Preliminary ADMX Run1D Results

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 may 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. With help from a dilution refrigerator and from ultra low noise quantum amplifiers, ADMX has achieved the sensitivity required for discovering both Kim–Shifman–Vainshtein–Zakharov (KSVZ) and Dine-Fischler-Srednicki-Zhitnitsky (DFSZ) benchmark axion models, for O(1) µeV axion masses. In this talk, I will report the result of the recent data taking run at AMDX, exploring more than 100 MHz new parameter space around 5 µeV with KSVZ axion discovery ability.