New Limit on Axionlike Dark Matter Using Cold Neutrons

Abstract

We report on a search for dark matter axionlike particles (ALPs) using a Ramsey-type apparatus for cold neutrons. A hypothetical ALP-gluon coupling would manifest in a neutron electric dipole moment signal oscillating in time. Twenty-four hours of data have been analyzed in a frequency range from 23 μHz to 1 kHz, and no significant oscillating signal has been found. The usage of present dark-matter models allows one to constrain the coupling of ALPs to gluons in the mass range from 10-19 to 4×10-12 eV. The best limit of CG/fama=2.7×1013 GeV-2 (95% C.L.) is reached in the mass range from 2×10-17 to 2×10-14 eV.