Exploring Fermionic Dark Matter via Higgs Boson Precision Measurements at the Circular Electron Positron Collider

TL;DR

This paper investigates how future Higgs boson measurements at the CEPC can reveal properties of fermionic dark matter, especially through loop and tree-level effects, offering complementary insights to existing detection methods.

Contribution

It introduces a detailed analysis of fermionic dark matter impacts on Higgs precision measurements at the CEPC, including two UV-complete models and their experimental sensitivities.

Findings

CEPC can probe certain dark matter parameter regions beyond current searches.

Higgs measurements provide complementary constraints to direct detection.

Loop and tree-level effects significantly influence Higgs observables.

Abstract

We study the impact of fermionic dark matter (DM) on projected Higgs precision measurements at the Circular Electron Positron Collider (CEPC), including the one-loop effects on the $e^+e^-\to Zh$ cross section and the Higgs boson diphoton decay, as well as the tree-level effects on the Higgs boson invisible decay. As illuminating examples, we discuss two UV-complete DM models, whose dark sector contains electroweak multiplets that interact with the Higgs boson via Yukawa couplings. The CEPC sensitivity to these models and current constraints from DM detection and collider experiments are investigated. We find that there exist some parameter regions where the Higgs measurements at the CEPC will be complementary to current DM searches.