Heavy neutral leptons in gauged U(1) L µ −L τ at muon collider - He 何, Ru-Yi 如意; Huang 黄, Jia-Qi 佳琪; Xu 许, Jin-Yuan 金源; Yang 杨, Fa-Xin 法新; Han 韩, Zhi-Long 志龙; Shao 邵, Feng-Lan 凤兰 (Chinese physics C, 2024)