Search for axion dark matter at IBS/CAPP

Abstract

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 µeV 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.