First results from a microwave cavity axion search at 24 micro-eV

Understand

We report on the first results from a new microwave cavity search for dark matter axions with masses above $20~\mu\text{eV}$.

• We exclude axion models with two-photon coupling $g_{a\gamma\gamma} \gtrsim 2\times10^{-14}~\text{GeV}^{-1}$ over the range $23.55~\mu\text{eV} < m_a < 24.0~\mu\text{eV}$.
• These results represent two important achievements.
• First, we have reached cosmologically relevant sensitivity an order of magnitude higher in mass than any existing limits.