# Signature of 2HDM at Higgs Factories

## TL;DR

This paper calculates one-loop electroweak and QED corrections to Higgs production in the 2HDM at future electron-positron colliders, highlighting potential measurable deviations from the Standard Model predictions.

## Contribution

It provides the first detailed one-loop correction analysis for $e^+ e^- o Z o ext{Higgs}$ processes in the 2HDM, including benchmark scenarios for future collider tests.

## Key findings

- Corrections are sizeable and potentially measurable at future colliders.
- Deviations from the Standard Model can be significant in certain benchmark scenarios.
- Electroweak and real emission effects are crucial for precise predictions.

## Abstract

The full one-loop corrections, both the weak and QED corrections, to the process $e^+ e^- \to Z \phi $ ($\phi=h^0,H^0$) in the two Higgs doublet model (2HDM) at the Higgs factories are presented. Up to the $O(\alpha_{em})$ level, the virtual corrections are evaluated by using the FeynArts/FormCalc packages. The real emission corrections are computed using the Feynman Diagram Calculation (FDC) package and the collinear divergences are regularized by the structure functions of an electron. Using the FeynArts/FormCalc and the FDC packages, we study the corrections in the Standard Model (SM) and the 2HDM, respectively. Gauge dependence arising in the normalization of mixing angles is removed by using the pinch technique. After taking into account experimental constraints from the current LHC data, we propose four interesting benchmark scenarios for future colliders. By using these benchmark scenarios, we evaluate the deviation of $\Delta\sigma(e^+ e^- \to Z \phi)$ from their SM values. We also examine Higgs boson decays $\phi\to b\bar{b}$ and $\phi\to \tau^+\tau^-$, which can have large electroweak (EW) contributions from triple Higgs couplings which are absent in the SM. It is found that for these benchmark scenarios, both EW and real emission corrections are sizeable and could be measured at a future $e^+ e^-$ colliders such as the ILC, CLIC, and CEPC.