CP violation angles from H$\toττ$ decays at FCC-ee

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Authors: S. Giappichini, M. Klute, M. Presilla
Cited by: 0

Abstract

Measuring charge-parity (CP) violation in Higgs-fermion interactions is a key target of future precision Higgs programs. The decay $H\toττ$ is particularly sensitive to the CP structure of the Higgs Yukawa coupling via $τ$ spin correlation, while the clean environment of $e^+e^-$ collisions at the Future Circular Collider (FCC) enables accurate reconstruction of CP-sensitive observables. In this letter, we study the sensitivity of FCC-ee to the Higgs CP state using $H\toττ$ events produced in associated $ZH$ production at $\sqrt{s}=240$ GeV. In the anomalous-coupling parametrization, we project a precision of $Δϕ_{ττ}=\pm 2.5^\circ$ at 68 % CL, with the dominant contribution arising from one-prong hadronic $τ$ decays. We further interpret the analysis in the Effective Field Theory framework, deriving expected limits on the CP-odd operators, and compare them with electron and magnetic dipole moment measurements and the anomalous-coupling approach.

Fields of Study & Subjects

Particle physics theoretical and experimental studies Quantum Chromodynamics and Particle Interactions Particle Detector Development and Performance

Publication details

Journal / source
arXiv (Cornell University)
Publication date
6 February 2026
Language
EN
Document type
Preprint