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

TL;DR

This paper assesses how future CEPC measurements could enhance constraints on electroweak parameters and detect weakly interacting fermionic dark matter, especially in models with custodial symmetry, surpassing some direct detection limits.

Contribution

It provides a detailed analysis of CEPC's potential to probe TeV-scale dark matter models via electroweak precision data, highlighting regions inaccessible to direct detection.

Findings

CEPC can probe dark matter models up to TeV scales.

Electroweak precision data can explore parameter regions beyond direct detection.

Custodial symmetry models are particularly well constrained.

Abstract

Future electroweak precision measurements in the Circular Electron Positron Collider (CEPC) project would significantly improve the precision of electroweak oblique parameters. We evaluate the expected precision through global fits, and study the corresponding sensitivity to weakly interacting fermionic dark matter. Three models with electroweak multiplets in the dark sector are investigated as illuminating examples. We find that the CEPC data can probe up to TeV scales and explore some regions where direct detection cannot reach, especially when the models respect the custodial symmetry.