The study of high-efficiency pion production Weichao Yao, Masaharu Aoki, Chen Wu, Kou Oishi and Yoshinori Fukao Eur. Phys. J. Plus, 140 4 (2025) 267 Published online: 02 April 2025 DOI: 10.1140/epjp/s13360-025-06164-9