Exploring fermionic multiplet dark matter through precision measurements at the CEPC

Abstract：

New physics could be explored through loop effects using the precision measurements at the Circular Electron Positron Collider (CEPC) owing to its clean collision environment and high luminosity. In this paper, we focus on two dark matter models that involve additional electroweak fermionic multiplets. We calculate their one-loop corrections in five processes, i.e., $ e^+e^- \to \mu^+\mu^-, \; Zh, \; W^+W^-, \; ZZ $ , and $ Z\gamma $ , and investigate the corresponding signatures at the CEPC with the projected sensitivity. We observe 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\; {\rm{GeV}} $ and $ \sim 450 $ GeV, respectively, at a 95% confidence level.