Extinction Measurement at J-PARC MR with Slow-Extracted Pulsed Proton Beam for COMET Experiment

Noguchi Kyohei, Yuki Fujii, Yoshinori Fukao, Yoshinori Hashimoto, Yuya Higuchi, Ryotaro Honda, Yoichi Igarashi, Fumihito Ikeda, Satoshi Mihara, Ryotaro Muto, Yu Nakazawa, Hajime Nishiguchi, Kou Oishi, Masayoshi Shoji, Fumihiko Tamura, Junji Tojo, Masahito Tomizawa, Kazuki Ueno, Hisataka Yoshida

Research output: Contribution to journalConference articlepeer-review


The COMET experiment aims to search for the neutrinoless conversion of a muon to an electron in a muonic atom. This experiment utilizes a bunched slow-extracted (bunched-SX) proton beam at 8 GeV from the J-PARC main ring synchrotron. To achieve a sensitivity of 10−17, the fraction of inter-bunch stray protons, called extinction, must be less than 10−10. The 8 GeV proton beam commissioning with a bunched-SX beam for the COMET experiment was performed in May 2021. The extinction was measured by counting all secondary pions in the K1.8BR secondary beamline in the J-PARC Hadron Experimental Facility. After the extinction studies tried out several setups, the most extinction achievable setup was performed with O(1010) statistics. This paper reports the extinction measurement and the current analysis status.

Original languageEnglish
Article number104
JournalProceedings of Science
Publication statusPublished - Mar 31 2022
Event22nd International Workshop on Neutrinos from Accelerators, NuFact 2021 - Cagliari, Italy
Duration: Sept 6 2021Sept 11 2021

All Science Journal Classification (ASJC) codes

  • General


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