Displaced heavy neutral lepton from new Higgs doublet Fa-Xin Yang, Feng-Lan Shao, Zhi-Long Han, Yi Jin and Honglei Li Eur. Phys. J. C, 85 4 (2025) 401 Published online: 09 April 2025 DOI: 10.1140/epjc/s10052-025-14125-w