Search for axion dark matter at IBS/CAPP
The axion, a consequence of the PQ mechanism proposed to solve the strong-CP problem of particle physics, has been considered as a compelling candidate for cold dark matter. The Center for Axion and Precision Physics Research (CAPP) of the Institute for Basic Science (IBS) has been establishing state-of-the-art axion search experiments in Korea since 2013. Relying on the haloscope technique, where axions are resonantly converted into microwave photons in a strong magnetic field, our strategy is to run multiple experiments in parallel to explore a large area of the axion parameter space. The ultimate goal is to probe axion dark matter in the mass range up to 40\,$\mu$eV with sensitivities of the QCD axion models. The current approaches to achieve this goal are twofold: 1) utilizing well-advanced technologies, including high field superconducting (SC) magnets, cryogenic dilution refrigerators, quantum-limited noise amplifiers, and 2) developing unique features, such as high-$Q$ SC cavities under high magnetic fields, and efficient cavity design for high-frequency axion search. We present the status and future prospects of the experiments and discuss the R\&D activities at IBS/CAPP.