Constraining exotic spin dependent interactions of muons and electrons H. Yan, G. A. Sun, S. M. Peng, H. Guo, B. Q. Liu, M. Peng and H. Zheng Eur. Phys. J. C, 79 11 (2019) 971 Published online: 25 November 2019 DOI: 10.1140/epjc/s10052-019-7442-8