Abstract

Measurements of the muonic helium atom hyperfine structure (HFS) are a sensitive tool to test the theory of three-body atomic systems and bound-state quantum electrodynamics (QED) and to determine fundamental constants of the negative muon magnetic moment and mass. The world’s most intense pulsed negative muon beam at J-PARC MUSE brings an opportunity to improve previous measurements and test further CPT invariance by comparing the magnetic moments and masses of positive and negative muons. Test measurements at D-line are now in progress utilizing MuSEUM apparatus at zero field. The first results already have better accuracy than previous measurements in the 1980s. Also, the investigation of a new experimental approach to improve HFS measurements by repolarizing muonic helium atoms using a spin-exchange optical pumping (SEOP) technique was started. If successful, this would drastically improve the measurement accuracy.

Details

Title
Status of the new muonic helium atom HFS measurements at J-PARC MUSE
Author
Strasser, P 1 ; Fukumura, S 2 ; Ino, T 1 ; Iwai, R 1 ; Kanda, S 1 ; Kawamura, S 2 ; Kitaguchi, M 2 ; Nishimura, S 1 ; Oku, T 3 ; Okudaira, T 2 ; Seo, S 4 ; Shimizu, H M 2 ; Shimizu, K 5 ; Shimomura, K 1 ; Tada, H 2 ; Tanaka, T 4 ; Torii, H A 6 ; Yamauchi, H 5 ; Yasuda, H 6 

 Institute of Materials Structure Science (IMSS), High Energy Accelerator Research Organization (KEK) , 1-1 Oho, Tsukuba, Ibaraki 305-0801 , Japan; Materials and Life Science Division, J-PARC Center , 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195 , Japan 
 Department of Physics, Nagoya University , Furo-cho, Chikusa-ku, Nagoya 464-8601 , Japan 
 Materials and Life Science Division, J-PARC Center , Japan Atomic Energy Agency (JAEA), 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195 , Japan; Graduate School of Science and Engineering, Ibaraki University , 2-1-1 Bunkyo, Mito, Ibaraki 310-8512 , Japan 
 Graduate School of Arts and Sciences, The University of Tokyo , 3-8-1 Komaba, Meguro, Tokyo 153-8902 , Japan; Meson Science Laboratory, Nishina Center for Accelerator-Based Science , RIKEN, Hirosawa-2-1, Wako, Saitama 351-0198 , Japan 
 Graduate School of Arts and Sciences, The University of Tokyo , 3-8-1 Komaba, Meguro, Tokyo 153-8902 , Japan 
 School of Science, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 , Japan 
First page
012023
Publication year
2023
Publication date
Mar 2023
Publisher
IOP Publishing
ISSN
17426588
e-ISSN
17426596
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2793464362
Copyright
Published under licence by IOP Publishing Ltd. This work is published under http://creativecommons.org/licenses/by/3.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.