# CEPC Precision of Electroweak Oblique Parameters and Weakly Interacting Dark Matter: the Scalar Case

## TL;DR

This paper assesses how future CEPC measurements of electroweak parameters can detect or constrain scalar dark matter models, potentially surpassing current direct detection limits for certain parameter ranges.

## Contribution

It introduces a method to probe scalar dark matter via electroweak oblique parameters at CEPC, highlighting sensitivity improvements over existing experiments.

## Key findings

- CEPC can detect scalar dark matter up to 1 TeV mass.
- Electroweak oblique parameters are sensitive to scalar multiplet couplings.
- Potential to outperform current direct detection experiments.

## Abstract

We investigate the sensitivity to weakly interacting scalar dark matter from future determination of electroweak oblique parameters in the Circular Electron-Positron Collider (CEPC) project. As illuminating examples, three dark matter models with scalar electroweak multiplets are studied. The multiplet couplings to the standard model Higgs doublet can break the mass degeneracy among the components, leading to nonzero contributions to oblique parameters. The dark matter candidate in these model is either a CP-even or CP-odd scalar, whose trilinear coupling to the Higgs boson could induce direct detection signals. For some moderate coupling values, we find that the CEPC sensitivity can be better than current direct detection experiments, exploring up to a TeV mass scale.