Search for QCD axion dark matter around 24.5 µeV using an 8-cell microwave resonant cavity haloscope and a flux-driven Josephson parametric amplifier

Abstract

Axion, a hypothetical particle originally emerging from a proposed solution to the strong CP problem of particle physics, is one of the favored candidates addressing the dark matter puzzle. As part of the efforts within the Center for Axion and Precision Physics Research of the Institute for Basic Science, we are searching for axion dark matter using the haloscope method sensitive to masses around 24.5 µeV at Kim-Shifman-Vainshtein-Zakharov (KSVZ) sensitivity. A unique 8-cell cavity, used for the first time in search of KSVZ axions, is cooled down to 40 mK within a magnetic field of 8 T. The expected axion signal resonating with the TM