Constraints on axion-like dark matter from a SERF comagnetometer.

Area of Science:

• Particle Physics and Cosmology
• Dark Matter Detection

Background:

• Ultralight axion-like particles are theoretical candidates for cosmological dark matter.
• These particles could generate time-dependent magnetic fields, offering a potential detection signature.
• Existing astrophysical bounds on axion-like particle couplings are robust but can be complemented by terrestrial searches.

Purpose of the Study:

• To establish terrestrial bounds on the coupling of axion-like particles to neutrons and protons.
• To explore the parameter space of axion-like dark matter within a specific mass range using a novel detector.
• To surpass existing astrophysical and terrestrial constraints for these couplings.

Main Methods:

• Utilized the Noble And Alkali Spin Detectors for Ultralight Coherent darK matter (NASDUCK) collaboration's detector.
• Employed noble-gas and alkali-metal atomic nuclei within a Spin-Exchange Relaxation-Free (SERF) regime for high sensitivity.
• Conducted a month-long experimental search targeting axion-like dark matter fields.

Main Results:

• Established new terrestrial bounds for axion-like particle couplings to protons and neutrons in the mass range of 1.4 × 10^-12 eV/c² to 2 × 10^-10 eV/c².
• Achieved limits that supersede astrophysical bounds and improve previous terrestrial constraints by up to two orders of magnitude.
• Provided the first reliable terrestrial bounds on proton couplings to axion-like dark matter, probing previously unexplored parameter space.

Conclusions:

• The NASDUCK experiment has successfully constrained ultralight axion-like particle couplings, significantly advancing terrestrial dark matter searches.
• The results highlight the potential of SERF magnetometers for sensitive detection of axion-like dark matter.
• This study opens new avenues for exploring axion-like dark matter interactions with standard model particles.