An experimental test of how frequently neutrinos interact with atomic nuclei has a best fit value of the Standard Model expectation and an uncertainty of less than ± 15%, which is impressive given how slight the interaction is, fit 10^22 trials yielding just 124 observed interactions.
The COHERENT collaboration reports the most precise measurement of the coherent elastic neutrino-nucleus scattering cross section to date. This measurement was performed with COHERENT's germanium detector array, Ge-Mini, at the Spallation Neutron Source at Oak Ridge National Laboratory.
A cumulative exposure of 4.68 × 10^22 protons on target yielded a total number of observed counts of 124 + 14 −12 and a flux-averaged cross section of 1.00 ± 0.10 (statistical) ± 0.10 (systematic) relative to the standard-model expectation of 5.9 × 10^−39 cm^2.
The well-understood energy and timing distributions of the neutrino source allow for independent measurements of muon- and electron-neutrino scattering rates. This information is used to improve constraints on non-standard neutrino interactions mediated by heavy particles.
M. Adhikari, et al., "Measurement of coherent elastic neutrino nucleus scattering on germanium by COHERENT" arXiv:2603.17951 (March 18, 2026).
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