Advances in direct measurements of cosmic rays

Abstract

In celebration of the 25th anniversary of the Korean Physical Society Astrophysics Division, reflecting on the progress in cosmic-ray astrophysics seems worthwhile. Significant advances have been made in cosmic-ray measurements in recent years, particularly with successful space missions and long-duration balloon flights over Antarctica. The high precision data from these missions over a wide energy range led to surprising new discoveries, such as an excess of positrons at high energies and hardening of the elemental spectra. These unexpected spectral features present significant challenges for Galactic cosmic-ray models on their origin, propagation, and acceleration. This paper focuses on a few key findings, discussing direct measurements of cosmic rays from space-based and high-altitude balloon-borne experiments.