https://doi.org/10.1140/epjc/s10052-025-14369-6
Regular Article - Theoretical Physics
Testing CP-violation in a heavy Higgs sector at CLIC
1
Department of Physics and CTC, National Tsing Hua University, 300, Hsinchu, Taiwan
2
Division of Quantum Phases and Devices, School of Physics, Konkuk University, 143-701, Seoul, Republic of Korea
3
Department of Physics, School of Physics and Mechanics, Wuhan University of Technology, 430070, Wuhan, Hubei, China
4
School of Physics and Astronomy, University of Southampton, SO17 1BJ, Southampton, UK
5
Department of Physics and Astronomy, Uppsala University, Box 516, 751 20, Uppsala, Sweden
6
Theoretical Physics Division, Institute of High Energy Physics, 100049, Beijing, China
7
Shanghai Key Laboratory of Deep Space E.ploration Technology, Shanghai Institute of Satellite Engineering, No.3666 Yuanjiang Road, 201109, Shanghai, China
Received:
6
October
2024
Accepted:
26
May
2025
Published online:
25
June
2025
We propose a method for probing CP-violation in the heavy (pseudo)scalar sector of an extended Higgs model, in which we make simultaneous use of the HVV (
) and 
interactions of a heavy Higgs state H. The CP-even component of H can be probed through the tree-level HVV interaction, while the CP-odd component of H can be probed if the final 
pair can be tested to form a 
state. We can then confirm CP-violation if both CP-even and CP-odd components of H are discovered. This is possible at the Compact Linear Collider (CLIC) by exploiting H production from vector-boson fusion (VBF) and decay to pairs. We analyze the distribution of the azimuthal angle between the leptons coming from top and antitop quarks, which allows one to disentangle the CP nature of such a heavy Higgs state. We also show its implications for the two-Higgs-doublet model (2HDM) with CP-violation.
© The Author(s) 2025
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