# The CP-symmetries of the 2HDM

## TL;DR

This paper classifies three types of CP-symmetries in the two-Higgs-doublet model and provides conditions to identify which symmetry is realized based on the model's masses and couplings.

## Contribution

It introduces a systematic way to verify the realization of CP-symmetries in the 2HDM using observable parameters.

## Key findings

- Conditions for CP1, CP2, and CP3 symmetries expressed in terms of masses and couplings.
- Method to determine the realized CP-symmetry in the 2HDM.
- Framework for experimental verification of CP-symmetries.

## Abstract

We discuss the three different classes of CP-symmetries that can be realized in a two-Higgs-doublet model, CP1, CP2 and CP3. We express conditions for realizing these symmetries in terms of masses and couplings of the model, thereby providing a way of verifying which, if any, of these symmetries is realized by nature.