Search for proton decay via p → e + π 0 and p → μ + π 0 with an enlarged fiducial volume in Super-Kamiokande I-IV

作者：A. Takenaka, Kazuki ABE, C. Bronner, Y. Hayato, M. Ikeda, S. Imaizumi, Hiroshi Itô, J. Kameda, Y. Kataoka, Y. Kato, Y. Kishimoto, Ll. Marti, M. Miura, S. Moriyama, Takeshi MOCHIZUKI, Y. Nagao, Masayuki Nakahata, Y. Nakajima, S. Nakayama, T. Okada, Ken‐ichi Okamoto, A. Orii, G. Pronost, H. Sekiya, M. Shiozawa, Y. Sonoda, Y. Suzuki, A. Takeda, Y. Takemoto, Hiroyuki K. M. TANAKA, T. Yano, R. Akutsu, S. Han, T. Kajita, K. Okumura, T. Tashiro, R. Wang, J. Xia, David Bravo, L. Labarga, Pablo Fernández, B. Zaldivar, F. d. M. Blaszczyk, E. Kearns, J. L. Raaf, J. L. Stone, L. Wan, Thomas E. Wester, B. W. Pointon, J. Bian, N. Jeff Griskevich, W. R. Kropp, Scott Locke, S. Mine, M. B. SMY, H. W. Sobel, Volodymyr Takhistov, P. Weatherly, K. S. Ganezer, J. Hill, J. Y. Kim, I. T. Lim, R. G. Park, B. Bodur, K. Scholberg, C. W. Walter, A. Coffani, O. Drapier, S. El Hedri, A. Giampaolo, M. Gonin, Th. A. Mueller, P. Paganini, B. Quilain, T. Ishizuka, T. Nakamura, J. S. Jang, J. G. Learned, S. Matsuno, L. H. V. Anthony, R. P. Litchfield, Artur A. Sztuc, Y. Uchida, V. Berardi, M. G. Catanesi, E. Radicioni, Nicola Fulvio Calabria, Lucas Nascimento Machado, G. De Rosa, G. Collazuol, F. Iacob, M. Lamoureux, N. Ospina, L. Ludovici, Y. Nishimura, S. Cao, M. Friend, T. Hasegawa, T. Ishida, M. Jakkapu, T. Kobayashi, T. Matsubara, T. Nakadaira, K. Nakamura, Y. Oyama, K. Sakashita, T. Sekiguchi, Toshifumi Tsukamoto, M. Hasegawa, Yuki Isobe, H. Miyabe, Y. Nakano, Tatsushi SHIOZAWA, T. Sugimoto, Atsumu Suzuki, Y. Takeuchi, S. Yamamoto, A. Ali, Yosuke Ashida, Jie Feng, S. Hirota, A. K. Ichikawa, M. Jiang, T. Kikawa, M. Mori, KE. Nakamura, T. Nakaya, R. A. Wendell, K. Yasutome, N. McCauley, P. Mehta, A. Pritchard, K. M. Tsui, Y. Fukuda, Y. Itow, H. Menjo, T. Niwa, K. Satô, M. Taani, M Tsukada, P. Mijakowski, K. Frankiewicz, Chang Kee Jung, G. Santucci, C. Vilela, M. J. Wilking, C. Yanagisawa, D. Fukuda, M. Harada, K. Hagiwara, T. Horai, H. Ishino, S. Ito, Y. Koshio, Wei Ma, Nishtha Piplani, S. Sakai, M. Sakuda, Y. Takahira, C. F. Xu, Yoshitaka Kuno, Giles Barr, D. Barrow, Lindsey Cook, Charles H. Simpson, D. Wark, F. Nova, T. Boschi, Francesca Di Lodovico, S. Molina Sedgwick, S. Zsoldos, J. Y. Yang, S. J. Jenkins, J. M. McElwee, Matthew D. Thiesse, L. F. Thompson, H. Okazawa, Y. Choi, S. B. Kim, I. Yu, K. Nishijima, M. Koshiba, K. Iwamoto, N. Ogawa, M. Yokoyama, A. Goldsack, K. Martens, Mark R. Vagins, M. Kuze, M. Tanaka, T. Yoshida, Michitaka Inomoto, M. Ishitsuka, R. Matsumoto, Kouji Ohta, M. Shinoki, J. F. Martin, C. Nantais, H. A. Tanaka, T. Towstego, M. Hartz, A. Konaka, Patrick de Perio, Nick W. Prouse, S. Chen, B. D. Xu, Magdalena Posiadała-Zezula, B. Richards, B. Jamieson, J. Walker, A. Minamino, Ken‐ichi Okamoto, G. Pintaudi, Ryu Sasaki · 发表于：Physical review. D/Physical review. D. · 年份：2020 · DOI：10.1103/physrevd.102.112011 · 被引用次数：132 · 研究领域：Particle physics theoretical and experimental studies、Dark Matter and Cosmic Phenomena、Neutrino Physics Research

We have searched for proton decay via $p\ensuremath{\rightarrow}{e}^{+}{\ensuremath{\pi}}^{0}$ and $p\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\pi}}^{0}$ modes with the enlarged fiducial volume data of Super-Kamiokande from April 1996 to May 2018, which corresponds to $450\text{ }\text{ }\mathrm{kton}\ifmmode\cdot\else\textperiodcentered\fi{}\mathrm{years}$ 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 $144\text{ }\text{ }\mathrm{kton}\ifmmode\cdot\else\textperiodcentered\fi{}\mathrm{years}$ of data, including $78\text{ }\text{ }\mathrm{kton}\ifmmode\cdot\else\textperiodcentered\fi{}\mathrm{years}$ of additional fiducial volume data, has been newly analyzed. No candidates have been found for $p\ensuremath{\rightarrow}{e}^{+}{\ensuremath{\pi}}^{0}$ and one candidate remains for $p\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\pi}}^{0}$ 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: $\ensuremath{\tau}/B(p\ensuremath{\rightarrow}{e}^{+}{\ensuremath{\pi}}^{0})>2.4\ifmmode\times\else\texttimes\fi{}{10}^{34}\text{ }\text{ }\mathrm{years}$ and $\ensuremath{\tau}/B(p\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\pi}}^{0})>1.6\ifmmode\times\else\texttimes\fi{}{10}^{34}\text{ }...