Search for proton decay via <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>p</mml:mi><mml:mo stretchy="false">→</mml:mo><mml:msup><mml:mi>μ</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>K</mml:mi><mml:mn>0</mml:mn></mml:msup></mml:math> in 0.37 megaton-years exposure of Super-Kamiokande
R. Matsumoto, K. Abe, Y. Hayato, K. Hiraide, K. Ieki, M. Ikeda, J. Kameda, Y. Kanemura, R. Kaneshima, Y. Kashiwagi, Y. Kataoka, S. Miki, S. Mine, M. Miura, S. Moriyama, Y. Nakano, M. Nakahata, S. Nakayama, Y. Noguchi, Ken‐ichi Okamoto, K. Satô, H. Sekiya, Hayato Shiba, K. Shimizu, M. Shiozawa, Y. Sonoda, Y. Suzuki, A. Takeda, Y. Takemoto, A. Takenaka, H. Tanaka, S. Watanabe, T. Yano, S. Han, T. Kajita, K. Okumura, T. Tashiro, Tomoaki Tomiya, X. Wang, J. Xia, S. Yoshida, G. D. Megias, P. Fernández, L. Labarga, N. Ospina, Bryan Zaldívar, B. W. Pointon, E. Kearns, J. L. Raaf, L. Wan, T. Wester, J. Bian, N. J. Griskevich, W. R. Kropp, S. Locke, M. B. Smy, H. W. Sobel, Volodymyr Takhistov, A. Yankelevich, J. Hill, J. Y. Kim, I. T. Lim, R. G. Park, B. Bodur, K. Scholberg, C. W. Walter, L. Bernard, A. Coffani, O. Drapier, S. El Hedri, A. Giampaolo, Th. A. Mueller, A. De Souza Santos, Pascal Paganini, B. Quilain, T. Ishizuka, T. Nakamura, J. S. Jang, J. G. Learned, K. Choi, S. Cao, L. H. V. Anthony, D. Martin, M. Scott, A. A. Sztuc, Y. Uchida, V. Berardi, M. G. Catanesi, E. Radicioni, N. F. Calabria, L. N. Machado, G. De Rosa, G. Collazuol, F. Iacob, M. Lamoureux, M. Mattiazzi, L. Ludovici, M. Gonin, G. Pronost, C. Fujisawa
Abstract
We searched for proton decay via $p\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{K}^{0}$ in $0.37\text{ }\text{ }\mathrm{Mton}\ifmmode\cdot\else\textperiodcentered\fi{}\mathrm{years}$ of data collected between 1996 and 2018 from the Super-Kamiokande water Cherenkov experiment. The selection criteria were defined separately for ${K}_{S}^{0}$ and ${K}_{L}^{0}$ channels. No significant event excess has been observed. As a result of this analysis, which extends the previous search by an additional $0.2\text{ }\text{ }\mathrm{Mton}\ifmmode\cdot\else\textperiodcentered\fi{}\mathrm{years}$ of exposure and uses an improved event reconstruction, we set a lower limit of $3.6\ifmmode\times\else\texttimes\fi{}{10}^{33}\text{ }\text{ }\mathrm{years}$ on the proton lifetime.