Fig. 3: The improved limits for neutron coupling gann and proton coupling gapp from the 49 individual scans.
From: Constraining ultralight dark matter through an accelerated resonant search
The red spiky line indicates the 95%-confidence-level sensitivity, containing ~1.5 million test ALP frequencies. These frequencies are separated by Δf = 1/(2τa), the coherent time \({\tau }_{a} \sim 2\hslash /({m}_{a}{v}_{{{{{{{{\rm{vir}}}}}}}}}^{2})\), with ma and vvir the mass and virial velocity of the ALP. The complete dataset is available at ref. 75. The black line represents ±250 bins, averaging the red line to guide the reader's eye. Jiang et al.27, NASDUCK28, K-3He69, and ChangE-HSR70 are previous laboratory searches, while NS is the astrophysics limit from the neutron-star cooling76.
