2024/12/18 by Colaresi, J., Collar, J. I., Hossbach, T. W. +2
paper · doi:10.6082/uchicago.14269
The 96.4 day exposure of a 3 kg ultralow noise germanium detector to the high flux of antineutrinos from a power nuclear reactor is described. A very strong preference (p <1.2 ×10−3) for the presence of a coherent elastic neutrino-nucleus scattering (CE𝜈NS) 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 CE𝜈NS signal is in good agreement with expectations based on a recent characterization of germanium response to sub-keV nuclear recoils. Deviations of order 60% from the standard model CE𝜈NS prediction can be excluded using present data. Standing uncertainties in models of germanium quenching factor, neutrino energy spectrum, and background are examined.