Search for Invisible Axion Dark Matter in the $3.3–4.2  μeV$ Mass Range

We report the results from a haloscope search for axion dark matter in the $3.3–4.2 μeV$ mass range. This search excludes the axion-photon coupling predicted by one of the benchmark models of "invisible" axion dark matter, the Kim-Shifman-Vainshtein-Zakharov model. This sensitivity is achieved using a large-volume cavity, a superconducting magnet, an ultra low noise Josephson parametric amplifier, and sub-Kelvin temperatures. The validity of our detection procedure is ensured by injecting and detecting blind synthetic axion signals.