PNNL

Abstract

The QCD (Quantum ChromoDynamics) axion emerged as one of the best-motiva-ted dark matter candidates. In 2018, the Axion Dark Matter eXperiment (ADMX), one of the U.S. Department of Energy’s “Gen 2” ?agship dark matter projects, demonstrated ?rst sensitivity to the highly-plausible “DFSZ” dark matter axion couplings over a small frequency range. We anticipate this development marks the ?rst step in constructing yet more powerful experiments that can explore large swaths of the axion parameter space at high sensitivity and result in a discovery. But, realizing this requires advances in both our understanding of the theory and experiment design.