Axion Dark Matter

TL;DR

This paper reviews axion dark matter as a promising candidate, summarizes current and future experimental efforts for detection, and emphasizes the US's leading role in advancing axion research in the next decade.

Contribution

It provides a comprehensive overview of axion phenomenology and outlines next-generation experimental strategies for detecting axion dark matter.

Findings

Axions are viable dark matter candidates with strong theoretical motivation.

Next-generation experiments are being developed with advanced instrumentation.

The US is strategically positioned to lead axion dark matter searches.

Abstract

Axions are well-motivated dark matter candidates with simple cosmological production mechanisms. They were originally introduced to solve the strong CP problem, but also arise in a wide range of extensions to the Standard Model. This Snowmass white paper summarizes axion phenomenology and outlines next-generation laboratory experiments proposed to detect axion dark matter. There are vibrant synergies with astrophysical searches and advances in instrumentation including quantum-enabled readout, high-Q resonators and cavities and large high-field magnets. This white paper outlines a clear roadmap to discovery, and shows that the US is well-positioned to be at the forefront of the search for axion dark matter in the coming decade.