Dark matter searches — Axion-like dark matter via neutron and ¹⁹⁹Hg spin precession

Axion-like dark matter in the 10⁻²⁴ to 10⁻¹⁷ eV mass range would show up as an oscillating neutron electric dipole moment or an axion-wind spin-precession effect in stored ultracold neutrons and mercury-199 atoms.

Analysis of the ratio of neutron and ¹⁹⁹Hg spin-precession frequencies found no signal consistent with dark matter anywhere in that mass range.

Why it matched: similar wording

A submillimetre magnet levitated in a superconducting trap would detect the oscillating force from ultralight dark matter coupled to baryon-minus-lepton number.

With a force sensitivity of 0.2 fN/√Hz, the search found no evidence of a signal in the mass range 1.10360–1.10485 × 10⁻¹³ eV/c², giving a most stringent coupling limit of g(B−L) ≲ 2.98 × 10⁻²¹.

Why it matched: same research area · similar wording

A 46 kg liquid-argon time projection chamber with neutron and cosmic-ray vetoes would detect nuclear recoils from weakly interacting massive particles.

A 1,422 kg·day exposure with atmospheric argon gave a null result, setting a 90% CL upper limit on the WIMP–nucleon spin-independent cross-section of 6.1 × 10⁻⁴⁴ cm² at 100 GeV/c² — the most sensitive argon-target search to that date.

Why it matched: same research area