# Effect of CP violation in the singlet-doublet dark matter model

## TL;DR

This paper explores how CP violation in the singlet-doublet dark matter model induces pseudoscalar interactions that help evade direct detection constraints and remains consistent with observed dark matter density, with testable electric dipole moment predictions.

## Contribution

It demonstrates that CP violation introduces pseudoscalar interactions in the dark matter model, allowing it to satisfy relic density constraints while evading direct detection bounds.

## Key findings

- Pseudoscalar interactions help evade direct detection constraints.
- The model explains the observed dark matter density.
- Electron EDM is a promising test for the model.

## Abstract

We revisit the singlet-doublet dark matter model with a special emphasis on the effect of CP violation on the dark matter phenomenology. The CP violation in the dark sector induces a pseudoscalar interaction of a fermionic dark matter candidate with the SM Higgs boson. The pseudoscalar interaction helps the dark matter candidate evade the strong constraints from the dark matter direct detection experiments. We show that the model can explain the measured value of the dark matter density even if dark matter direct detection experiments do not observe any signal. We also show that the electron electric dipole moment is an important complement to the direct detection for testing this model. Its value is smaller than the current upper bound but within the reach of future experiments.