Searching for dilaton dark matter with atomic clocks

Understand

We propose an experiment to search for ultralight scalar dark matter (DM) with dilatonic interactions.

• Such couplings can arise for the dilaton as well as for moduli and axion-like particles in the presence of CP violation.
• Ultralight dilaton DM acts as a background field that can cause tiny but coherent oscillations in Standard Model parameters such as the fine structure constant and the proton-electron mass ratio.
• These minute variations can be detected through precise frequency comparisons of atomic clocks.