Discovering QCD-Coupled Axion Dark Matter with Polarization Haloscopes

TL;DR

This paper proposes a polarization haloscope method to detect QCD axion dark matter by observing induced electric dipole moments in atoms, offering a new way to explore axion parameter space and confirm potential signals.

Contribution

It introduces a novel polarization haloscope technique that can probe QCD-coupled axions with existing technology and distinguish QCD axions from other axion-like particles.

Findings

Existing technology can explore new axion parameter space.

The method can confirm if detected signals are from QCD axions.

Potential to test axion-photon coupling signals for QCD origin.

Abstract

In the presence of QCD axion dark matter, atoms acquire time-dependent electric dipole moments. This effect gives rise to an oscillating current in a nuclear spin-polarized dielectric, which can resonantly excite an electromagnetic mode of a microwave cavity. We show that with existing technology such a "polarization haloscope" can explore orders of magnitude of new parameter space for QCD-coupled axions. If any cavity haloscope detects a signal from the axion-photon coupling, an upgraded polarization haloscope has the unique ability to test whether it arises from the QCD axion.