Abstract: ADMX: An Ultra-Sensitive RF-Cavity Search for Axsion Dark-Matter

The axion is a hypothetical elementary particle whose existence would explain the baffling absence of CP violation in strong interactions. It also happens to be a good dark-matter candidate. Even if dark-matter axions made up the overwhelming majority of mass in the universe, they would be extraordinarily difficult to detect. However, by threading a high-Q microwave cavity with a large magnetic field, nearly Milky-Way halo axions would convert into micwowave photons within the cavity. This extremely tiny power, less than a yoctowatt, would then be detected by ultra-sensitive electromagnetic receivers. The sensitivity of this technique has improved to where even the more pessimistically-coupled dark-matter axions could be detected. This RPM will describe the progress our ADMX collaboration has made in this search for dark-matter axions.