Measurement of coherent elastic neutrino nucleus scattering on germanium by COHERENT

Abstract

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 $4.68\times 10^{22}$ protons on target yielded a total number of observed counts of $124_{-12}^{+14}$ and a flux-averaged cross section of $1.00\pm 0.10(\mathrm{statistical})\pm 0.10(\mathrm{systematic})$ relative to the standard-model expectation of $5.9\times 10^{-39}{\mathrm{cm}}^2$. 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.