Search for Axionlike Dark Matter through Nuclear Spin Precession in Electric and Magnetic Fields

We report on a search for ultralow-mass axionlike dark matter by analyzing the ratio of the spinprecession frequencies of stored ultracold neutrons and 199 Hg 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 10 -24 m a 10 -17 eV. 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.