Mr. N. J. Ayres on behalf of the PSI nEDM Collaboration
Axions and axion-like particles (ALPs) are popular dark matter candidates. Ultralight axion and ALP cold dark matter could manifest as a classical-like field, oscillating coherently on a galactic scale. Through their couplings to gluons, this field would induce an oscillation in the measured value of the electric dipole moments of neutrons and other particles. We analyse datasets from the Sussex-RAL-ILL nEDM experiment and the current nEDM experiment at the Paul Scherrer Institute (2015-2016) to obtain limits on a potential oscillation in the value of the EDM.
While many experiments probe the axion-photon coupling, we set the first laboratory limits on the axion-gluon coupling, improving upon the previous indirect cosmological limits by up to 3 orders of magnitude. Additionally, we improve upon laboratory constraints on the axion coupling to nucleons by up to a factor of 40.
Paper: Phys. Rev. X 7, 041034 (2017)- Search for Axionlike Dark Matter through Nuclear Spin Precession in Electric and Magnetic Fields