Probing the CP property of ALP-photon interactions at future lepton colliders
4 affiliations
- 1Peking University
- 2School of Physics and Astronomy, Beijing Normal University, and Key Laboratory of Multiscale Spin Physics (Beijing Normal University), Ministry of Education
- 3South China Normal University
- 4Guangdong Basic Research Center of Excellence for Structure and Fundamental Interactions of Matter, Guangdong Provincial Key Laboratory of Nuclear Science
Abstract
A bstract : We investigate a charge-parity (CP) odd axion-like particle (ALP) featuring simultaneous CP-conserving (aFμ ν F̃μ ν ) and CP-violating ( aF μν F μν ) ALP–photon interactions at future lepton colliders. The ALP signal is studied in the process e ⁺ e − → e ⁺ e − a → e ⁺ e − γγ , where the CP structure of the interaction can be probed using the azimuthal angle difference between the final-state electrons, ∆ ϕ ee . We show that the projected sensitivity to the ALP–photon couplings can reach 𝒪(10 − 3 ) TeV − 1 , exceeding current constraints from the electron electric dipole moment ( e EDM). Because purely CP-conserving, purely CP-violating, and mixed interactions generate distinct ∆ ϕ ee distributions, a binned likelihood analysis of this observable enables an efficient discrimination of the ALP interaction structure. In particular, if the CP-conserving and CP-violating couplings are comparable — as motivated by possible symmetry considerations — the interference pattern in the ∆ ϕ ee distribution allows future lepton colliders to identify CP violation in the ALP sector once a signal is observed. For scenarios where the two couplings differ significantly, increasing the integrated luminosity substantially improves the sensitivity to CP-violating effects.
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BibTeX
@article{ding2026probing,
title = {{Probing the CP property of ALP-photon interactions at future lepton colliders}},
author = {Jian-Nan Ding and Yandong Liu and Muyuan Song},
journal = {Journal of High Energy Physics},
year = {2026},
month = oct,
doi = {10.1007/jhep10(2026)148},
url = {https://link.springer.com/article/10.1007/JHEP10(2026)148},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Probing the CP property of ALP-photon interactions at future lepton colliders
AU - Jian-Nan Ding
AU - Yandong Liu
AU - Muyuan Song
PY - 2026
DA - 2026/10/14
JO - Journal of High Energy Physics
DO - 10.1007/jhep10(2026)148
UR - https://link.springer.com/article/10.1007/JHEP10(2026)148
AB - A bstract : We investigate a charge-parity (CP) odd axion-like particle (ALP) featuring simultaneous CP-conserving (aF_μ ν F̃^μ ν ) and CP-violating ( aF μν F μν ) ALP–photon interactions at future lepton colliders. The ALP signal is studied in the process e ⁺ e − → e ⁺ e − a → e ⁺ e − γγ , where the CP structure of the interaction can be probed using the azimuthal angle difference between the final-state electrons, ∆ ϕ ee . We show that the projected sensitivity to the ALP–photon couplings can reach 𝒪(10 − 3 ) TeV − 1 , exceeding current constraints from the electron electric dipole moment ( e EDM). Because purely CP-conserving, purely CP-violating, and mixed interactions generate distinct ∆ ϕ ee distributions, a binned likelihood analysis of this observable enables an efficient discrimination of the ALP interaction structure. In particular, if the CP-conserving and CP-violating couplings are comparable — as motivated by possible symmetry considerations — the interference pattern in the ∆ ϕ ee distribution allows future lepton colliders to identify CP violation in the ALP sector once a signal is observed. For scenarios where the two couplings differ significantly, increasing the integrated luminosity substantially improves the sensitivity to CP-violating effects.
SN - 1029-8479
ER -