Fig. 6: Exclusion plot for the electron coupling (mean limits).

Other laboratory (solid lines) and astrophysical (dashed lines) constraints are shown for reference and extracted from ref. ⁵⁶: Electron g−2⁶³, Torsion pendulum^64,65, K-³He³⁰, XENONnT (Solar Axions)⁶⁶, Solar neutrinos⁶⁷, and red giant branch⁶⁸.