First Search for Dark Photon Dark Matter with a madmax Prototype.

Area of Science:

• Particle Physics
• Cosmology
• Experimental Physics

Background:

• Dark matter remains a significant mystery in cosmology.
• Dark photons are a compelling theoretical candidate for dark matter particles.
• Previous experimental constraints on dark photon properties were limited.

Purpose of the Study:

• To conduct the first dark matter search using a dielectric haloscope prototype for the MADMAX experiment.
• To probe dark photon dark matter in the mass range of 78.62 to 83.95 μeV/c².
• To set new exclusion limits on the dark photon to photon mixing parameter (χ).

Main Methods:

• Utilized a dielectric haloscope prototype with sapphire disks and a mirror to convert dark photons to detectable photons.
• Employed a low-noise receiver and antenna to detect the converted photons.
• Analyzed data for signals exceeding expected background noise.

Main Results:

• No significant signal attributable to dark photon dark matter was observed.
• Established new exclusion limits for the dark photon to photon mixing parameter (χ).
• Excluded χ > 2.7 × 10⁻¹² across the full mass range and χ > 1.1 × 10⁻¹³ at 80.57 μeV/c² (95% confidence level).

Conclusions:

• The MADMAX prototype experiment has successfully set the most stringent limits on dark photon dark matter in the specified mass range.
• These results significantly improve upon previous constraints by up to three orders of magnitude.
• The findings pave the way for future, more sensitive searches for dark photon dark matter.