Direct observation of the Migdal effect induced by neutron bombardment

Abstract The search for dark matter focuses now on hypothetical light particles with masses ranging from MeV to GeV (refs. 1–12 ). These particles would leave very faint signals experimentally. A potential avenue for enhancing experimental sensitivity to light matter relies on the Migdal effect 13–15 , which involves the detectable ejection of electrons following the instantaneous accelerations of atoms colliding with neutral dark matter. However, although the Migdal effect could be equally generated in controlled experiments with neutral projectiles, a direct experimental observation of this effect is missing, casting doubt on the reliability of detection experiments relying on this effect. Here we report the…