Speaker
Description
The μeV-mass axion is one of the most promising candidates for cold dark matter and remains to be a well-motivated solution to the CP problem of quantum chromodynamics (QCD) via the Peccei-Quinn mechanism. In this paper, we propose a novel method to detect the dark-matter axions in our Galaxy via the resonant emission |e⟩→|g⟩+γ+γ′+a (or the absorption a+|e⟩→|g⟩+γ+γ′) in an atomic system with superradiance, where |e⟩ and |g⟩ stand for the excited and ground energy levels of atoms, respectively. A similar process via |e⟩→|g⟩+γ+a (or a+|e⟩→|g⟩+γ) is also put forward to probe the axion-electron coupling. For the nominal experimental setup assuming a background-free environment, most of the parameter space for typical QCD axion models can be covered with parahydrogen molecules or ytterbium atoms.
