https://doi.org/10.1140/epjp/s13360-026-07792-5
Regular Article
Probing strong first-order electroweak phase transition scenarios in two-Higgs-doublet model with FCC-ee/CEPC
1
Institute for Theoretical Physics, Karlsruhe Institute of Technology, 76131, Karlsruhe, Germany
2
Institute for Astroparticle Physics, Karlsruhe Institute of Technology, 76344, Eggenstein-Leopoldshafen, Germany
3
Deutsches Elektronen-Synchrotron DESY, 22607, Hamburg, Germany
4
Department of Physics and Astronomy, University of Manchester, M13 9PL, Manchester, UK
a
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Received:
27
March
2026
Accepted:
6
May
2026
Published online:
26
May
2026
Abstract
We investigate the potential of future electron–positron colliders, such as FCC-ee and CEPC, to test a strong first-order electroweak phase transition (SFOEWPT) in the CP-conserving type I two-Higgs-doublet model. We confront the SFOEWPT-favored parameter space with projected electroweak precision and Higgs measurements, as well as searches for additional scalar states. We show that radiative corrections to 
production can generate deviations in the cross section that exceed the anticipated sub-percent precision at lepton colliders, even when LHC and Z-pole measurements remain consistent with the SM. Precision Higgs-strahlung measurements therefore provide an indirect and sensitive probe of electroweak-scale BSM effects.\query{Please check the edit made in the article title.}
Talk based on [1], presented at the International Workshop on Future Linear Colliders (LCWS 2025), 20–24 October 2025, Valencia, Spain.
© The Author(s) 2026
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