The 1st IReNA-Ukakuren Joint Workshop “Advancing Professional Development in Nuclear Astrophysics and Beyond”

Nuclear reactions related to very high and ultra-high energy cosmic rays

1 Sept 2023, 11:30

40m

Large Seminar Room (Subaru Building) (NAOJ (National Astronomical Observatory of Japan))

Invited talk High Energy Astrophysics

Speaker

Eiji Kido (Astrophysical Big Bang Laboratory, RIKEN)

Description

The composition of very high-energy (VHE) and ultra-high energy (UHE) cosmic rays (CRs) was recently measured with higher statistics than before. The results implied that the composition of VHECRs becomes heavier up to $\sim {10}^{17.2}$ eV and lighter above the energy, and the composition of UHECRs becomes lighter up to $\sim {10}^{18.3}$ eV and heavier above the energy. The experimental evidence induces motivation to study the nuclear reactions of cosmic ray nuclei at the cosmic ray sources, in their propagation, and in the atmosphere of Earth. In this presentation, I will begin with an overview of the observations of very high and ultra-high energy cosmic rays and the nuclear reactions. After that, I will talk about our recent activities related to this topic.