Migdal effect directly observed in neutron–nucleus collisions at 5σ
Researchers report the first direct observation of the Migdal effect in neutron–nucleus scattering, achieving 5σ significance from six Migdal events in roughly 8.17×10^5 recorded neutron-induced tracks with a specialized gaseous pixel detector. The measured Migdal-to-nuclear-recoil cross-section ratio is (4.9_{-1.9}^{+2.6})×10^-5 for 5–10 keV electron recoils and NR >35 keVee, in agreement with a theoretical prediction of 3.9×10^-5 within uncertainties. This direct validation strengthens the Migdal effect’s role in enhancing sensitivity for light dark matter searches and provides crucial groundwork for detector design and background control in such experiments.