First Results from an Axion Haloscope at CAPP around 10.7  μeV

Area of Science:

• Particle Physics
• Cosmology
• Astrophysics

Background:

• Dark matter constitutes a significant portion of the universe's mass.
• Axions are hypothetical elementary particles proposed as a dark matter candidate.
• Ultralow temperature microwave resonators offer a sensitive method for detecting axions.

Purpose of the Study:

• To search for axion dark matter within specific mass ranges.
• To establish new exclusion limits for axion properties.
• To demonstrate the efficacy of ultralow temperature resonators in axion detection.

Main Methods:

• Utilizing the Center for Axion and Precision Physics Research's experimental setup.
• Employing ultralow temperature microwave resonators operating below 40 mK.
• Analyzing data to exclude axion mass ranges with specific coupling sensitivities.

Main Results:

• Exclusion of the axion mass range 10.7126–10.7186 μeV with near Kim-Shifman-Vainshtein-Zakharov (KSVZ) coupling sensitivity.
• Exclusion of the axion mass range 10.16–11.37 μeV with approximately 9 times larger coupling at 90% confidence level.
• Achieved the lowest resonator physical temperature for an axion search to date.

Conclusions:

• The study provides the first axion search results in the reported mass ranges.
• The experiment demonstrates significant progress in axion detection sensitivity and temperature thresholds.
• These findings contribute to narrowing down the parameter space for axion dark matter.