Quantification of bulk elemental composition for C-type asteroid Ryugu samples with nondestructive elemental analysis using muon beam

Ninomiya, Kazuhiko*; Osawa, Takahito; Terada, Kentaro*; Wada, Taiga*; Nagasawa, Shunsaku*; Chiu, I.-H.; Nakamura, Tomoki*; 40 of others*

Meteoritics & Planetary Science, 59(8), p.2044 - 2057, 2024/08

https://doi.org/10.1111/maps.14135

Samples from asteroid Ryugu, brought back by asteroid explorer Hayabusa2 are important for investigating the origin and evolution of the solar system. Here, we report the elemental compositions of a 123 mg Ryugu sample determined with a nondestructive muon elemental analysis method. This method is a powerful tool for determining bulk chemical composition, including light elements such as C, N, and O. From the muonic X-ray spectra with three carbonaceous chondrites, the relationship between the elemental composition and muonic X-ray intensity was determined for each element. Calibration curves showed linearity, and the elemental composition of Ryugu was quantitatively determined. The results reflect the average bulk elemental composition of asteroid Ryugu owing to the large amount of samples. Ryugu has an elemental composition similar to that of Orgueil (CI1), and should be classified as CI1. However, the O/Si ratio of Ryugu is 25% lower than that of Orgueil, indicating that Orgueil may have been seriously contaminated by terrestrial materials after its fall to Earth. These results indicate that the Ryugu sample is more representative than the CI chondrites as a solid material of the solar system.

Laser-assisted decay spectroscopy for the ground states of Au

Harding, R. D.*; Andreyev, A. N.; Barzakh, A. E.*; Atanasov, D.*; Cubiss, J. G.*; Van Duppen, P.*; 40 of others*

Physical Review C, 102(2), p.024312_1 - 024312_16, 2020/08

https://doi.org/10.1103/PhysRevC.102.024312

Search for excited state of hypernucleus in the J-PARC E13 experiment

Nakagawa, Manami*; Ekawa, Hiroyuki; Hasegawa, Shoichi; Hayakawa, Shuhei; Hosomi, Kenji; Hwang, S.; Ichikawa, Yudai; Imai, Kenichi; Sako, Hiroyuki; Sato, Susumu; et al.

JPS Conference Proceedings (Internet), 17, p.012009_1 - 012009_4, 2017/07

https://doi.org/10.7566/JPSCP.17.012009

Dielectron production in Au + Au collisions at = 200 GeV

Adare, A.*; Hasegawa, Shoichi; Imai, Kenichi; Nagamiya, Shoji; Sako, Hiroyuki; Sato, Susumu; Tanida, Kiyoshi; PHENIX Collaboration*; 440 of others*

Physical Review C, 93(1), p.014904_1 - 014904_34, 2016/01

AA2015-0856.pdf:3.7MB

https://doi.org/10.1103/PhysRevC.93.014904