The 2025 International Workshop on the High Energy Circular Electron Positron Collider

In this talk, I will present a comprehensive study of Higgs boson production associated with a neutrino pair at $e^+ e^−$ colliders ($e^+ e^- \to h \nu \bar{\nu}$) at NLO electroweak (EW) accuracy in both the SM and the two-Higgs-doublet model (2HDM). I will show that new physics effects from the extended Higgs sector can be probed through EW corrections, which lead to deviations from the SM predictions reaching 6% to 7%. Even in the alignment limit, these deviations can still reach 2% to 3%, making them experimentally testable. This highlights the potential of precision studies at future $e^+ e^−$ colliders for searching new physics.