X ray spectroscopy on 𝚵− atoms (J-PARC E03, E07 and future) Takeshi. O. Yamamoto, M. Fujita, T. Gogami, T. K. Harada, S. H. Hayakawa, K. Hosomi, Y. Ichikawa, Y. Ishikawa, K. Kamada, H. Kanauchi et al. (8 more) EPJ Web Conf., 271 (2022) 03001 Published online: 09 November 2022 DOI: 10.1051/epjconf/202227103001