El, Giampaolo, A., Gonin, M., Mueller, Th. A., Paganini, P., Quilain, B., Santos, A. D., Ishizuka, T., Nakamura, T., Jang, J. S., Learned, J. G., Anthony, L. H. V., Sztuc, A. A., Uchida, Y., Martin, D., Scott, M., Berardi, V., Catanesi, M. G., Radicioni, E., Calabria, N. F., Machado, L. N., De Rosa, G., Collazuol, G., Iacob, F., Lamoureux, M., Ospina, N., Mattiazzi, M., Ludovici, L., Nishimura, Y., Maewaka, Y., Cao, S., Friend, M., Hasegawa, T., Ishida, T., Kobayashi, T., Jakkapu, M., Matsubara, T., Nakadaira, T., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Nakano, Y., Shiozawa, T., Suzuki, A. T., Takeuchi, Y., Yamamoto, S., Kotsar, Y., Ozaki, H., Ali, A., Ashida, Y., Feng, J., Hirota, S., Ichikawa, A. K., Kikawa, T., Mori, M., Nakaya, T., Wendell, R. A., Yasutome, K., Fernandez, P., McCauley, N., Mehta, P., Tsui, K. M., Fukuda, Y., Itow, Y., Menjo, H., Niwa, T., Sato, K., Tsukada, M., Mijakowski, P., Lagoda, J., Lakshmi, S. M., Zalipska, J., Jung, C. K., Vilela, C., Wilking, M. J., Yanagisawa, C., Jiang, J., Hagiwara, K., Harada, M., Horai, T., Ishino, H., Ito, S., Koshio, Y., Ma, W., Piplani, N., Sakai, S., Kitagawa, H., Barr, G., Barrow, D., Cook, L., Goldsack, A., Samani, S., Wark, D., Nova, F., Boschi, T., Di Lodovico, F., Taani, M., Zsoldos, S., Gao, J., Migenda, J., Yang, J. Y., Jenkins, S. J., Malek, M., McElwee, J. M., Stone, O., Thiesse, M. D., Thompson, L. F., Okazawa, H., Kim, S. B., Yu, I., Seo, J. W., Nishijima, K., Koshiba, M., Iwamoto, K., Ogawa, N., Yokoyama, M., Martens, K., Vagins, M. R., Nakagiri, K., Kuze, M., Izumiyama, S., Yoshida, T., Inomoto, M., Ishitsuka, M., Matsumoto, R., Ohta, K., Shinoki, M., Suganuma, T., Kinoshita, T., Martin, J. F., Tanaka, H. A., Towstego, T., Akutsu, R., Hartz, M., Konaka, A., de Perio, P., Prouse, N. W., Chen, S., Xu, B. D., Zhang, Y., Posiadala-Zezula, M., Richards, B., Jamieson, B., Walker, J., Minamino, A., Pintaudi, G., and Sasaki, R.
Subjects: High Energy Physics - Experiment, Astrophysics - High Energy Astrophysical Phenomena
Abstract: Radioactivity induced by cosmic muon spallation is a dominant source of backgrounds for $\mathcal{O}(10)~$MeV neutrino interactions in water Cherenkov detectors. In particular, it is crucial to reduce backgrounds to measure the solar neutrino spectrum and find neutrino interactions from distant supernovae. In this paper we introduce new techniques to locate muon-induced hadronic showers and efficiently reject spallation backgrounds. Applying these techniques to the solar neutrino analysis with an exposure of $2790\times22.5$~kton.day increases the signal efficiency by $12.6\%$, approximately corresponding to an additional year of detector running. Furthermore, we present the first spallation simulation at SK, where we model hadronic interactions using FLUKA. The agreement between the isotope yields and shower pattern in this simulation and in the data gives confidence in the accuracy of this simulation, and thus opens the door to use it to optimize muon spallation removal in new data with gadolinium-enhanced neutron capture detection.
Published: 2021

28. Characterization of the correlated background for a sterile neutrino search using the first dataset of the JSNS$^2$ experiment

Author: Hino, Y., Ajimura, S., Cheoun, M. K., Choi, J. H., Dodo, T., Furuta, H., Goh, J., Haga, K., Harada, M., Hasegawa, S., Hiraiwa, T., Hwang, W., Jang, H. I., Jang, J. S., Jeon, H., Jeon, S., Joo, K. K., Jordan, J. R., Jung, D. E., Kang, S. K., Kasugai, Y., Kawasaki, T., Kim, E. J., Kim, J. Y., Kim, S. B., Kim, S. Y., Kim, W., Kinoshita, H., Konno, T., Lee, C. Y., Lee, D. H., Lee, S., Lim, I. T., Little, C., Marzec, E., Maruyama, T., Masuda, S., Meigo, S., Monjushiro, S., Moon, D. H., Nakano, T., Niiyama, M., Nishikawa, K., Nomachi, M., Pac, M. Y., Park, J. S., Park, R. G., Peeters, S. J. M., Ray, H., Rott, C., Sakai, K., Sakamoto, S., Shima, T., Shin, C. D., Spitz, J., Suekane, F., Sugaya, Y., Suzuya, K., Taira, M., Ujiie, R., Yamaguchi, Y., Yeh, M., Yeo, I. S., Yoo, C., and Yu, I.
Subjects: High Energy Physics - Experiment
Abstract: JSNS$^2$ (J-PARC Sterile Neutrino Search at J-PARC Spallation Neutron Source) is an experiment that is searching for sterile neutrinos via the observation of $\bar{\nu}_{\mu} \to \bar{\nu}_{e}$ appearance oscillations using muon decay-at-rest neutrinos. Before dedicated data taking in the first-half of 2021, we performed a commissioning run for 10 days in June 2020. Using the data obtained in this commissioning run, in this paper, we present an estimate of the correlated background which imitates the $\bar{\nu}_{e}$ signal in a sterile neutrino search. In addition, in order to demonstrate future prospects of the JSNS$^2$ experiment, possible pulse shape discrimination improvements towards reducing cosmic ray induced fast neutron background are described., Comment: 7 pages, 3 figures
Published: 2021
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29. Diffuse Supernova Neutrino Background Search at Super-Kamiokande

Author: Collaboration, Super-Kamiokande, Abe, K., Bronner, C., Hayato, Y., Hiraide, K., Ikeda, M., Imaizumi, S., Kameda, J., Kanemura, Y., Kataoka, Y., Miki, S., Miura, M., Moriyama, S., Nagao, Y., Nakahata, M., Nakayama, S., Okada, T., Okamoto, K., Orii, A., Pronost, G., Sekiya, H., Shiozawa, M., Sonoda, Y., Suzuki, Y., Takeda, A., Takemoto, Y., Takenaka, A., Tanaka, H., Watanabe, S., Yano, T., Han, S., Kajita, T., Okumura, K., Tashiro, T., Xia, J., Megias, G. D., Bravo-Bergu, D., Labarga, L., Marti, Ll., Zaldivar, B., Pointon, B. W., Blaszczyk, F. d. M., Kearns, E., Raaf, J. L., Stone, J. L., Wan, L., Wester, T., Bian, J., Griskevich, N. J., Kropp, W. R., Locke, S., Mine, S., Smy, M. B., Sobel, H. W., Takhistov, V., Hill, J., Kim, J. Y., Lim, I. T., Park, R. G., Bodur, B., Scholberg, K., Walter, C. W., Cao, S., Bernard, L., Coffani, A., Drapier, O., Hedri, S. El, Giampaolo, A., Gonin, M., Mueller, Th. A., Paganini, P., Quilain, B., Ishizuka, T., Nakamura, T., Jang, J. S., Learned, J. G., Anthony, L. H. V., Martin, D., Scott, M., Sztuc, A. A., Uchida, Y., Berardi, V., Catanesi, M. G., Radicioni, E., Calabria, N. F., Machado, L. N., De Rosa, G., Collazuol, G., Iacob, F., Lamoureux, M., Mattiazzi, M., Ospina, N., Ludovici, L., Maekawa, Y., Nishimura, Y., Friend, M., Hasegawa, T., Ishida, T., Kobayashi, T., Jakkapu, M., Matsubara, T., Nakadaira, T., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Kotsar, Y., Nakano, Y., Ozaki, H., Shiozawa, T., Suzuki, A. T., Takeuchi, Y., Yamamoto, S., Ali, A., Ashida, Y., Feng, J., Hirota, S., Kikawa, T., Mori, M., Nakaya, T., Wendell, R. A., Yasutome, K., Fernandez, P., McCauley, N., Mehta, P., Tsui, K. M., Fukuda, Y., Itow, Y., Menjo, H., Niwa, T., Sato, K., Tsukada, M., Lagoda, J., Lakshmi, S. M., Mijakowski, P., Zalipska, J., Jiang, J., Jung, C. K., Vilela, C., Wilking, M. J., Yanagisawa, C., Hagiwara, K., Harada, M., Horai, T., Ishino, H., Ito, S., Kitagawa, H., Koshio, Y., Ma, W., Piplani, N., Sakai, S., Barr, G., Barrow, D., Cook, L., Goldsack, A., Samani, S., Wark, D., Nova, F., Boschi, T., Di Lodovico, F., Gao, J., Migenda, J., Taani, M., Zsoldos, S., Yang, J. Y., Jenkins, S. J., Malek, M., McElwee, J. M., Stone, O., Thiesse, M. D., Thompson, L. F., Okazawa, H., Kim, S. B., Seo, J. W., Yu, I., Nishijima, K., Koshiba, M., Iwamoto, K., Nakagiri, K., Nakajima, Y., Ogawa, N., Yokoyama, M., Martens, K., Vagins, M. R., Kuze, M., Izumiyama, S., Yoshida, T., Inomoto, M., Ishitsuka, M., Ito, H., Kinoshita, T., Matsumoto, R., Ohta, K., Shinoki, M., Suganuma, T., Ichikawa, A. K., Martin, J. F., Tanaka, H. A., Towstego, T., Akutsu, R., Gousy-Leblanc, V., Hartz, M., Konaka, A., de Perio, P., Prouse, N. W., Chen, S., Xu, B. D., Zhang, Y., Posiadala-Zezula, M., Hadley, D., O'Flaherty, M., Richards, B., Jamieson, B., Walker, J., Minamino, A., Pintaudi, G., Sano, S., and Sasaki, R.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, High Energy Physics - Experiment
Abstract: A new search for the diffuse supernova neutrino background (DSNB) flux has been conducted at Super-Kamiokande (SK), with a $22.5\times2970$-kton$\cdot$day exposure from its fourth operational phase IV. The new analysis improves on the existing background reduction techniques and systematic uncertainties and takes advantage of an improved neutron tagging algorithm to lower the energy threshold compared to the previous phases of SK. This allows for setting the world's most stringent upper limit on the extraterrestrial $\bar{\nu}_e$ flux, for neutrino energies below 31.3 MeV. The SK-IV results are combined with the ones from the first three phases of SK to perform a joint analysis using $22.5\times5823$ kton$\cdot$days of data. This analysis has the world's best sensitivity to the DSNB $\bar{\nu}_e$ flux, comparable to the predictions from various models. For neutrino energies larger than 17.3 MeV, the new combined $90\%$ C.L. upper limits on the DSNB $\bar{\nu}_e$ flux lie around $2.7$ cm$^{-2}$$\cdot$$\text{sec}^{-1}$, strongly disfavoring the most optimistic predictions. Finally, potentialities of the gadolinium phase of SK and the future Hyper-Kamiokande experiment are discussed., Comment: 42 pages, 37 figures, 14 tables
Published: 2021
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30. First Gadolinium Loading to Super-Kamiokande

Author: Abe, K., Bronner, C., Hayato, Y., Hiraide, K., Ikeda, M., Imaizumi, S., Kameda, J., Kanemura, Y., Kataoka, Y., Miki, S., Miura, M., Moriyama, S., Nagao, Y., Nakahata, M., Nakayama, S., Okada, T., Okamoto, K., Orii, A., Pronost, G., Sekiya, H., Shiozawa, M., Sonoda, Y., Suzuki, Y., Takeda, A., Takemoto, Y., Takenaka, A., Tanaka, H., Watanabe, S., Yano, T., Han, S., Kajita, T., Okumura, K., Tashiro, T., Xia, J., Megias, G. D., Bravo-Berguno, D., Labarga, L., Marti, Ll., Zaldivar, B., Pointon, B. W., Blaszczyk, F. d. M., Kearns, E., Raaf, J. L., Stone, J. L., Wan, L., Wester, T., Bian, J., Griskevich, N. J., Kropp, W. R., Locke, S., Mine, S., Smy, M. B., Sobel, H. W., Takhistov, V., Hill, J., Kim, J. Y., Lim, I. T., Park, R. G., Bodur, B., Scholberg, K., Walter, C. W., Bernard, L., Coffani, A., Drapier, O., Hedri, S. El, Giampaolo, A., Gonin, M., Mueller, Th. A., Paganini, P., Quilain, B., Ishizuka, T., Nakamura, T., Jang, J. S., Learned, J. G., Anthony, L. H. V., Martin, D., Scott, M., Sztuc, A. A., Uchida, Y., Cao, S., Berardi, V., Catanesi, M. G., Radicioni, E., Calabria, N. F., Machado, L. N., De Rosa, G., Collazuol, G., Iacob, F., Lamoureux, M., Mattiazzi, M., Ospina, N., Ludovici, L., Maekawa, Y., Nishimura, Y., Friend, M., Hasegawa, T., Ishida, T., Kobayashi, T., Jakkapu, M., Matsubara, T., Nakadaira, T., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Boschi, T., Gao, J., Di Lodovico, F., Migenda, J., Taani, M., Zsoldos, S., Kotsar, Y., Nakano, Y., Ozaki, H., Shiozawa, T., Suzuki, A. T., Takeuchi, Y., Yamamoto, S., Ali, A., Ashida, Y., Feng, J., Hirota, S., Kikawa, T., Mori, M., Nakaya, T., Wendell, R. A., Yasutome, K., Fernandez, P., McCauley, N., Mehta, P., Tsui, K. M., Fukuda, Y., Itow, Y., Menjo, H., Niwa, T., Sato, K., Tsukada, M., Lagoda, J., Lakshmi, S. M., Mijakowski, P., Zalipska, J., Jiang, J., Jung, C. K., Vilela, C., Wilking, M. J., Yanagisawa, C., Hagiwara, K., Harada, M., Horai, T., Ishino, H., Ito, S., Kitagawa, F., Koshio, Y., Ma, W., Piplani, N., Sakai, S., Barr, G., Barrow, D., Cook, L., Goldsack, A., Samani, S., Wark, D., Nova, F., Yang, J. Y., Jenkins, S. J., Malek, M., McElwee, J. M., Stone, O., Thiesse, M. D., Thompson, L. F., Okazawa, H., Kim, S. B., Seo, J. W., Yu, I., Ichikawa, A. K., Nishijima, K., Koshiba, M., Iwamoto, K., Nakajima, Y., Ogawa, N., Yokoyama, M., Martens, K., Vagins, M. R., Kuze, M., Izumiyama, S., Yoshida, T., Inomoto, M., Ishitsuka, M., Ito, H., Kinoshita, T., Matsumoto, R., Ohta, K., Shinoki, M., Suganuma, T., Martin, J. F., Tanaka, H. A., Towstego, T., Akutsu, R., Hartz, M., Konaka, A., de Perio, P., Prouse, N. W., Chen, S., Xu, B. D., Posiadala-Zezula, M., Hadley, D., O'Flaherty, M., Richards, B., Jamieson, B., Walker, J., Minamino, A., Pintaudi, G., Sano, S., and Sasaki, R.
Subjects: Physics - Instrumentation and Detectors, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract: In order to improve Super-Kamiokande's neutron detection efficiency and to thereby increase its sensitivity to the diffuse supernova neutrino background flux, 13 tons of $\rm Gd_2(\rm SO_4)_3\cdot \rm 8H_2O$ (gadolinium sulfate octahydrate) was dissolved into the detector's otherwise ultrapure water from July 14 to August 17, 2020, marking the start of the SK-Gd phase of operations. During the loading, water was continuously recirculated at a rate of 60 m$^3$/h, extracting water from the top of the detector and mixing it with concentrated $\rm Gd_2(\rm SO_4)_3\cdot \rm 8H_2O$ solution to create a 0.02% solution of the Gd compound before injecting it into the bottom of the detector. A clear boundary between the Gd-loaded and pure water was maintained through the loading, enabling monitoring of the loading itself and the spatial uniformity of the Gd concentration over the 35 days it took to reach the top of the detector. During the subsequent commissioning the recirculation rate was increased to 120 m$^3$/h, resulting in a constant and uniform distribution of Gd throughout the detector and water transparency equivalent to that of previous pure-water operation periods. Using an Am-Be neutron calibration source the mean neutron capture time was measured to be $115\pm1$ $\mu$s, which corresponds to a Gd concentration of $111\pm2$ ppm, as expected for this level of Gd loading. This paper describes changes made to the water circulation system for this detector upgrade, the Gd loading procedure, detector commissioning, and the first neutron calibration measurements in SK-Gd., Comment: 37 pages, 19 Figures, Accepted for publication in Nucl. Instrum. Meth. A
Published: 2021
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31. Search for neutrinos in coincidence with gravitational wave events from the LIGO-Virgo O3a Observing Run with the Super-Kamiokande detector

Author: collaboration, The Super-Kamiokande, Abe, K., Bronner, C., Hayato, Y., Ikeda, M., Imaizumi, S., Kameda, J., Kanemura, Y., Kataoka, Y., Miki, S., Miura, M., Moriyama, S., Nagao, Y., Nakahata, M., Nakayama, S., Okada, T., Okamoto, K., Orii, A., Pronost, G., Sekiya, H., Shiozawa, M., Sonoda, Y., Suzuki, Y., Takeda, A., Takemoto, Y., Takenaka, A., Tanaka, H., Watanabe, S., Yano, T., Han, S., Kajita, T., Okumura, K., Tashiro, T., Wang, R., Xia, J., Megias, G. D., Bravo-Berguño, D., Labarga, L., Marti, Ll., Zaldivar, B., Pointon, B. W., Blaszczyk, F. d. M., Kearns, E., Raaf, J. L., Stone, J. L., Wan, L., Wester, T., Bian, J., Griskevich, N. J., Kropp, W. R., Locke, S., Mine, S., Smy, M. B., Sobel, H. W., Takhistov, V., Weatherly, P., Hill, J., Kim, J. Y., Lim, I. T., Park, R. G., Bodur, B., Scholberg, K., Walter, C. W., Bernard, L., Coffani, A., Drapier, O., Hedri, S. El, Giampaolo, A., Gonin, M., Mueller, Th. A., Paganini, P., Quilain, B., Ishizuka, T., Nakamura, T., Jang, J. S., Learned, J. G., Anthony, L. H. V., Martin, D. G. R., Sztuc, A. A., Uchida, Y., Berardi, V., Catanesi, M. G., Radicioni, E., Calabria, N. F., Machado, L. N., De Rosa, G., Collazuol, G., Iacob, F., Lamoureux, M., Ospina, N., Ludovici, L., Maekawa, Y., Nishimura, Y., Cao, S., Friend, M., Hasegawa, T., Ishida, T., Jakkapu, M., Kobayashi, T., Matsubara, T., Nakadaira, T., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Kotsar, Y., Nakano, Y., Ozaki, H., Shiozawa, T., Suzuki, A. T., Takeuchi, Y., Yamamoto, S., Ali, A., Ashida, Y., Feng, J., Hirota, S., Kikawa, T., Mori, M., Nakaya, T., Wendell, R. A., Yasutome, K., Fernandez, P., McCauley, N., Mehta, P., Pritchard, A., Tsui, K. M., Fukuda, Y., Itow, Y., Menjo, H., Niwa, T., Sato, K., Tsukada, M., Mijakowski, P., Jiang, J., Jung, C. K., Vilela, C., Wilking, M. J., Yanagisawa, C., Hagiwara, K., Harada, M., Horai, T., Ishino, H., Ito, S., Koshio, Y., Kitagawa, H., Ma, W., Piplani, N., Sakai, S., Kuno, Y., Barr, G., Barrow, D., Cook, L., Goldsack, A., Samani, S., Simpson, C., Wark, D., Nova, F., Boschi, T., Di Lodovico, F., Migenda, J., Sedgwick, S. Molina, Taani, M., Zsoldos, S., Yang, J. Y., Jenkins, S. J., Malek, M., McElwee, J. M., Stone, O., Thiesse, M. D., Thompson, L. F., Okazawa, H., Kim, S. B., Yu, I., Nishijima, K., Koshiba, M., Nakajima, K. Iwamoto Y., Ogawa, N., Yokoyama, M., Martens, K., Vagins, M. R., Izumiyama, S., Kuze, M., Tanaka, M., Yoshida, T., Inomoto, M., Ishitsuka, M., Ito, H., Matsumoto, R., Ohta, K., Shinoki, M., Martin, J. F., Tanaka, H. A., Towstego, T., Akutsu, R., Hartz, M., Konaka, A., de Perio, P., Prouse, N. W., Chen, S., Xu, B. D., Posiadala-Zezula, M., Hadley, D., Richards, B., Jamieson, B., Walker, J., Minamino, A., Pintaudi, G., Sano, S., Sasaki, R., Ichikawa, A. K., and Nakamura, K. D.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics, High Energy Physics - Experiment
Abstract: The Super-Kamiokande detector can be used to search for neutrinos in time coincidence with gravitational waves detected by the LIGO-Virgo Collaboration (LVC). Both low-energy ($7-100$ MeV) and high-energy ($0.1-10^5$ GeV) samples were analyzed in order to cover a very wide neutrino spectrum. Follow-ups of 36 (out of 39) gravitational waves reported in the GWTC-2 catalog were examined; no significant excess above the background was observed, with 10 (24) observed neutrinos compared with 4.8 (25.0) expected events in the high-energy (low-energy) samples. A statistical approach was used to compute the significance of potential coincidences. For each observation, p-values were estimated using neutrino direction and LVC sky map ; the most significant event (GW190602_175927) is associated with a post-trial p-value of $7.8\%$ ($1.4\sigma$). Additionally, flux limits were computed independently for each sample and by combining the samples. The energy emitted as neutrinos by the identified gravitational wave sources was constrained, both for given flavors and for all-flavors assuming equipartition between the different flavors, independently for each trigger and by combining sources of the same nature., Comment: 16 pages, 5 figures. v2: adding corrections from The Astrophysical Journal review
Published: 2021
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32. Search for Tens of MeV Neutrinos associated with Gamma-Ray Bursts in Super-Kamiokande

Author: Collaboration, The Super-Kamiokande, Orii, A., Abe, K., Bronner, C., Hayato, Y., Ikeda, M., Imaizumi, S., Ito, H., Kameda, J., Kataoka, Y., Kato, Y., Kishimoto, Y., Miura, M., Moriyama, S., Mochizuki, T., Nagao, Y., Nakahata, M., Nakajima, Y., Nakayama, S., Okada, T., Okamoto, K., Pronost, G., Sekiya, H., Shiozawa, M., Sonoda, Y., Suzuki, Y., Takeda, A., Takemoto, Y., Takenaka, A., Tanaka, H., Yano, T., Han, S., Kajita, T., Okumura, K., Tashiro, T., Wang, R., Xia, J., Megias, G. D., Bravo-Berguno, D., Labarga, L., Marti, Ll., Zaldivar, B., Blaszczyk, F. d. M., Kearns, E., Raaf, J. L., Stone, J. L., Wan, L., Wester, T., Pointon, B. W., Bian, J., Griskevich, N. J., Kropp, W. R., Locke, S., Mine, S., Smy, M. B., Sobel, H. W., Takhistov, V., Weatherly, P., Ganezer, K. S., Hill, J., Kim, J. Y., Lim, I. T., Park, R. G., Bodur, B., Scholberg, K., Walter, C. W., Bernard, L., Coffani, A., Drapier, O., Hedri, S. El, Giampaolo, A., Gonin, M., Mueller, Th. A., Paganini, P., Quilain, B., Ishizuka, T., Nakamura, T., Jang, J. S., Learned, J. G., Matsuno, S., Anthony, L. H. V., Litchfield, R. P., Sztuc, A. A., Uchida, Y., Berardi, V., Catanesi, M. G., Radicioni, E., Calabria, N. F., Machado, L. N., De Rosa, G., Collazuol, G., Iacob, F., Lamoureux, M., Ospina, N., Ludovici, L., Nishimura, Y., Cao, S., Friend, M., Hasegawa, T., Ishida, T., Kobayashi, T., Jakkapu, M., Matsubara, T., Nakadaira, T., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Boschi, T., Di Lodovico, F., Sedgwick, S. Molina, Taani, M., Zsoldos, S., Hasegawa, M., Isobe, Y., Miyabe, H., Nakano, Y., Shiozawa, T., Sugimoto, T., Suzuki, A. T., Takeuchi, Y., Yamamoto, S., Ali, A., Ashida, Y., Feng, J., Hirota, S., Jiang, M., Ichikawa, A. K., Kikawa, T., Mori, M., Nakamura, KE., Nakaya, T., Wendell, R. A., Yasutome, K., Fernandez, P., McCauley, N., Mehta, P., Pritchard, A., Tsui, K. M., Fukuda, Y., Itow, Y., Menjo, H., Niwa, T., Sato, K., Tsukada, M., Mijakowski, P., Frankiewicz, K., Jung, C. K., Vilela, C., Wilking, M. J., Yanagisawa, C., Fukuda, D., Harada, M., Hagiwara, K., Horai, T., Ishino, H., Ito, S., Koshio, Y., Ma, W., Piplani, N., Sakai, S., Sakuda, M., Takahira, Y., Xu, C., Kuno, Y., Barr, G., Barrow, D., Cook, L., Goldsack, A., Samani, S., Simpson, C., Wark, D., Nova, F., Yang, J. Y., Jenkins, S. J., Malek, M., McElwee, J. M., Stone, O., Thiesse, M. D., Thompson, L. F., Okazawa, H., Choi, Y., Kim, S. B., Yu, I., Nishijima, K., Koshiba, M., Iwamoto, K., Ogawa, N., Yokoyama, M., Martens, K., Vagins, M. R., Izumiyama, S., Kuze, M., Tanaka, M., Yoshida, T., Inomoto, M., Ishitsuka, M., Matsumoto, R., Ohta, K., Shinoki, M., Martin, J. F., Nantais, C. M., Tanaka, H. A., Towstego, T., Akutsu, R., Hartz, M., Konaka, A., de Perio, P., Prouse, N. W., Chen, S., Xu, B. D., Posiadala-Zezula, M., Richards, B., Jamieson, B., Walker, J., Minamino, A., Pintaudi, G., and Sasaki, R.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, High Energy Physics - Experiment
Abstract: A search for neutrinos produced in coincidence with Gamma-Ray Bursts(GRB) was conducted with the Super-Kamiokande (SK) detector. Between December 2008 and March 2017, the Gamma-ray Coordinates Network recorded 2208 GRBs that occurred during normal SK operation. Several time windows around each GRB were used to search for coincident neutrino events. No statistically significant signal in excess of the estimated backgrounds was detected. The $\bar\nu_e$ fluence in the range from 8 MeV to 100 MeV in positron total energy for $\bar\nu_e+p\rightarrow e^{+}+n$ was found to be less than $\rm 5.07\times10^5$ cm$^{-2}$ per GRB in 90\% C.L. Upper bounds on the fluence as a function of neutrino energy were also obtained., Comment: 29 pages, 16 figures, 5 tables, accepted by PTEP
Published: 2021

33. Search for solar electron anti-neutrinos due to spin-flavor precession in the Sun with Super-Kamiokande-IV

Author: Collaboration, Super-Kamiokande, Abe, K., Bronner, C., Hayato, Y., Ikeda, M., Imaizumi, S., Ito, H., Kameda, J., Kataoka, Y., Miura, M., Moriyama, S., Nagao, Y., Nakahata, M., Nakajima, Y., Nakayama, S., Okada, T., Okamoto, K., Orii, A., Pronost, G., Sekiya, H., Shiozawa, M., Sonoda, Y., Suzuki, Y., Takeda, A., Takemoto, Y., Takenaka, A., Tanaka, H., Yano, T., Akutsu, R., Han, S., Kajita, T., Okumura, K., Tashiro, T., Wang, R., Xia, J., Bravo-Berguño, D., Labarga, L., Marti, Ll., Zaldivar, B., Blaszczyk, F. d. M., Kearns, E., Raaf, J. L., Stone, J. L., Wan, L., Wester, T., Pointin, B. W., Bian, J., Griskevich, N. J., Kropp, W. R., Locke, S., Mine, S., Smy, M. B., Sobel, H. W., Takhistov, V., Weatherly, P., Hill, J., Kim, J. Y., Lim, I. T., Park, R. G., Bodur, B., Scholberg, K., Walter, C. W., Bernard, L., Coffani, A., Drapier, O., Hedri, S. El, Giampaolo, A., Gonin, M., Mueller, Th. A., Paganini, P., Quilain, B., Ishizuka, T., Nakamura, T., Jang, J. S., Learned, J. G., Anthony, L. H. V., Sztuc, A. A., Uchida, Y., Berardi, V., Catanesi, M. G., Radicioni, E., Calabria, N. F., Machado, L. N., De Rosa, G., Collazuol, G., Iacob, F., Lamoureux, M., Ospina, N., Ludovici, L., Nishimura, Y., Cao, S., Friend, M., Hasegawa, T., Ishida, T., Jakkapu, M., Kobayashi, T., Matsubara, T., Nakadaira, T., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Nakano, Y., Shiozawa, T., Suzuki, A. T., Takeuchi, Y., Yamamoto, S., Ali, A., Ashida, Y., Feng, J., Hirota, S., Ichikawa, A. K., Kikawa, T., Mori, M., Nakaya, T., Wendell, R. A., Yasutome, Y., Fernandez, P., McCauley, N., Mehta, P., Pritchard, A., Tsui, K. M., Fukuda, Y., Itow, Y., Menjo, H., Niwa, T., Sato, K., Tsukada, M., Mijakowski, P., Jung, C. K., Vilela, C., Wilking, M. J., Yanagisawa, C., Harada, M., Hagiwara, K., Horai, T., Ishino, H., Ito, S., Koshio, Y., Ma, W., Piplani, N., Sakai, S., Kuno, Y., Barr, G., Barrow, D., Cook, L., Goldsack, A., Samani, S., Simpson, C., Wark, D., Nova, F., Boschi, T., Di Lodovico, F., Taani, M., Migenda, J., Sedgwick, S. Molina, Zsoldos, S., Yang, J. Y., Jenkins, S. J., Malek, M., McElwee, J. M., Stone, O., Thiesse, M. D., Thompson, L. F., Okazawa, H., Kim, S. B., Yu, I., Nishijima, K., Koshiba, M., Iwamoto, K., Ogawa, N., Yokoyama, M., Martens, K., Vagins, M. R., Izumiyama, S., Kuze, M., Tanaka, M., Yoshida, T., Inomoto, M., Ishitsuka, M., Matsumoto, R., Ohta, K., Shinoki, M., Martin, J. F., Tanaka, H. A., Towstego, T., Hartz, M., Konaka, A., de Perio, P., Prouse, N. W., Chen, S., Xu, B. D., Richards, B., Jamieson, B., Walker, J., Minamino, A., Pintaudi, G., Sasaki, R., and Posiadala-Zezula, M.
Subjects: High Energy Physics - Experiment, Physics - Instrumentation and Detectors
Abstract: Due to a very low production rate of electron anti-neutrinos ($\bar{\nu}_e$) via nuclear fusion in the Sun, a flux of solar $\bar{\nu}_e$ is unexpected. An appearance of $\bar{\nu}_e$ in solar neutrino flux opens a new window for the new physics beyond the standard model. In particular, a spin-flavor precession process is expected to convert an electron neutrino into an electron anti-neutrino (${\nu_e\to\bar{\nu}_e}$) when neutrino has a finite magnetic moment. In this work, we have searched for solar $\bar{\nu}_e$ in the Super-Kamiokande experiment, using neutron tagging to identify their inverse beta decay signature. We identified 78 $\bar{\nu}_e$ candidates for neutrino energies of 9.3 to 17.3 MeV in 2970.1 live days with a fiducial volume of 22.5 kiloton water (183.0 kton$\cdot$year exposure). The energy spectrum has been consistent with background predictions and we thus derived a 90% confidence level upper limit of ${4.7\times10^{-4}}$ on the $\nu_e\to\bar{\nu}_e$ conversion probability in the Sun. We used this result to evaluate the sensitivity of future experiments, notably the Super-Kamiokande Gadolinium (SK-Gd) upgrade., Comment: 16 pages, 10 figures, 7 tables
Published: 2020
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34. Neutron-Antineutron Oscillation Search using a 0.37 Megaton$\cdot$Year Exposure of Super-Kamiokande

Author: Collaboration, Super-Kamiokande, Abe, K., Bronner, C., Hayato, Y., Ikeda, M., Imaizumi, S., Ito, H., Kameda, J., Kataoka, Y., Miura, M., Moriyama, S., Nagao, Y., Nakahata, M., Nakajima, Y., Nakayama, S., Okada, T., Okamoto, K., Orii, A., Pronost, G., Sekiya, H., Shiozawa, M., Sonoda, Y., Suzuki, Y., Takeda, A., Takemoto, Y., Takenaka, A., Tanaka, H., Yano, T., Akutsu, R., Han, S., Kajita, T., Okumura, K., Tashiro, T., Wang, R., Xia, J., Bravo-Berguño, D., Labarga, L., Marti, Ll., Zaldivar, B., Blaszczyk, F. d. M., Kearns, E., Gustafson, J. D., Raaf, J. L., Stone, J. L., Wan, L., Wester, T., Bian, J., Griskevich, N. J., Kropp, W. R., Locke, S., Mine, S., Smy, M. B., Sobel, H. W., Takhistov, V., Weatherly, P., Hill, J., Kim, J. Y., Lim, I. T., Park, R. G., Bodur, B., Scholberg, K., Walter, C. W., Coffani, A., Drapier, O., Hedri, S. El, Giampaolo, A., Gonin, M., Mueller, Th. A., Paganini, P., Quilain, B., Ishizuka, T., Nakamura, T., Jang, J. S., Learned, J. G., Anthony, L. H. V., Sztuc, A. A., Uchida, Y., Berardi, V., Catanesi, M. G., Radicioni, E., Calabria, N. F., Machado, L. N., De Rosa, G., Collazuol, G., Iacob, F., Lamoureux, M., Ospina, N., Ludovici, L., Nishimura, Y., Cao, S., Friend, M., Hasegawa, T., Ishida, T., Kobayashi, T., Matsubara, T., Nakadaira, T., Jakkapu, M., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Nakano, Y., Shiozawa, T., Suzuki, A. T., Takeuchi, Y., Yamamoto, S., Ali, A., Ashida, Y., Feng, J., Hirota, S., Ichikawa, A. K., Kikawa, T., Mori, M., Nakaya, T., Wendell, R. A., Yasutome, K., Fernandez, P., McCauley, N., Mehta, P., Pritchard, A., Tsui, K. M., Fukuda, Y., Itow, Y., Menjo, H., Niwa, T., Sato, K., Tsukada, M., Mijakowski, P., Posiadala-Zezula, M., Jung, C. K., Vilela, C., Wilking, M. J., Yanagisawa, C., Harada, M., Hagiwara, K., Horai, T., Ishino, H., Ito, S., Koshio, Y., Ma, W., Piplani, N., Sakai, S., Kuno, Y., Barr, G., Barrow, D., Cook, L., Goldsack, A., Samani, S., Simpson, C., Wark, D., Nova, F., Boschi, T., Di Lodovico, F., Sedgwick, S. Molina, Taani, M., Zsoldos, S., Yang, J. Y., Jenkins, S. J., McElwee, J. M., Thiesse, M. D., Thompson, L. F., Malek, M., Stone, O., Okazawa, H., Kim, S. B., Yu, I., Nishijima, K., Koshiba, M., Ogawa, N., Iwamoto, K., Yokoyama, M., Martens, K., Vagins, M. R., Kuze, M., Izumiyama, S., Tanaka, M., Yoshida, T., Inomoto, M., Ishitsuka, M., Matsumoto, R., Ohta, K., Shinoki, M., Martin, J. F., Tanaka, H. A., Towstego, T., Hartz, M., Konaka, A., de Perio, P., Prouse, N. W., Pointon, B. W., Chen, S., Xu, B. D., Richards, B., Jamieson, B., Walker, J., Minamino, A., Pintaudi, G., and Sasaki, R.
Subjects: High Energy Physics - Experiment
Abstract: As a baryon number violating process with $\Delta B=2$, neutron-antineutron oscillation ($n\to\bar n$) provides a unique test of baryon number conservation. We have performed a search for $n\to\bar n$ oscillation with bound neutrons in Super-Kamiokande, with the full data set from its first four run periods, representing an exposure of 0.37~Mton-years. The search used a multivariate analysis trained on simulated $n\to\bar n$ events and atmospheric neutrino backgrounds and resulted in 11 candidate events with an expected background of 9.3 events. In the absence of statistically significant excess, we derived a lower limit on $\bar n$ appearance lifetime in $^{16}$O nuclei of $3.6\times{10}^{32}$ years and on the neutron-antineutron oscillation time of $\tau_{n\to\bar n} > 4.7\times10^{8}$~s at 90\% C.L..
Published: 2020
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35. Search for proton decay via $p\to e^+\pi^0$ and $p\to \mu^+\pi^0$ with an enlarged fiducial volume in Super-Kamiokande I-IV

Author: Collaboration, Super-Kamiokande, Takenaka, A., Abe, K., Bronner, C., Hayato, Y., Ikeda, M., Imaizumi, S., Ito, H., Kameda, J., Kataoka, Y., Kato, Y., Kishimoto, Y., Marti, Ll., Miura, M., Moriyama, S., Mochizuki, T., Nagao, Y., Nakahata, M., Nakajima, Y., Nakayama, S., Okada, T., Okamoto, K., Orii, A., Pronost, G., Sekiya, H., Shiozawa, M., Sonoda, Y., Suzuki, Y., Takeda, A., Takemoto, Y., Tanaka, H., Yano, T., Akutsu, R., Han, S., Kajita, T., Okumura, K., Tashiro, T., Wang, R., Xia, J., Bravo-Berguno, D., Labarga, L., Fernandez, P., Zaldivar, B., Blaszczyk, F. d. M., Kearns, E., Raaf, J. L., Stone, J. L., Wan, L., Wester, T., Pointon, B. W., Bian, J., Griskevich, N. J., Kropp, W. R., Locke, S., Mine, S., Smy, M. B., Sobel, H. W., Takhistov, V., Weatherly, P., Ganezer, K. S., Hill, J., Kim, J. Y., Lim, I. T., Park, R. G., Bodur, B., Scholberg, K., Walter, C. W., Coffani, A., Drapier, O., Hedri, S. El, Giampaolo, A., Gonin, M., Mueller, Th. A., Paganini, P., Quilain, B., Ishizuka, T., Nakamura, T., Jang, J. S., Learned, J. G., Matsuno, S., Anthony, L. H. V., Litchfield, R. P., Sztuc, A. A., Uchida, Y., Berardi, V., Catanesi, M. G., Radicioni, E., Calabria, N. F., Machado, L. N., De Rosa, G., Collazuol, G., Iacob, F., Lamoureux, M., Ospina, N., Ludovici, L., Nishimura, Y., Cao, S., Friend, M., Hasegawa, T., Ishida, T., Jakkapu, M., Kobayashi, T., Matsubara, T., Nakadaira, T., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Hasegawa, M., Isobe, Y., Miyabe, H., Nakano, Y., Shiozawa, T., Sugimoto, T., Suzuki, A. T., Takeuchi, Y., Yamamoto, S., Ali, A., Ashida, Y., Feng, J., Hirota, S., Ichikawa, A. K., Jiang, M., Kikawa, T., Mori, M., Nakamura, KE., Nakaya, T., Wendell, R. A., Yasutome, K., McCauley, N., Mehta, P., Pritchard, A., Tsui, K. M., Fukuda, Y., Itow, Y., Menjo, H., Niwa, T., Sato, K., Taani, M., Tsukada, M., Mijakowski, P., Frankiewicz, K., Jung, C. K., Santucci, G., Vilela, C., Wilking, M. J., Yanagisawa, C., Fukuda, D., Harada, M., Hagiwara, K., Horai, T., Ishino, H., Ito, S., Koshio, Y., Ma, W., Piplani, N., Sakai, S., Sakuda, M., Takahira, Y., Xu, C., Kuno, Y., Barr, G., Barrow, D., Cook, L., Simpson, C., Wark, D., Nova, F., Boschi, T., Di Lodovico, F., Sedgwick, S. Molina, Zsoldos, S., Yang, J. Y., Jenkins, S. J., McElwee, J. M., Thiesse, M. D., Thompson, L. F., Okazawa, H., Choi, Y., Kim, S. B., Yu, I., Nishijima, K., Koshiba, M., Iwamoto, K., Ogawa, N., Yokoyama, M., Goldsack, A., Martens, K., Vagins, M. R., Kuze, M., Tanaka, M., Yoshida, T., Inomoto, M., Ishitsuka, M., Matsumoto, R., Ohta, K., Shinoki, M., Martin, J. F., Nantais, C. M., Tanaka, H. A., Towstego, T., Hartz, M., Konaka, A., de Perio, P., Prouse, N. W., Chen, S., Xu, B. D., Posiadala-Zezula, M., Richards, B., Jamieson, B., Walker, J., Minamino, A., Pintaudi, G., and Sasaki, R.
Subjects: High Energy Physics - Experiment
Abstract: We have searched for proton decay via $p\to e^+\pi^0$ and $p\to \mu^+\pi^0$ modes with the enlarged fiducial volume data of Super-Kamiokande from April 1996 to May 2018, which corresponds to 450 kton$\cdot$years exposure. We have accumulated about 25% more livetime and enlarged the fiducial volume of the Super-Kamiokande detector from 22.5 kton to 27.2 kton for this analysis, so that 144 kton$\cdot$years of data, including 78 kton$\cdot$years of additional fiducial volume data, has been newly analyzed. No candidates have been found for $p\to e^+\pi^0$ and one candidate remains for $p\to \mu^+\pi^0$ in the conventional 22.5 kton fiducial volume and it is consistent with the atmospheric neutrino background prediction. We set lower limits on the partial lifetime for each of these modes: $\tau/B(p\to e^+\pi^0) > 2.4 \times 10^{34}$ years and $\tau/B(p\to \mu^+\pi^0) > 1.6 \times 10^{34}$ years at 90% confidence level., Comment: 16 pages, 10 figures
Published: 2020
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36. Indirect Search for Dark Matter from the Galactic Center and Halo with the Super-Kamiokande Detector

Author: Collaboration, Super-Kamiokande, Abe, K., Bronner, C., Haga, Y., Hayato, Y., Ikeda, M., Imaizumi, S., Ito, H., Iyogi, K., Kameda, J., Kataoka, Y., Kato, Y., Kishimoto, Y., Marti, Ll., Miura, M., Moriyama, S., Mochizuki, T., Nagao, Y., Nakahata, M., Nakajima, Y., Nakajima, T., Nakayama, S., Okada, T., Okamoto, K., Orii, A., Pronost, G., Sekiya, H., Shiozawa, M., Sonoda, Y., Takeda, A., Takenaka, A., Tanaka, H., Tasaka, S., Tomura, T., Ueno, K., Yano, T., Yokozawa, T., Akutsu, R., Han, S., Irvine, T., Kajita, T., Kametani, I., Lee, K. P., McLachlan, T., Okumura, K., Richard, E., Tashiro, T., Wang, R., Xia, J., Bravo-Berguño, D., Labarga, L., Fernandez, P., Blaszczyk, F. d. M., Gustafson, J., Kachulis, C., Kearns, E., Raaf, J. L., Stone, J. L., Sulak, L. R., Sussman, S., Wan, L., Wester, T., Berkman, S., Tobayama, S., Bian, J., Carminati, G., Elnimr, M., Griskevich, N. J., Kropp, W. R., Locke, S., Mine, S., Renshaw, A., Smy, M. B., Sobel, H. W., Takhistov, V., Weatherly, P., Hartfiel, B. L., Hill, J., Keig, W. E., Hong, N., Kim, J. Y., Lim, I. T., Park, R. G., Akiri, T., Bodur, B., Himmel, A., Li, Z., O'Sullivan, E., Scholberg, K., Walter, C. W., Wongjirad, T., Coffani, A., Drapier, O., Hedri, S. El, Giampaolo, A., Gonin, M., Imber, J., Mueller, Th. A., Paganini, P., Quilain, B., Ishizuka, T., Nakamura, T., Jang, J. S., Choi, K., Learned, J. G., Matsuno, S., Smith, S. N., Amey, J., Anthony, L. H. V., Litchfield, R. P., Ma, W. Y., Sztuc, A. A., Uchida, Y., Wascko, M. O., Berardi, V., Catanesi, M. G., Intonti, R. A., Radicioni, E., Calabria, N. F., Machado, L. N., De Rosa, G., Collazuol, G., Iacob, F., Lamoureux, M., Ospina, N., Ludovici, L., Boschi, T., Di Lodovico, F., Sedgwick, S. Molina, Zsoldos, S., Nishimura, Y., Cao, S., Friend, M., Hasegawa, T., Ishida, T., Ishii, T., Kobayashi, T., Nakadaira, T., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Abe, KE., Hasegawa, M., Isobe, Y., Miyabe, H., Nakano, Y., Shiozawa, T., Sugimoto, T., Suzuki, A. T., Takeuchi, Y., Yamamoto, S., Ali, A., Ashida, Y., Hayashino, T., Hiraki, T., Hirota, S., Huang, K., Ieki, K., Jiang, M., Kikawa, T., Mori, M., Murakami, A., Nakamura, KE., Nakaya, T., Patel, N. D., Suzuki, K., Takahashi, S., Tateishi, K., Wendell, R. A., McCauley, N., Mehta, P., Pritchard, A., Tsui, K. M., Fukuda, Y., Itow, Y., Menjo, H., Mitsuka, G., Murase, M., Muto, F., Niwa, T., Sato, K., Suzuki, T., Taani, M., Tsukada, z M., Mijakowski, P., Frankiewicz, K., Hignight, J., Jung, C. K., Li, X., Palomino, J. L., Santucci, G., Vilela, C., Wilking, M. J., Yanagisawa, C., Fukuda, D., Hagiwara, K., Harada, M., Horai, T., Ishino, H., Ito, S., Kayano, T., Kibayashi, A., Koshio, Y., Ma, W., Mori, T., Nagata, H., Piplani, N., Sakuda, M., Seiya, S., Takahira, Y., Xu, C., Yamaguchi, R., Kuno, Y., Barr, G., Barrow, D., Cook, L., Simpson, C., Wark, D., Nova, F., Tacik, R., Yang, J. Y., Cole, A., Jenkins, S. J., McElwee, J., Thiesse, M., Thompson, L., Okazawa, H., Kim, S. B., Choi, Y., Ito, K., Nishijima, K., Iwamoto, K., Koshiba, M., Suda, Y., Yokoyama, M., Calland, R. G., Goldsack, A., Martens, K., Murdoch, M., Suzuki, Y., Vagins, M. R., Hamabe, D., Kuze, M., Okajima, Y., Tanaka, M., Yoshida, T., Inomoto, M., Ishitsuka, M., Matsumoto, R., Ohta, K., Shinoki, M., Martin, J. F., Nantais, C. M., Tanaka, H. A., Towstego, T., Hartz, M., Konaka, A., de Perio, P., Prouse, N. W., Chen, S., Xu, B. D., Zhang, Y., Richards, B., Connolly, K., Wilkes, R. J., Jamieson, B., Walker, J., Giorgio, P., Minamino, A., and Pintaudi, G.
Subjects: High Energy Physics - Experiment
Abstract: We present a search for an excess of neutrino interactions due to dark matter in the form of Weakly Interacting Massive Particles (WIMPs) annihilating in the galactic center or halo based on the data set of Super-Kamiokande-I, -II, -III and -IV taken from 1996 to 2016. We model the neutrino flux, energy, and flavor distributions assuming WIMP self-annihilation is dominant to $\nu \overline{\nu}$, $\mu^+\mu^-$, $b\overline{b}$, or $W^+W^-$. The excess is in comparison to atmospheric neutrino interactions which are modeled in detail and fit to data. Limits on the self-annihilation cross section $\langle \sigma_{A} V \rangle$ are derived for WIMP masses in the range 1 GeV to 10 TeV, reaching as low as $9.6 \times10^{-23}$ cm$^3$ s$^{-1}$ for 5 GeV WIMPs in $b\bar b$ mode and $1.2 \times10^{-24}$ cm$^3$ s$^{-1}$ for 1 GeV WIMPs in $\nu \bar \nu$ mode. The obtained sensitivity of the Super-Kamiokande detector to WIMP masses below several tens of GeV is the best among similar indirect searches to date., Comment: 13 pages, 12 figures, Submitted to Phys. Rev. D
Published: 2020
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37. Search for proton decay into three charged leptons in 0.37 megaton-years exposure of the Super-Kamiokande

Author: Collaboration, Super-Kamiokande, Tanaka, M., Abe, K., Bronner, C., Hayato, Y., Ikeda, M., Imaizumi, S., Ito, H., Kameda, J., Kataoka, Y., Kato, Y., Kishimoto, Y., Marti, Ll., Miura, M., Moriyama, S., Mochizuki, T., Nakahata, M., Nakajima, Y., Nakayama, S., Okada, T., Okamoto, K., Orii, A., Pronost, G., Sekiya, H., Shiozawa, M., Sonoda, Y., Takeda, A., Takenaka, A., Tanaka, H., Yano, T., Akutsu, R., Kajita, T., Okumura, K., Wang, R., Xia, J., Bravo-Berguño, D., Labarga, L., Fernandez, P., Blaszczyk, F. d. M., Kearns, E., Raaf, J. L., Stone, J. L., Wan, L., Wester, T., Bian, J., Griskevich, N. J., Kropp, W. R., Locke, S., Mine, S., Smy, M. B., Sobel, H. W., Takhistov, V., Weatherly, P., Hill, J., Kim, J. Y., Lim, I. T., Park, R. G., Bodur, B., Scholberg, K., Walter, C. W., Coffani, A., Drapier, O., Hedri, S. El, Gonin, M., Mueller, Th. A., Paganini, P., Ishizuka, T., Nakamura, T., Jang, J. S., Learned, J. G., Matsuno, S., Litchfield, R. P., Sztuc, A. A., Uchida, Y., Berardi, V., Catanesi, M. G., Radicioni, E., Calabria, N. F., De Rosa, G., Collazuol, G., Iacob, F., Ludovici, L., Nishimura, Y., Cao, S., Friend, M., Hasegawa, T., Ishida, T., Kobayashi, T., Nakadaira, T., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Hasegawa, M., Isobe, Y., Miyabe, H., Nakano, Y., Shiozawa, T., Sugimoto, T., Suzuki, A. T., Takeuchi, Y., Ali, A., Ashida, Y., Hirota, S., Jiang, M., Kikawa, T., Mori, M., Nakamura, KE., Nakaya, T., Wendell, R. A., Anthony, L. H. V., McCauley, N., Mehta, P., Pritchard, A., Tsui, K. M., Fukuda, Y., Itow, Y., Niwa, T., Taani, M., Tsukada, M., Mijakowski, P., Frankiewicz, K., Jung, C. K., Vilela, C., Wilking, M. J., Yanagisawa, C., Fukuda, D., Harada, M., Hagiwara, K., Horai, T., Ishino, H., Ito, S., Koshio, Y., Sakuda, M., Takahira, Y., Xu, C., Kuno, Y., Barrow, D., Cook, L., Simpson, C., Wark, D., Nova, F., Boschi, T., Di Lodovico, F., Sedgwick, S. Molina, Zsoldos, S., Kim, S. B., Yang, J. Y., Thiesse, M., Thompson, L., Okazawa, H., Choi, Y., Nishijima, K., Koshiba, M., Yokoyama, M., Goldsack, A., Martens, K., Quilain, B., Suzuki, Y., Vagins, M. R., Kuze, M., Yoshida, T., Ishitsuka, M., Matsumoto, R., Ohta, K., Martin, J. F., Nantais, C. M., Tanaka, H. A., Towstego, T., Hartz, M., Konaka, A., de Perio, P., Prouse, N. W., Chen, S., Xu, B. D., Richards, B., Jamieson, B., Walker, J., Minamino, A., and Pintaudi, G.
Subjects: High Energy Physics - Experiment
Abstract: A search for proton decay into three charged leptons has been performed by using 0.37$\,$Mton$\cdot$years of data collected in Super-Kamiokande. All possible combinations of electrons, muons and their anti-particles consistent with charge conservation were considered as decay modes. No significant excess of events has been found over the background, and lower limits on the proton lifetime divided by the branching ratio have been obtained. The limits range between $9.2\times10^{33}$ to $3.4\times10^{34}$ years at 90$\,$% confidence level, improving by more than an order of magnitude upon limits from previous experiments. A first limit has been set for the $p\rightarrow\mu^-e^+e^+$ mode.
Published: 2020
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38. Search for Astronomical Neutrinos from Blazar TXS0506+056 in Super-Kamiokande

Author: Hagiwara, K., Abe, K., Bronner, C., Hayato, Y., Ikeda, M., Ito, H., Kameda, J., Kataoka, Y., Kato, Y., Kishimoto, Y., Marti, Ll., Miura, M., Moriyama, S., Mochizuki, T., Nakahata, M., Nakajima, Y., Nakayama, S., Okada, T., Okamoto, K., Orii, A., Pronost, G., Sekiya, H., Shiozawa, M., Sonoda, Y., Takeda, A., Takenaka, A., Tanaka, H., Yano, T., Akutsu, R., Kajita, T., Okumura, K., Wang, R., Xia, J., Bravo-Berguno, D., Labarga, L., Fernandez, P., Blaszczyk, F. d. M., Kearns, E., Raaf, J. L., Stone, J. L., Wan, L., Wester, T., Bian, J., Griskevich, N. J., Kropp, W. R., Locke, S., Mine, S., Smy, M. B., Sobel, H. W., Takhistov, V., Weatherly, P., Ganezer, K. S., Hill, J., Kim, J. Y., Lim, I. T., Park, R. G., Bodur, B., Scholberg, K., Walter, C. W., Coffani, A., Drapier, O., Gonin, M., Mueller, Th. A., Paganini, P., Ishizuka, T., Nakamura, T., Jang, J. S., Learned, J. G., Matsuno, S., Litchfield, R. P., Sztuc, A. A., Uchida, Y., Berardi, V., Calabria, N. F., Catanesi, M. G., Radicioni, E., De Rosa, G., Collazuol, G., Iacob, F., Ludovici, L., Nishimura, Y., Cao, S., Friend, M., Hasegawa, T., Ishida, T., Kobayashi, T., Nakadaira, T., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Hasegawa, M., Isobe, Y., Miyabe, H., Nakano, Y., Shiozawa, T., Sugimoto, T., Suzuki, A. T., Takeuchi, Y., Ali, A., Ashida, Y., Hirota, S., Jiang, M., Kikawa, T., Mori, M., Nakamura, KE., Nakaya, T., Wendell, R. A., Anthony, L. H. V., McCauley, N., Pritchard, A., Tsui, K. M., Fukuda, Y., Itow, Y., Niwa, T., Taani, M., Tsukada, M., Mijakowski, P., Frankiewicz, K., Jung, C. K., Vilela, C., Wilking, M. J., Yanagisawa, C., Fukuda, D., Harada, M., Horai, T., Ishino, H., Ito, S., Koshio, Y., Sakuda, M., Takahira, Y., Xu, C., Kuno, Y., Cook, L., Simpson, C., Wark, D., Di Lodovico, F., Sedgwick, S. Molina, Richards, B., Zsoldos, S., Kim, S. B., Thiesse, M., Thompson, L., Okazawa, H., Choi, Y., Nishijima, K., Koshiba, M., Yokoyama, M., Goldsack, A., Martens, K., Quilain, B., Suzuki, Y., Vagins, M. R., Kuze, M., Tanaka, M., Yoshida, T., Ishitsuka, M., Matsumoto, R., Ohta, K., Martin, J. F., Nantais, C. M., Tanaka, H. A., Towstego, T., Hartz, M., Konaka, A., de Perio, P., Chen, S., Jamieson, B., Walker, J., Minamino, A., and Pintaudi, G.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: We report a search for astronomical neutrinos in the energy region from several GeV to TeV in the direction of the blazar TXS0506+056 using the Super-Kamiokande detector following the detection of a 100 TeV neutrino from the same location by the IceCube collaboration. Using Super-Kamiokande neutrino data across several data samples observed from April 1996 to February 2018 we have searched for both a total excess above known backgrounds across the entire period as well as localized excesses on smaller time scales in that interval. No significant excess nor significant variation in the observed event rate are found in the blazar direction. Upper limits are placed on the electron and muon neutrino fluxes at 90\% confidence level as $6.03 \times 10^{-7}$ and $4.52 \times 10^{-7}$ to $9.26 \times 10^{-10}$ [${\rm erg}/{\rm cm}^2/{\rm s}$], respectively.
Published: 2019
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39. Sensitivity of Super-Kamiokande with Gadolinium to Low Energy Anti-neutrinos from Pre-supernova Emission

Author: Simpson, C., Abe, K., Bronner, C., Hayato, Y., Ikeda, M., Ito, H., Iyogi, K., Kameda, J., Kataoka, Y., Kato, Y., Kishimoto, Y., Marti, Ll., Miura, M., Moriyama, S., Mochizuki, T., Nakahata, M., Nakajima, Y., Nakayama, S., Okada, T., Okamoto, K., Orii, A., Pronost, G., Sekiya, H., Shiozawa, M., Sonoda, Y., Takeda, A., Takenaka, A., Tanaka, H., Yano, T., Akutsu, R., Kajita, T., Okumura, K., Wang, R., Xia, J., Bravo-Berguño, D., Labarga, L., Fernandez, P., Blaszczyk, F. d. M., Kachulis, C., Kearns, E., Raaf, J. L., Stone, J. L., Wan, L., Wester, T., Sussman, S., Berkman, S., Bian, J., Griskevich, N. J., Kropp, W. R., Locke, S., Mine, S., Smy, M. B., Sobel, H. W., Takhistov, V., Weatherly, P., Ganezer, K. S., Hill, J., Kim, J. Y., Lim, I. T., Park, R. G., Bodur, B., Scholberg, K., Walter, C. W., Coffani, A., Drapier, O., Gonin, M., Imber, J., Mueller, Th. A., Paganini, P., Ishizuka, T., Nakamura, T., Jang, J. S., Choi, K., Learned, J. G., Matsuno, S., Litchfield, R. P., Sztuc, A. A., Uchida, Y., Wascko, M. O., Berardi, V., Calabria, N. F., Catanesi, M. G., Intonti, R. A., Radicioni, E., De Rosa, G., Collazuol, G., Iacob, F., Ludovici, L., Nishimura, Y., Cao, S., Friend, M., Hasegawa, T., Ishida, T., Kobayashi, T., Nakadaira, T., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Abe, KE., Hasegawa, M., Isobe, Y., Miyabe, H., Nakano, Y., Shiozawa, T., Sugimoto, T., Suzuki, A. T., Takeuchi, Y., Ali, A., Ashida, Y., Hayashino, T., Hirota, S., Jiang, M., Kikawa, T., Mori, M., Nakamura, KE., Nakaya, T., Wendell, R. A., Anthony, L. H. V., McCauley, N., Pritchard, A., Tsui, K. M., Fukuda, Y., Itow, Y., Murrase, M., Niwa, T., Taani, M., Tsukada, M., Mijakowski, P., Frankiewicz, K., Jung, C. K., Li, X., Palomino, J. L., Santucci, G., Vilela, C., Wilking, M. J., Yanagisawa, C., Fukuda, D., Harada, M., Hagiwara, K., Horai, T., Ishino, H., Ito, S., Koshio, Y., Sakuda, M., Takahira, Y., Xu, C., Kuno, Y., Cook, L., Wark, D., Di Lodovico, F., Sedgwick, S. Molina, Richards, B., Zsoldos, S., Kim, S. B., Tacik, R., Thiesse, M., Thompson, L., Okazawa, H., Choi, Y., Nishijima, K., Koshiba, M., Yokoyama, M., Goldsack, A., Martens, K., Murdoch, M., Quilain, B., Suzuki, Y., Vagins, M. R., Kuze, M., Okajima, Y., Tanaka, M., Yoshida, T., Ishitsuka, M., Matsumoto, R., Ohta, K., Martin, J. F., Nantais, C. M., Tanaka, H. A., Towstego, T., Hartz, M., Konaka, A., de Perio, P., Chen, S., Jamieson, B., Walker, J., Minamino, A., and Pintaudi, G.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Supernova detection is a major objective of the Super-Kamiokande (SK) experiment. In the next stage of SK (SK-Gd), gadolinium (Gd) sulfate will be added to the detector, which will improve the ability of the detector to identify neutrons. A core-collapse supernova will be preceded by an increasing flux of neutrinos and anti-neutrinos, from thermal and weak nuclear processes in the star, over a timescale of hours; some of which may be detected at SK-Gd. This could provide an early warning of an imminent core-collapse supernova, hours earlier than the detection of the neutrinos from core collapse. Electron anti-neutrino detection will rely on inverse beta decay events below the usual analysis energy threshold of SK, so Gd loading is vital to reduce backgrounds while maximising detection efficiency. Assuming normal neutrino mass ordering, more than 200 events could be detected in the final 12 hours before core collapse for a 15-25 solar mass star at around 200 pc, which is representative of the nearest red supergiant to Earth, $\mathrm{\alpha}$Ori (Betelgeuse). At a statistical false alarm rate of 1 per century, detection could be up to 10 hours before core collapse, and a pre-supernova star could be detected by SK-Gd up to 600 pc away. A pre-supernova alert could be provided to the astrophysics community following gadolinium loading., Comment: 20 pages, 12 figures. Accepted by The Astrophysical Journal
Published: 2019
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40. Measurement of neutrino-oxygen neutral-current quasi-elastic cross section using atmospheric neutrinos at Super-Kamiokande

Author: Collaboration, Super-Kamiokande, Wan, L., Abe, K., Bronner, C., Hayato, Y., Ikeda, M., Iyogi, K., Kameda, J., Kato, Y., Kishimoto, Y., Marti, Ll., Miura, M., Moriyama, S., Mochizuki, T., Nakahata, M., Nakajima, Y., Nakano, Y., Nakayama, S., Okada, T., Okamoto, K., Orii, A., Pronost, G., Sekiya, H., Shiozawa, M., Sonoda, Y., Takeda, A., Takenaka, A., Tanaka, H., Yano, T., Akutsu, R., Kajita, T., Nishimura, Y., Okumura, K., Wang, R., Xia, J., Labarga, L., Fernandez, P., Blaszczyk, F. d. M., Kachulis, C., Kearns, E., Raaf, J. L., Stone, J. L., Sussman, S., Berkman, S., Bian, J., Griskevich, N. J., Kropp, W. R., Locke, S., Mine, S., Weatherly, P., Smy, M. B., Sobel, H. W., Takhistov, V., Ganezer, K. S., Hill, J., Kim, J. Y., Lim, I. T., Park, R. G., Bodur, B., Scholberg, K., Walter, C. W., Gonin, M., Imber, J., Mueller, Th. A., Ishizuka, T., Nakamura, T., Jang, J. S., Choi, K., Learned, J. G., Matsuno, S., Litchfield, R. P., Uchida, Y., Wascko, M. O., Calabria, N. F., Catanesi, M. G., Intonti, R. A., Radicioni, E., De Rosa, G., Ali, A., Collazuol, G., Iacob, F., Ludovici, L., Cao, S., Friend, M., Hasegawa, T., Ishida, T., Kobayashi, T., Nakadaira, T., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Abe, KE., Hasegawa, M., Isobe, Y., Miyabe, H., Sugimoto, T., Suzuki, A. T., Takeuchi, Y., Ashida, Y., Hayashino, T., Hirota, S., Jiang, M., Kikawa, T., Mori, M., Nakamura, KE., Nakaya, T., Wendell, R. A., Anthony, L. H. V., McCauley, N., Pritchard, A., Tsui, K. M., Fukuda, Y., Itow, Y., Murrase, M., Mijakowski, P., Frankiewicz, K., Jung, C. K., Li, X., Palomino, J. L., Santucci, G., Vilela, C., Wilking, M. J., Yanagisawa, C., Fukuda, D., Hagiwara, K., Ishino, H., Ito, S., Koshio, Y., Sakuda, M., Takahira, Y., Xu, C., Kuno, Y., Simpson, C., Wark, D., Di Lodovico, F., Richards, B., Sedgwick, S. Molina, Tacik, R., Kim, S. B., Thiesse, M., Thompson, L., Okazawa, H., Choi, Y., Nishijima, K., Koshiba, M., Yokoyama, M., Goldsack, A., Martens, K., Murdoch, M., Quilain, B., Suzuki, Y., Vagins, M. R., Kuze, M., Okajima, Y., Yoshida, T., Ishitsuka, M., Martin, J. F., Nantais, C. M., Tanaka, H. A., Towstego, T., Hartz, M., Konaka, A., de Perio, P., Chen, S., and Minamino, A.
Subjects: High Energy Physics - Experiment
Abstract: Neutral current (NC) interactions of atmospheric neutrinos on oxygen form one of the major backgrounds in the search for supernova relic neutrinos with water-based Cherenkov detectors. The NC channel is dominated by neutrino quasi-elastic (NCQE) scattering off nucleons inside $^{16}$O nuclei. In this paper we report the first measurement of NCQE cross section using atmospheric neutrinos at Super-Kamiokande (SK). The measurement used 2,778 live days of SK-IV data with a fiducial volume of 22.5 kiloton water. Within the visible energy window of 7.5-29.5 MeV, we observed $117$ events compared to the expected $71.9$ NCQE signal and $53.1$ background events. Weighted by the atmospheric neutrino spectrum from 160 MeV to 10 GeV, the flux averaged NCQE cross section is measured to be $(1.01\pm0.17(\text{stat.})^{+0.78}_{-0.30}(\text{sys.}))\times10^{-38}$ cm$^2$., Comment: 11 pages, 9 figures, submitted to PRD
Published: 2019
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41. Atmospheric Neutrino Oscillation Analysis With Improved Event Reconstruction in Super-Kamiokande IV

Author: Collaboration, Super-Kamiokande, Jiang, M., Abe, K., Bronner, C., Hayato, Y., Ikeda, M., Iyogi, K., Kameda, J., Kato, Y., Kishimoto, Y., Marti, Ll., Miura, M., Moriyama, S., Mochizuki, T., Nakahata, M., Nakajima, Y., Nakano, Y., Nakayama, S., Okada, T., Okamoto, K., Orii, A., Pronost, G., Sekiya, H., Shiozawa, M., Sonoda, Y., Takeda, A., Takenaka, A., Tanaka, H., Yano, T., Akutsu, R., Kajita, T., Nishimura, Y., Okumura, K., Wang, R., Xia, J., Labarga, L., Fernandez, P., Blaszczyk, F. d. M., Kachulis, C., Kearns, E., Raaf, J. L., Stone, J. L., Sussman, S., Berkman, S., Bian, J., Griskevich, N. J., Kropp, W. R., Locke, S., Mine, S., Weatherly, P., Smy, M. B., Sobel, H. W., Takhistov, V., Ganezer, K. S., Hill, J., Kim, J. Y., Lim, I. T., Park, R. G., Bodur, B., Scholberg, K., Walter, C. W., Drapier, O., Gonin, M., Imber, J., Mueller, Th. A., Paganini, P., Ishizuka, T., Nakamura, T., Jang, J. S., Choi, K., Learned, J. G., Matsuno, S., Litchfield, R. P., Sztuc, A. A., Uchida, Y., Wascko, M. O., Calabria, N. F., Catanesi, M. G., Intonti, R. A., Radicioni, E., De Rosa, G., Ali, A., Collazuol, G., Iacob, F., Ludovici, L., Cao, S., Friend, M., Hasegawa, T., Ishida, T., Kobayashi, T., Nakadaira, T., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Abe, KE., Hasegawa, M., Isobe, Y., Miyabe, H., Sugimoto, T., Suzuki, A. T., Takeuchi, Y., Ashida, Y., Hayashino, T., Hirota, S., Kikawa, T., Mori, M., Nakamura, KE., Nakaya, T., Wendell, R. A., Anthony, L. H. V., McCauley, N., Pritchard, A., Tsui, K. M., Fukuda, Y., Itow, Y., Murrase, M., Mijakowski, P., Frankiewicz, K., Jung, C. K., Li, X., Palomino, J. L., Santucci, G., Vilela, C., Wilking, M. J., Yanagisawa, C., Fukuda, D., Hagiwara, K., Ishino, H., Ito, S., Koshio, Y., Sakuda, M., Takahira, Y., Xu, C., Kuno, Y., Simpson, C., Wark, D., Di Lodovico, F., Richards, B., Sedgwick, S. Molina, Tacik, R., Kim, S. B., Thiesse, M., Thompson, L., Okazawa, H., Choi, Y., Nishijima, K., Koshiba, M., Yokoyama, M., Goldsack, A., Martens, K., Murdoch, M., Quilain, B., Suzuki, Y., Vagins, M. R., Kuze, M., Okajima, Y., Yoshida, T., Ishitsuka, M., Martin, J. F., Nantais, C. M., Tanaka, H. A., Towstego, T., Hartz, M., Konaka, A., de Perio, P., Chen, S., Wan, L., and Minamino, A.
Subjects: High Energy Physics - Experiment
Abstract: A new event reconstruction algorithm based on a maximum likelihood method has been developed for Super-Kamiokande. Its improved kinematic and particle identification capabilities enable the analysis of atmospheric neutrino data in a detector volume 32% larger than previous analyses and increases sensitivity to the neutrino mass hierarchy. Analysis of a 253.9 kton-year exposure of the Super-Kamiokande IV atmospheric neutrino data has yielded a weak preference for the normal hierarchy, disfavoring the inverted hierarchy at 74% assuming oscillations at the best fit of the analysis., Comment: 42 pages, 28 figures, submitted to PTEP
Published: 2019
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42. Dinucleon and Nucleon Decay to Two-Body Final States with no Hadrons in Super-Kamiokande

Author: Collaboration, Super-Kamiokande, Sussman, S., Abe, K., Bronner, C., Hayato, Y., Ikeda, M., Iyogi, K., Kameda, J., Kato, Y., Kishimoto, Y., Marti, Ll., Miura, M., Moriyama, S., Mochizuki, T., Nakahata, M., Nakajima, Y., Nakano, Y., Nakayama, S., Okada, T., Okamoto, K., Orii, A., Pronost, G., Sekiya, H., Shiozawa, M., Sonoda, Y., Takeda, A., Takenaka, A., Tanaka, H., Yano, T., Akutsu, R., Kajita, T., Nishimura, Y., Okumura, K., Wang, R., Xia, J., Labarga, L., Fernandez, P., Blaszczyk, F. d. M., Kachulis, C., Kearns, E., Raaf, J. L., Stone, J. L., Berkman, S., Bian, J., Griskevich, N. J., Kropp, W. R., Locke, S., Mine, S., Weatherly, P., Smy, M. B., Sobel, H. W., Takhistov, V., Ganezer, K. S., Hill, J., Kim, J. Y., Lim, I. T., Park, R. G., Bodur, B., Scholberg, K., Walter, C. W., Drapier, O., Gonin, M., Imber, J., Mueller, Th. A., Paganini, P., Ishizuka, T., Nakamura, T., Jang, J. S., Choi, K., Learned, J. G., Matsuno, S., Litchfield, R. P., Sztuc, A. A., Uchida, Y., Wascko, M. O., Calabria, N. F., Catanesi, M. G., Intonti, R. A., Radicioni, E., De Rosa, G., Ali, A., Collazuol, G., Iacob, F., Ludovici, L., Cao, S., Friend, M., Hasegawa, T., Ishida, T., Kobayashi, T., Nakadaira, T., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Abe, KE., Hasegawa, M., Isobe, Y., Miyabe, H., Sugimoto, T., Suzuki, A. T., Takeuchi, Y., Ashida, Y., Hayashino, T., Hirota, S., Jiang, M., Kikawa, T., Mori, M., Nakamura, KE., Nakaya, T., Wendell, R. A., Anthony, L. H. V., McCauley, N., Pritchard, A., Tsui, K. M., Fukuda, Y., Itow, Y., Murrase, M., Mijakowski, P., Frankiewicz, K., Jung, C. K., Li, X., Palomino, J. L., Santucci, G., Vilela, C., Wilking, M. J., Yanagisawa, C., Fukuda, D., Hagiwara, K., Ishino, H., Ito, S., Koshio, Y., Sakuda, M., Takahira, Y., Xu, C., Kuno, Y., Simpson, C., Wark, D., Di Lodovico, F., Richards, B., Sedgwick, S. Molina, Tacik, R., Kim, S. B., Thiesse, M., Thompson, L., Okazawa, H., Choi, Y., Nishijima, K., Koshiba, M., Yokoyama, M., Goldsack, A., Martens, K., Murdoch, M., Quilain, B., Suzuki, Y., Vagins, M. R., Kuze, M., Okajima, Y., Yoshida, T., Ishitsuka, M., Martin, J. F., Nantais, C. M., Tanaka, H. A., Towstego, T., Hartz, M., Konaka, A., de Perio, P., Chen, S., Wan, L., and Minamino, A.
Subjects: High Energy Physics - Experiment
Abstract: Using 0.37 megaton$\cdot$years of exposure from the Super-Kamiokande detector, we search for 10 dinucleon and nucleon decay modes that have a two-body final state with no hadrons. These baryon and lepton number violating modes have the potential to probe theories of unification and baryogenesis. For five of these modes the searches are novel, and for the other five modes we improve the limits by more than one order of magnitude. No significant evidence for dinucleon or nucleon decay is observed and we set lower limits on the partial lifetime of oxygen nuclei and on the nucleon partial lifetime that are above $4\times 10^{33}$ years for oxygen via the dinucleon decay modes and up to about $4 \times 10^{34}$ years for nucleons via the single nucleon decay modes.
Published: 2018

43. Search for Neutrinos in Super-Kamiokande associated with the GW170817 neutron-star merger

Author: Abe, K., Bronner, C., Hayato, Y., Ikeda, M., Iyogi, K., Kameda, J., Kato, Y., Kishimoto, Y., Marti, Ll., Miura, M., Moriyama, S., Nakahata, M., Nakajima, Y., Nakano, Y., Nakayama, S., Orii, A., Pronost, G., Sekiya, H., Shiozawa, M., Sonoda, Y., Takeda, A., Takenaka, A., Tanaka, H., Tasaka, S., Yano, T., Akutsu, R., Kajita, T., Nishimura, Y., Okumura, K., Tsui, K. M., Labarga, L., Fernandez, P., Blaszczyk, F. d. M., Kachulis, C., Kearns, E., Raaf, J. L., Stone, J. L., Sulak, L. R., Berkman, S., Tobayama, S., Bian, J., Elnimr, M., Kropp, W. R., Locke, S., Mine, S., Weatherly, P., Smy, M. B., Sobel, H. W., Takhistov, V., Ganezer, K. S., Hill, J., Kim, J. Y., Lim, I. T., Park, R. G., Li, Z., O'Sullivan, E., Scholberg, K., Walter, C. W., Gonin, M., Imber, J., Mueller, Th. A., Ishizuka, T., Nakamura, T., Jang, J. S., Choi, K., Learned, J. G., Matsuno, S., Amey, J., Litchfield, R. P., Ma, W. Y., Uchida, Y., Wascko, M. O., Catanesi, M. G., Intonti, R. A., Radicioni, E., De Rosa, G., Ali, A., Collazuol, G., Ludovici, L., Cao, S., Friend, M., Hasegawa, T., Ishida, T., Ishii, T., Kobayashi, T., Nakadaira, T., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Abe, KE., Hasegawa, M., Suzuki, A. T., Takeuchi, Y., Hayashino, T., Hirota, S., Jiang, M., Mori, M., Nakamura, KE., Nakaya, T., Wendell, R. A., Anthony, L. H. V., McCauley, N., Pritchard, A., Fukuda, Y., Itow, Y., Murase, M., Muto, F., Mijakowski, P., Frankiewicz, K., Jung, C. K., Li, X., Palomino, J. L., Santucci, G., Viela, C., Wilking, M. J., Yanagisawa, C., Fukuda, D., Ishino, H., Ito, S., Kibayashi, A., Koshio, Y., Nagata, H., Sakuda, M., Xu, C., Kuno, Y., Wark, D., Di Lodovico, F., Richards, B., Sedgwick, S. Molina, Tacik, R., Kim, S. B., Cole, A., Thompson, L., Okazawa, H., Choi, Y., Ito, K., Nishijima, K., Koshiba, M., Suda, Y., Yokoyama, M., Calland, R. G., Hartz, M., Martens, K., Murdoch, M., Quilain, B., Simpson, C., Suzuki, Y., Vagins, M. R., Hamabe, D., Kuze, M., Okajima, Y., Yoshida, T., Ishitsuka, M., Martin, J. F., Nantais, C. M., Tanaka, H. A., Towstego, T., Konaka, A., Chen, S., Wan, L., and Minamino, A.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: We report the results of a neutrino search in Super-Kamiokande for coincident signals with the first detected gravitational wave produced by a binary neutron star merger, GW170817, which was followed by a short gamma-ray burst, GRB170817A, and a kilonova/macronova. We searched for coincident neutrino events in the range from 3.5 MeV to $\sim$100 PeV, in a time window $\pm$500 seconds around the gravitational wave detection time, as well as during a 14-day period after the detection. No significant neutrino signal was observed for either time window. We calculated 90% confidence level upper limits on the neutrino fluence for GW170817. From the upward-going-muon events in the energy region above 1.6 GeV, the neutrino fluence limit is $16.0^{+0.7}_{-0.6}$ ($21.3^{+1.1}_{-0.8}$) cm$^{-2}$ for muon neutrinos (muon antineutrinos), with an error range of $\pm5^{\circ}$ around the zenith angle of NGC4993, and the energy spectrum is under the assumption of an index of $-2$. The fluence limit for neutrino energies less than 100 MeV, for which the emission mechanism would be different than for higher-energy neutrinos, is also calculated. It is $6.6 \times 10^7$ cm$^{-2}$ for anti-electron neutrinos under the assumption of a Fermi-Dirac spectrum with average energy of 20 MeV., Comment: 8 pages, 4 figures
Published: 2018
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44. A Measurement of the Tau Neutrino Cross Section in Atmospheric Neutrino Oscillations with Super-Kamiokande

Author: Collaboration, Super-Kamiokande, Li, Z., Abe, K., Bronner, C., Hayato, Y., Ikeda, M., Iyogi, K., Kameda, J., Kato, Y., Kishimoto, Y., Marti, Ll., Miura, M., Moriyama, S., Nakahata, M., Nakajima, Y., Nakano, Y., Nakayama, S., Orii, A., Pronost, G., Sekiya, H., Shiozawa, M., Sonoda, Y., Takeda, A., Takenaka, A., Tanaka, H., Tasaka, S., Tomura, T., Akutsu, R., Kajita, T., Nishimura, Y., Okumura, K., Tsui, K. M., Fernandez, P., Labarga, L., Blaszczyk, F. d. M., Gustafson, J., Kachulis, C., Kearns, E., Raaf, J. L., Stone, J. L., Sulak, L. R., Berkman, S., Tobayama, S., Elnimr, M., Kropp, W. R., Locke, S., Mine, S., Weatherly, P., Smy, M. B., Sobel, H. W., Takhistov, V., Ganezer, K. S., Hill, J., Kim, J. Y., Lim, I. T., Park, R. G., Himmel, A., O'Sullivan, E., Scholberg, K., Walter, C. W., Ishizuka, T., Nakamura, T., Jang, J. S., Choi, K., Learned, J. G., Matsuno, S., Smith, S. N., Amey, J., Litchfield, R. P., Ma, W. Y., Uchida, Y., Wascko, M. O., Cao, S., Friend, M., Hasegawa, T., Ishida, T., Ishii, T., Kobayashi, T., Nakadaira, T., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Abe, KE., Hasegawa, M., Suzuki, A. T., Takeuchi, Y., Yano, T., Hayashino, T., Hiraki, T., Hirota, S., Huang, K., Jiang, M., Mori, M., Nakamura, KE., Nakaya, T., Patel, N. D., Wendell, R. A., Anthony, L. H. V., McCauley, N., Pritchard, A., Fukuda, Y., Itow, Y., Murase, M., Muto, F., Mijakowski, P., Frankiewicz, K., Jung, C. K., Li, X., Palomino, J. L., Santucci, G., Vilela, C., Wilking, M. J., Yanagisawa, C., Yang, G., Ito, S., Fukuda, D., Ishino, H., Kibayashi, A., Koshio, Y., Nagata, H., Sakuda, M., Xu, C., Kuno, Y., Wark, D., Di Lodovico, F., Richards, B., Sedgwick, S. M., Tacik, R., Kim, S. B., Cole, A., Thompson, L., Okazawa, H., Choi, Y., Ito, K., Nishijima, K., Koshiba, M., Suda, Y., Yokoyama, M., Calland, R. G., Hartz, M., Martens, K., Murdoch, M., Quilain, B., Simpson, C., Suzuki, Y., Vagins, M. R., Hamabe, D., Kuze, M., Okajima, Y., Yoshida, T., Ishitsuka, M., Martin, J. F., Nantais, C. M., Tanaka, H. A., Towstego, T., Konaka, A., Chen, S., Wan, L., Zhang, Y., Minamino, A., and Wilkes, R. J.
Subjects: High Energy Physics - Experiment
Abstract: Using 5,326 days of atmospheric neutrino data, a search for atmospheric tau neutrino appearance has been performed in the Super-Kamiokande experiment. Super-Kamiokande measures the tau normalization to be 1.47$\pm$0.32 under the assumption of normal neutrino hierarchy, relative to the expectation of unity with neutrino oscillation. The result excludes the hypothesis of no-tau-appearance with a significance level of 4.6$\sigma$. The inclusive charged-current tau neutrino cross section averaged by the tau neutrino flux at Super-Kamiokande is measured to be $(0.94\pm0.20)\times 10^{-38}$ cm$^{2}$. The measurement is consistent with the Standard Model prediction, agreeing to within 1.5$\sigma$.
Published: 2017
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45. Search for Boosted Dark Matter Interacting With Electrons in Super-Kamiokande

Author: Collaboration, Super-Kamiokande, Kachulis, C., Abe, K., Bronner, C., Hayato, Y., Ikeda, M., Iyogi, K., Kameda, J., Kato, Y., Kishimoto, Y., Marti, Ll., Miura, M., Moriyama, S., Nakahata, M., Nakano, Y., Nakayama, S., Okajima, Y., Orii, A., Pronost, G., Sekiya, H., Shiozawa, M., Sonoda, Y., Takeda, A., Takenaka, A., Tanaka, H., Tasaka, S., Tomura, T., Akutsu, R., Kajita, T., Kaneyuki, K., Nishimura, Y., Okumura, K., Tsui, K. M., Labarga, L., Fernandez, P., Blaszczyk., F. d. M., Gustafson, J., Kearns, E., Raaf, J. L., Stone, J. L., Sulak, L. R., Berkman, S., Tobayama, S., Goldhaber, M., Elnimr, M., Kropp, W. R., Mine, S., Locke, S., Weatherly, P., Smy, M. B., Sobel, H. W., Takhistov, V., Ganezer, K. S., Hill, J., Kim, J. Y., Lim, I. T., Park, R. G., Himmel, A., Li, Z., O'Sullivan, E., Scholberg, K., Walter, C. W., Ishizuka, T., Nakamura, T., Jang, J. S., Choi, K., Learned, J. G., Matsuno, S., Smith, S. N., Amey, J., Litchfield, R. P., Ma, W. Y., Wascko, Y. Uchida. M. O., Cao, S., Friend, M., Hasegawa, T., Ishida, T., Ishii, T., Kobayashi, T., Nakadaira, T., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Abe, KE., Hasegawa, M., Suzuki, A. T., Takeuchi, Y., Yano, T., Hayashino, T., Hiraki, T., Hirota, S., Huang, K., Jiang, M., Nakamura, KE., Nakaya, T., Quilain, B., Patel, N. D., Wendell, R. A., Anthony, L. H. V., McCauley, N., Pritchard, A., Fukuda, Y., Itow, Y., Murase, M., Muto, F., Mijakowski, P., Frankiewicz, K., Jung, C. K., Li, X., Palomino, J. L., Santucci, G., Vilela, C., Wilking, M. J., Yanagisawa, C., Ito, S., Fukuda, D., Ishino, H., Kibayashi, A., Koshio, Y., Nagata, H., Sakuda, M., Xu, C., Kuno, Y., Wark, D., Di Lodovico, F., Richards, B., Tacik, R., Kim, S. B., Cole, A., Thompson, L., Okazawa, H., Choi, Y., Ito, K., Nishijima, K., Koshiba, M., Totsuka, Y., Suda, Y., Yokoyama, M., Calland, R. G., Hartz, M., Martens, K., Simpson, C., Suzuki, Y., Vagins, M. R., Hamabe, D., Kuze, M., Yoshida, T., Ishitsuka, M., Martin, J. F., Nantais, C. M., Tanaka, H. A., Konaka, A., Chen, S., Wan, L., Zhang, Y., Wilkes, R. J., and Minamino, A.
Subjects: High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: A search for boosted dark matter using 161.9 kiloton-years of Super-Kamiokande IV data is presented. We search for an excess of elastically scattered electrons above the atmospheric neutrino background, with a visible energy between 100 MeV and 1 TeV, pointing back to the Galactic Center or the Sun. No such excess is observed. Limits on boosted dark matter event rates in multiple angular cones around the Galactic Center and Sun are calculated. Limits are also calculated for a baseline model of boosted dark matter produced from cold dark matter annihilation or decay.
Published: 2017
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46. Atmospheric neutrino oscillation analysis with external constraints in Super-Kamiokande I-IV

Author: Collaboration, Super-Kamiokande, Abe, K., Bronner, C., Haga, Y., Hayato, Y., Ikeda, M., Iyogi, K., Kameda, J., Kato, Y., Kishimoto, Y., Marti, Ll., Miura, M., Moriyama, S., Nakahata, M., Nakajima, T., Nakano, Y., Nakayama, S., Okajima, Y., Orii, A., Pronost, G., Sekiya, H., Shiozawa, M., Sonoda, Y., Takeda, A., Takenaka, A., Tanaka, H., Tasaka, S., Tomura, T., Akutsu, R., Irvine, T., Kajita, T., Kametani, I., Kaneyuki, K., Nishimura, Y., Okumura, K., Richard, E., Tsui, K. M., Labarga, L., Fernandez, P., Blaszczyk, F. d. M., Gustafson, J., Kachulis, C., Kearns, E., Raaf, J. L., Stone, J. L., Sulak, L. R., Berkman, S., Tobayama, S., Goldhaber, M., Carminati, G., Elnimr, M., Kropp, W. R., Mine, S., Locke, S., Renshaw, A., Smy, M. B., Sobel, H. W., Takhistov, V., Weatherly, P., Ganezer, K. S., Hartfiel, B. L., Hill, J., Hong, N., Kim, J. Y., Lim, I. T., Park, R. G., Akiri, T., Himmel, A., Li, Z., O'Sullivan, E., Scholberg, K., Walter, C. W., Wongjirad, T., Ishizuka, T., Nakamura, T., Jang, J. S., Choi, K., Learned, J. G., Matsuno, S., Smith, S. N., Amey, J., Litchfield, R. P., Ma, W. Y., Uchida, Y., Wascko, M. O., Cao, S., Friend, M., Hasegawa, T., Ishida, T., Ishii, T., Kobayashi, T., Nakadaira, T., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Abe, KE., Hasegawa, M., Suzuki, A. T., Takeuchi, Y., Yano, T., Hayashino, T., Hirota, S., Huang, K., Ieki, K., Jiang, M., Kikawa, T., Nakamura, KE., Nakaya, T., Patel, N. D., Suzuki, K., Takahashi, S., Wendell, R. A., Anthony, L. H. V., McCauley, N., Pritchard, A., Fukuda, Y., Itow, Y., Mitsuka, G., Murase, M., Muto, F., Suzuki, T., Mijakowski, P., Frankiewicz, K., Hignight, J., Imber, J., Jung, C. K., Li, X., Palomino, J. L., Santucci, G., Vilela, C., Wilking, M. J., Yanagisawa, C., Ito, S., Fukuda, D., Ishino, H., Kayano, T., Kibayashi, A., Koshio, Y., Mori, T., Nagata, H., Sakuda, M., Xu, C., Kuno, Y., Wark, D., Di Lodovico, F., Richards, B., Tacik, R., Kim, S. B., Cole, A., Thompson, L., Okazawa, H., Choi, Y., Ito, K., Nishijima, K., Koshiba, M., Totsuka, Y., Suda, Y., Yokoyama, M., Calland, R. G., Hartz, M., Martens, K., Quilain, B., Simpson, C., Suzuki, Y., Vagins, M. R., Hamabe, D., Kuze, M., Yoshida, T., Ishitsuka, M., Martin, J. F., Nantais, C. M., de Perio, P., Tanaka, H. A., Konaka, A., Chen, S., Wan, L., Zhang, Y., Wilkes, R. J., and Minamino, A.
Subjects: High Energy Physics - Experiment
Abstract: An analysis of atmospheric neutrino data from all four run periods of \superk optimized for sensitivity to the neutrino mass hierarchy is presented. Confidence intervals for $\Delta m^2_{32}$, $\sin^2 \theta_{23}$, $\sin^2 \theta_{13}$ and $\delta_{CP}$ are presented for normal neutrino mass hierarchy and inverted neutrino mass hierarchy hypotheses based on atmospheric neutrino data alone. Additional constraints from reactor data on $\theta_{13}$ and from published binned T2K data on muon neutrino disappearance and electron neutrino appearance are added to the atmospheric neutrino fit to give enhanced constraints on the above parameters. Over the range of parameters allowed at 90% confidence level, the normal mass hierarchy is favored by between 91.5% and 94.5% based on the combined result., Comment: 22 pages, 29 figures, final version submitted for publication
Published: 2017
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47. Search for an excess of events in the Super-Kamiokande detector in the directions of the astrophysical neutrinos reported by the IceCube Collaboration

Author: Collaboration, The Super-Kamiokande, Abe, K., Bronner, C., Pronost, G., Hayato, Y., Ikeda, M., Iyogi, K., Kameda, J., Kato, Y., Kishimoto, Y., Marti, Ll., Miura, M., Moriyama, S., Nakahata, M., Nakano, Y., Nakayama, S., Okajima, Y., Orii, A., Sekiya, H., Shiozawa, M., Sonoda, Y., Takeda, A., Takenaka, A., Tanaka, H., Tasaka, S., Tomura, T., Akutsu, R., Kajita, T., Kaneyuki, K., Nishimura, Y., Okumura, K., Tsui, K. M., Labarga, L., Fernandez, P., Blaszczyk, F. d. M., Gustafson, J., Kachulis, C., Kearns, E., Raaf, J. L., Stone, J. L., Sulak, L. R., Berkman, S., Tobayama, S., Goldhaber, M., Elnimr, M., Kropp, W. R., Mine, S., Locke, S., Weatherly, P., Smy, M. B., Sobel, H. W., Takhistov, V., Ganezer, K. S., Hill, J., Kim, J. Y., Lim, I. T., Park, R. G., Himmel, A., Li, Z., O'Sullivan, E., Scholberg, K., Walter, C. W., Ishizuka, T., Nakamura, T., Jang, J. S., Choi, K., Learned, J. G., Matsuno, S., Smith, S. N., Amey, J., Litchfield, R. P., Ma, W. Y., Uchida, Y., Wascko, M. O., Cao, S., Friend, M., Hasegawa, T., Ishida, T., Ishii, T., Kobayashi, T., Nakadaira, T., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Abe, KE., Hasegawa, M., Suzuki, A. T., Takeuchi, Y., Yano, T., Cao, S. V., Hayashino, T., Hiraki, T., Hirota, S., Huang, K., Jiang, M., Minamino, A., Nakamura, KE., Nakaya, T., Quilain, B., Patel, N. D., Wendell, R. A., Anthony, L. H. V., McCauley, N., Pritchard, A., Fukuda, Y., Itow, Y., Murase, M., Muto, F., Mijakowski, P., Frankiewicz, K., Jung, C. K., Li, X., Palomino, J. L., Santucci, G., Vilela, C., Wilking, M. J., Yanagisawa, C., Ito, S., Fukuda, D., Ishino, H., Kibayashi, A., Koshio, Y., Nagata, H., Sakuda, M., Xu, C., Kuno, Y., Wark, D., Di Lodovico, F., Richards, B., Tacik, R., Kim, S. B., Cole, A., Thompson, L., Okazawa, H., Choi, Y., Ito, K., Nishijima, K., Koshiba, M., Totsuka, Y., Suda, Y., Yokoyama, M., Calland, R. G., Hartz, M., Martens, K., Simpson, C., Suzuki, Y., Vagins, M. R., Hamabe, D., Kuze, M., Yoshida, T., Ishitsuka, M., Martin, J. F., Nantais, C. M., Tanaka, H. A., Konaka, A., Chen, S., Wan, L., Zhang, Y., and Wilkes, R. J.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, High Energy Physics - Experiment
Abstract: We present the results of a search in the Super-Kamiokande (SK) detector for excesses of neutrinos with energies above a few GeV that are in the direction of the track events reported in IceCube. Data from all SK phases (SK-I through SK-IV) were used, spanning a period from April 1996 to April 2016 and corresponding to an exposure of 225 kilotonne-years . We considered the 14 IceCube track events from a data set with 1347 livetime days taken from 2010 to 2014. We use Poisson counting to determine if there is an excess of neutrinos detected in SK in a 10 degree search cone (5 degrees for the highest energy data set) around the reconstructed direction of the IceCube event. No significant excess was found in any of the search directions we examined. We also looked for coincidences with a recently reported IceCube multiplet event. No events were detected within a $\pm$ 500 s time window around the first detected event, and no significant excess was seen from that direction over the lifetime of SK., Comment: 9 pages, 4 figures, Matches version published in Astrophysical Journal
Published: 2017
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48. Spectral Measurement of the Electron Antineutrino Oscillation Amplitude and Frequency using 500 Live Days of RENO Data

Author: Seo, S. H., Choi, W. Q., Seo, H., Choi, J. H., Choi, Y., Jang, H. I., Jang, J. S., Joo, K. K., Kim, B. R., Kim, H. S., Kim, J. Y., Kim, S. B., Kim, S. Y., Kim, W., Kwon, E., Lee, D. H., Lee, Y. C., Lim, I. T., Pac, M. Y., Park, I. G., Park, J. S., Park, R. G., Seon, Y. G., Shin, C. D., Yang, J. H., Yang, J. Y., Yeo, I. S., and Yu, I.
Subjects: High Energy Physics - Experiment, Physics - Instrumentation and Detectors
Abstract: The Reactor Experiment for Neutrino Oscillation (RENO) has been taking electron antineutrino ($\overline{\nu}_{e}$) data from the reactors in Yonggwang, Korea, using two identical detectors since August 2011. Using roughly 500 live days of data through January 2013 we observe 290,775 (31,514) reactor $\overline{\nu}_{e}$ candidate events with 2.8 (4.9)% background in the near (far) detector. The observed visible positron spectra from the reactor $\overline{\nu}_{e}$ events in both detectors show discrepancy around 5 MeV with regard to the prediction from the current reactor $\overline{\nu}_{e}$ model. Based on a far-to-near ratio measurement using the spectral and rate information we have obtained $\sin^2 2 \theta_{13} = 0.082 \pm 0.009({\rm stat.}) \pm 0.006({\rm syst.})$ and $|\Delta m_{ee}^2| =[2.62_{-0.23}^{+0.21}({\rm stat.})_{-0.13}^{+0.12}({\rm syst.})]\times 10^{-3}$eV$^2$., Comment: 24 pages, 30 figures. Submitted to PRD. Total detection efficiency change from 76.44% to 76.47%. Some modifications of text to improve readability and clarification of the paper
Published: 2016
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49. In-Situ Measurement of Relative Attenuation Length of Gadolinium-Loaded Liquid Scintillator Using Source Data at RENO Experiment

Author: Kim, H. S., Kim, S. Y., Choi, J. H., Choi, W. Q., Choi, Y., Jang, H. I., Jang, J. S., Joo, K. K., Kim, B. R., Kim, J. Y., Kim, S. B., Kim, W., Kwon, E., Lee, D. H., Lim, I. T., Pac, M. Y., Park, I. G., Park, J. S., Park, R. G., Seo, H., Seo, S. H., Seon, Y. G., Shin, C. D., Yeo, I. S., and Yu, I.
Subjects: Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract: We present in situ measurements of the relative attenuation length of the gadolinium loaded liquid scintillator in the RENO (Reactor Experiment Neutrino Oscillation) detectors using radioactive source calibration data. We observed a steady decrease in the attenuation length of the Gd-LS in the RENO detectors by 50% in about four years since the commissioning of the detectors., Comment: 11 pages, 5 figures
Published: 2016
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50. Search for Neutrinos in Super-Kamiokande associated with Gravitational Wave Events GW150914 and GW151226

Author: Abe, K., Haga, K., Hayato, Y., Ikeda, M., Iyogi, K., Kameda, J., Kishimoto, Y., Miura, M., Moriyama, S., Nakahata, M., Nakajima, T., Nakano, Y., Nakayama, S., Orii, A., Sekiya, H., Shiozawa, M., Takeda, A., Tanaka, H., Tasaka, S., Tomura, T., Akutsu, R., Kajita, T., Kaneyuki, K., Nishimura, Y., Richard, E., Okumura, K., Labarga, L., Fernandez, P., Blaszczyk, F. d. M., Gustafson, J., Kachulis, C., Kearns, E., Raaf, J. L., Stone, J. L., Sulak, L. R., Berkman, S., Nantais, C. M., Tobayama, S., Goldhaber, M., Kropp, W. R., Mine, S., Weatherly, P., Smy, M. B., Sobel, H. W., Takhistov, V., Ganezer, K. S., Hartfiel, B. L., Hil, J., Hong, N., Kim, J. Y., Lim, I. T., Park, R. G., Himmel, A., Li, Z., O'Sullivan, E., Scholberg, K., Walter, C. W., Ishizuka, T., Nakamura, T., Jang, J. S., Choi, K., Learned, J. G., Matsuno, S., Smith, S. N., Friend, M., Hasegawa, T., Ishida, T., Ishii, T., Kobayashi, T., Nakadaira, T., Nakamura, K., Oyama, Y., Sakashita, K., Sekiguchi, T., Tsukamoto, T., Suzuki, A. T., Takeuchi, Y., Yano, T., Cao, S. V., Hiraki, T., Hirota, S., Huang, K., Jiang, M., Minamino, A., Nakaya, T., Patel, N. D., Wendell, R. A., Suzuki, K., Fukuda, Y., Itow, Y., Suzuki, T., Mijakowski, P., Frankiewicz, K., Hignight, J., Imber, J., Jung, C. K., Li, X., Palomino, J. L., Santucci, G., Wilking, M. J., Yanagisawa, C., Fukuda, D., Ishino, H., Kayano, T., Kibayashi, A., Koshio, Y., Mori, T., Sakuda, M., Xu, C., Kuno, Y., Tacik, R., Kim, S. B., Okazawa, H., Choi, Y., Nishijima, K., Koshiba, M., Totsuka, Y., Suda, Y., Yokoyama, M., Bronner, C., Calland, R. G., Hartz, M., Martens, K., Marti, Ll., Suzuki, Y., Vagins, M. R., Martin, J. F., Tanaka, H. A., Konaka, A., Chen, S., Wan, L., Zhang, Y., and Wilkes, R. J.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, High Energy Physics - Experiment
Abstract: We report the results from a search in Super-Kamiokande for neutrino signals coincident with the first detected gravitational wave events, GW150914 and GW151226, using a neutrino energy range from 3.5 MeV to 100 PeV. We searched for coincident neutrino events within a time window of $\pm$500 seconds around the gravitational wave detection time. Four neutrino candidates are found for GW150914 and no candidates are found for GW151226. The remaining neutrino candidates are consistent with the expected background events. We calculated the 90\% confidence level upper limits on the combined neutrino fluence for both gravitational wave events, which depends on event energy and topologies. Considering the upward going muon data set (1.6 GeV - 100 PeV) the neutrino fluence limit for each gravitational wave event is 14 - 37 (19 - 50) cm$^{-2}$ for muon neutrinos (muon antineutrinos), depending on the zenith angle of the event. In the other data sets, the combined fluence limits for both gravitational wave events range from 2.4$\times 10^{4}$ to 7.0$\times 10^{9}$ cm$^{-2}$., Comment: 8 pages, 4 figures
Published: 2016
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