# A Fermionic bi-Doublet Effective Field Theory for Dark Matter

## TL;DR

This paper develops an effective field theory with two fermionic doublets in the dark sector, showing that a WIMP at the electroweak scale can be consistent with data if it has magnetic dipole interactions.

## Contribution

It introduces a fermionic bi-doublet effective field theory for dark matter, highlighting the importance of magnetic dipole interactions for collider and astrophysical consistency.

## Key findings

- Electroweak scale WIMP is viable with magnetic dipole interactions.
- Dark sector interacts via renormalizable and non-renormalizable operators.
- Compatibility with collider and astrophysical data depends on dipole interactions.

## Abstract

We study an effective field theory which includes the Standard Model extended by a Dark Sector consisting of two fermionic $SU(2)_{L}$-doublets. A $Z_2$ parity guarantees that, after electroweak symmetry breaking, the lightest neutral particle is stable, acting as a WIMP. The dark sector interacts with the Higgs and gauge bosons through renormalizable and non-renormalizable $d=5$ operators. We find that a WIMP with a mass around the electroweak scale, i.e. accessible at the LHC, is consistent with collider and astrophysical data only when non-trivial magnetic dipole interactions with the gauge bosons exist.