The search for low-mass axion dark matter with ABRACADABRA-10cm

TL;DR

This paper reports on a highly sensitive search for low-mass axion dark matter using the ABRACADABRA-10cm experiment, setting new upper limits on axion-photon coupling in the 0.41-8.27 neV mass range.

Contribution

The study introduces the first broadband ABRACADABRA-10cm experiment results with world-leading sensitivity, constraining axion-photon coupling in a key mass range for dark matter.

Findings

No evidence for axions was found.

Set 95% upper limits on axion-photon coupling at $g_{a o ext{γγ}}<3.2 imes10^{-11}$ GeV$^{-1}$.

Established the most sensitive constraints in the 0.41 - 8.27 neV mass range.

Abstract

Two of the most pressing questions in physics are the microscopic nature of the dark matter that comprises 84% of the mass in the universe and the absence of a neutron electric dipole moment. These questions would be resolved by the existence of a hypothetical particle known as the quantum chromodynamics (QCD) axion. In this work, we probe the hypothesis that axions constitute dark matter, using the ABRACADABRA-10cm experiment in a broadband configuration, with world-leading sensitivity. We find no significant evidence for axions, and we present 95% upper limits on the axion-photon coupling down to the world-leading level $g_{a\gamma\gamma}<3.2 \times10^{-11}$ GeV$^{-1}$, representing one of the most sensitive searches for axions in the 0.41 - 8.27 neV mass range. Our work paves a direct path for future experiments capable of confirming or excluding the hypothesis that dark matter is a QCD axion in the mass range motivated by String Theory and Grand Unified Theories.