Measurement of Coherent Elastic Neutrino-Nucleus Scattering from reactor antineutrinos

Understand

The 96.4 day exposure of a 3 kg ultra-low noise germanium detector to the high flux of antineutrinos from a power nuclear reactor is described.

• A very strong preference ($p<1.2\times10^{-3}$) for the presence of a coherent elastic neutrino-nucleus scattering (CE$\nu$NS) component in the data is found, when compared to a background-only model.
• No such effect is visible in 25 days of operation during reactor outages.
• The best-fit CE$\nu$NS signal is in good agreement with expectations based on a recent characterization of germanium response to sub-keV nuclear recoils.