Exploring Fermionic Multiplet Dark Matter through Precision Measurements at the CEPC

TL;DR

This paper investigates how precision measurements at the CEPC can detect fermionic multiplet dark matter models through loop effects, providing complementary constraints on dark matter masses up to 150 GeV and 450 GeV.

Contribution

It calculates one-loop corrections for specific processes in two dark matter models and assesses their detectability at CEPC, offering new insights into dark matter parameter space.

Findings

Dark matter mass can be probed up to ~150 GeV and ~450 GeV.

Complementary sensitivity regions improve detection prospects.

Loop effects provide a viable indirect detection method.

Abstract

New physics could be explored through loop effects by the precision measurements at the Circular Electron Positron Collider due to its clean collision environment and high luminosity. In this work, we focus on two dark matter models that involve additional electroweak fermionic multiplets. We calculate their one-loop corrections to five processes, i.e. $e^+e^- \to \mu^+\mu^-, ~Zh, ~ZZ, ~W^+W^-$, and $Z\gamma$, and investigate the corresponding signatures at CEPC with the projected sensitivity. We find that the detectable parameter regions of these processes are complementary. The combined analysis shows that the mass of dark matter $m_{\chi^0_1}$ in these two models can be probed up to $ \sim 150~\mathrm{GeV}$ and $\sim 450$ GeV at a 95\% confidence level, respectively.