A Search for Invisible Axion Dark Matter with the Axion Dark Matter Experiment

TL;DR

This paper reports a haloscope experiment that searches for invisible axion dark matter within a specific mass range, achieving unprecedented sensitivity and excluding certain theoretical models of axion-photon coupling.

Contribution

The study introduces a highly sensitive haloscope setup operating at sub-kelvin temperatures, enabling the exclusion of axion-photon couplings predicted by plausible invisible axion models.

Findings

Excluded axion-photon coupling range for 2.66-2.81 μeV mass

Achieved sensitivity surpassing previous experiments

Operated at sub-kelvin temperatures to reduce noise

Abstract

This Letter reports results from a haloscope search for dark matter axions with masses between 2.66 and 2.81 $\mu$eV. The search excludes the range of axion-photon couplings predicted by plausible models of the invisible axion. This unprecedented sensitivity is achieved by operating a large-volume haloscope at sub-kelvin temperatures, thereby reducing thermal noise as well as the excess noise from the ultra-low-noise SQUID amplifier used for the signal power readout. Ongoing searches will provide nearly definitive tests of the invisible axion model over a wide range of axion masses.