Complex Dark Photon Dark Matter EFT

TL;DR

This paper develops an effective field theory framework for complex dark photon dark matter, incorporating operators up to dimension six, and applies it to collider and direct detection constraints, emphasizing electric dipole interactions.

Contribution

It introduces a systematic EFT construction for complex dark photon dark matter, including a novel power counting scheme and extended operator analysis for detection experiments.

Findings

Properly accounts for non-renormalizable interactions with smaller Wilson coefficients.

Derives scaling limits for collider bounds on light dark matter.

Highlights electric dipole interactions as key signatures.

Abstract

We construct an effective field theory for complex Stueckelberg dark photon dark matter. Such an effective construction can be realized by writing down a complete set of operators up to dimension six built with the complex dark photon and Standard Model fields. Classifying the effective operators, we find that in order to properly take into account the non-renormalizable nature of an interacting massive vector, the size of the Wilson coefficients should be naturally smaller than naively expected. This can be consistently taken into account by a proper power counting, that we suggest. First we apply this to collider bounds on light dark matter, then to direct detection searches by extending the list of non-relativistic operators to include the case of complex vectors. In the former we correctly find scaling limits for small masses, while in the latter we mostly focus on electric dipole interactions, that are the smoking gun of this type of dark matter. Simple UV completions that effectively realize the above scenarios are also outlined.