Constraints on axionlike dark matter with masses down to $10^{-23}$ eV/c$^2$

TL;DR

This study used a 6.7-year torsion-pendulum experiment with polarized electrons to set new constraints on ultralight axionlike dark matter across a wide mass range, improving existing limits.

Contribution

It provides the first experimental constraints on axionlike dark matter with masses as low as 10^{-23} eV/c^2, extending the search to extremely light particles.

Findings

95% confidence limit on decay constant F_a/C_e ≥ 10^{15} eV for most of the mass range

Established new bounds on ultralight axionlike dark matter

Extended the mass range of dark matter constraints down to 10^{-23} eV/c^2

Abstract

We analyzed an 6.7-year span of data from a rotating torsion-pendulum containing $\approx 10^{23}$ polarized electrons to search for the "wind" arising from ultralight, axionlike dark matter with masses between $10^{-23}$ and $10^{-18}$ eV/c$^2$. Over most of this range we obtain a 95\% confidence limit $F_{\rm a}/C_{\rm e} \geq 1 \times 10^{15}$ eV on the axionlike decay constant.