The COHERENT collaboration: initial results and present status

Sam Hedges

Using neutrinos produced at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL), the COHERENT collaboration recently made the first observation of coherent elastic neutrino-nucleus scattering (CE𝜈NS) in a 14.6 kg CsI[Na] detector. CE𝜈NS is a standard model neutral-current process in which a neutrino interacts coherently with the nucleons inside a nucleus. The coherence of the recoiling nucleons leads to a large cross section proportional to N2, the number of neutrons in the nucleus squared. While CE𝜈NS was first predicted in 1974, it eluded detection for more than forty years due to the low energy nuclear recoils involved. CE𝜈NS is useful for understanding supernova dynamics, characterizing backgrounds for dark matter experiments, searching for non- standard interactions, and has potential applications for monitoring nuclear reactors. To test the N2 scaling of the cross section and further study the physics of this interaction, COHERENT is deploying a variety of detector targets and technologies to the SNS, including a single-phase liquid argon detector, a p-type point contact germanium detector, a CsI[Na] scintillating detector, and a large segmented NaI[Tl] scintillating detector. Additionally, COHERENT is studying inelastic neutrino cross sections on a variety of targets. Results from COHERENT's first detection of CE𝜈NS in CsI[Na] will be presented, as well as updates on the current experimental status and future plans.