New Limit on Axion-Like Dark Matter using Cold Neutrons

Abstract

We report on a search for dark matter axion-like 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 $\hat{I}¼$Hz to 1 kHz, and no significant oscillating signal has been found. The usage of present dark-matter models allows to constrain the coupling of ALPs to gluons in the mass range from $10^{-19}$ to $4\times 10^{-12}$ eV. The best limit of $C_G$/$f_a{m}_a=2.7\times 10^{13}$ GeV${}^{-2}$ (95\% C.L.) is reached in the mass range from $2\times 10^{-17}$ to $2\times 10^{-14}$ eV.

accepted version