Testing CP-violation in a heavy Higgs sector at CLIC Kingman Cheung, Ying-nan Mao, Stefano Moretti and Rui Zhang Eur. Phys. J. C, 85 6 (2025) 700 Published online: 25 June 2025 DOI: 10.1140/epjc/s10052-025-14369-6