Abstract
We report on a search for ultralow-mass axionlike dark matter by analyzing the ratio of the spin-precession frequencies of stored ultracold neutrons and atoms for an axion-induced oscillating electric dipole moment of the neutron and an axion-wind spin-precession effect. No signal consistent with dark matter is observed for the axion mass range . Our null result sets the first laboratory constraints on the coupling of axion dark matter to gluons, which improve on astrophysical limits by up to 3 orders of magnitude, and also improves on previous laboratory constraints on the axion coupling to nucleons by up to a factor of 40.
- Received 29 August 2017
DOI:https://doi.org/10.1103/PhysRevX.7.041034
Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.
Published by the American Physical Society
Physics Subject Headings (PhySH)
Synopsis
New Constraints on Axion-Gluon Interaction Strength
Published 14 November 2017
An analysis of spin-precession data of atoms and neutrons sets some of the tightest limits to date on the strength of interactions between axions and gluons or nucleons.
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Popular Summary
Astrophysical observations indicate that about 95% of all matter and energy in the Universe is composed of “invisible” forms known as dark matter and dark energy, whose nature remains unknown. A promising candidate for dark matter is axions, hypothetical particles of very low mass and high abundance. Axions interact with ordinary matter in ways that are distinct from those of other candidates. So far, most searches for axions have been based on electromagnetic interactions and target axions in the gigahertz frequency range. In contrast, we searched for axions in the nano- to millihertz range—frequencies that are out of reach for those other methods. Although our search ended with a null result, it provides the first laboratory constraints on the coupling of axion dark matter to gluons, improving on astrophysical limits by up to 3 orders of magnitude. Moreover, our results tighten previous laboratory limits on the axion coupling to nucleons by a factor of up to 40.
We looked for signatures stemming from the interactions of axions with nucleons and the gluons therein. Our search is based on interactions that are predicted to induce harmonic oscillations in the electric dipole moment (EDM) and energy levels of the neutron and of atoms. The best neutron EDM measurement so far comes from an experiment at the Institut Laue-Langevin in Grenoble, France, whereas the currently most sensitive experiment is ongoing at the Paul Scherrer Institute in Villigen, Switzerland. We used data from both of these experiments and searched for time variations caused by axion dark matter.
The fact that we saw no signal consistent with the presence of axions places tight constraints on the interaction strengths for ultralow-mass axionlike dark matter and should help to guide both future searches and model refinement.