Daniel: Modified Theories of Gravity, Parity, and the Dark Sector / Zhang: Improved understanding of Josephson Parametric Amplifier responses at Axion Dark Matter eXperiment

Speaker: Tatsuya Daniel (Brown University) / Dan Zhang (University of Washington) In Person and zoom 

Zoom info: https://stanford.zoom.us/j/98604058568

Zhang: The existence of QCD axion is strongly motivated as a dynamical solution to the strong CP problem. By either the misalignment mechanism or by topological defect decays in the early universe, QCD axions can be the primary constituent of cold dark matter, which contributes 85% of the total mass in the standard cosmology. The Axion Dark Matter eXperiment (ADMX) is a pioneer QCD axion dark matter search experiment based on the Sikivie-type haloscope. Unprecedented sensitivity has been achieved to the benchmark models after implementing Josephson Parametric Amplifier (JPA) at ADMX, for O(1) µeV axion masses. Understanding the JPA responses in the receiver chain becomes important. In this talk, I will review ADMX and focus on the studies of the JPA responses at ADMX in the 2022 run and the current run.