Search for the ¹⁶O(ppp) → ¹³C π⁺ π⁺ e⁺ Decay Mode in Super-Kamiokande Using Machine Learning Techniques

@misc{feng2026search,
  title = {{Search for the $^16\textO(ppp) \rightarrow ^13\textC π^+ π^+ e^+$ Decay Mode in Super-Kamiokande Using Machine Learning Techniques}},
  author = {J Feng and K Abe and Y Asaoka and M Harada and Y Hayato and K Hiraide and T.H Hung and K Ieki and M Ikeda and J Kameda and Y Kataoka and S Mine and M Miura and S Moriyama and K Nakagiri and M Nakahata and S Nakayama and Y Noguchi and G Pronost and K Sato and H Sekiya and R Shinoda and M Shiozawa and Y Suzuki and A Takeda and Y Takemoto and H Tanaka and S Chen and Y Itow and T Kajita and R Nishijima and K Okumura and T Tashiro and T Tomiya and X Wang and F.J de Garay Arcones and P Fernandez and L Labarga and D Samudio and C Yanagisawa and B Jargowsky and E Kearns and J Mirabito and L Wan and T Wester and B.W Pointon and J Bian and B Cortez and N.J Griskevich and Y Jiang and M.B Smy and H.W Sobel and V Takhistov and J Hill and B.D Xu and D Jung and D.H Moon and R.G Park and B.S Yang and K Scholberg},
  howpublished = {HAL},
  year = {2026},
  month = sep,
  doi = {10.48550/arxiv.2609.25681},
  eprint = {2609.25681},
  archivePrefix = {arXiv},
  url = {https://hal.science/hal-05780376v1},
}

TY  - UNPB
TI  - Search for the ^16O(ppp) → ^13C π^+ π^+ e^+ Decay Mode in Super-Kamiokande Using Machine Learning Techniques
AU  - J Feng
AU  - K Abe
AU  - Y Asaoka
AU  - M Harada
AU  - Y Hayato
AU  - K Hiraide
AU  - T.H Hung
AU  - K Ieki
AU  - M Ikeda
AU  - J Kameda
AU  - Y Kataoka
AU  - S Mine
AU  - M Miura
AU  - S Moriyama
AU  - K Nakagiri
AU  - M Nakahata
AU  - S Nakayama
AU  - Y Noguchi
AU  - G Pronost
AU  - K Sato
AU  - H Sekiya
AU  - R Shinoda
AU  - M Shiozawa
AU  - Y Suzuki
AU  - A Takeda
AU  - Y Takemoto
AU  - H Tanaka
AU  - S Chen
AU  - Y Itow
AU  - T Kajita
AU  - R Nishijima
AU  - K Okumura
AU  - T Tashiro
AU  - T Tomiya
AU  - X Wang
AU  - F.J de Garay Arcones
AU  - P Fernandez
AU  - L Labarga
AU  - D Samudio
AU  - C Yanagisawa
AU  - B Jargowsky
AU  - E Kearns
AU  - J Mirabito
AU  - L Wan
AU  - T Wester
AU  - B.W Pointon
AU  - J Bian
AU  - B Cortez
AU  - N.J Griskevich
AU  - Y Jiang
AU  - M.B Smy
AU  - H.W Sobel
AU  - V Takhistov
AU  - J Hill
AU  - B.D Xu
AU  - D Jung
AU  - D.H Moon
AU  - R.G Park
AU  - B.S Yang
AU  - K Scholberg
PY  - 2026
DA  - 2026/09/26
PB  - HAL
DO  - 10.48550/arxiv.2609.25681
UR  - https://hal.science/hal-05780376v1
AB  - We report a new partial lifetime limit of 4.2 × 10^32 years for the trinucleon decay mode ^16O(ppp) → ^13C π^+ π^+ e^+, obtained from a search conducted using the Super-Kamiokande detector with 0.401 megaton-years of exposure across five operational periods (SK-I: 1996--2001, SK-II: 2002--2005, SK-III: 2006--2008, SK-IV: 2008--2018, SK-V: 2019--2020). This represents an improvement of six orders of magnitude over previous experimental constraints. The analysis utilizes a convolutional neural network (CNN) incorporating an attention mechanism---a computational technique that enables the model to focus on the most relevant regions of Cherenkov ring patterns---to enhance event classification, thereby improving the sensitivity of the search. This is the first application of a CNN to a nucleon decay search in Super-Kamiokande. Furthermore, the large dataset available in Super-Kamiokande (hereafter "SK") strengthens the statistical power of the study, enabling a more stringent constraint than those set by prior experiments.
ER  -