The COHERENT Experiment: 2026 Update

TL;DR

The COHERENT experiment aims to precisely measure neutrino-nucleus interactions at the SNS, improving understanding of the standard model and probing new physics through high-statistics CEvNS detection with multiple nuclear targets.

Contribution

This paper updates on the COHERENT experiment's progress, detailing plans for high-precision CEvNS measurements, detector scaling, and new target nuclei to test theoretical predictions and explore neutrino interactions.

Findings

Successful CEvNS measurements with various detectors

Plans for high-statistics, low-threshold detection

Measurement of previously unmeasured neutrino-nucleus cross sections

Abstract

The COHERENT experiment measures neutrino-induced recoils from coherent elastic neutrino-nucleus scattering (CEvNS) with multiple nuclear targets at the Spallation Neutron Source (SNS) at the Oak Ridge National Laboratory (ORNL), USA. Several successful CEvNS measurements have been achieved in recent years with tens-of-kg detector masses, with a CsI scintillating crystal, a liquid argon single-phase detector, and high-purity germanium spectrometers. For the next phase, COHERENT aims at high-statistics detection of CEvNS events for precision tests of the standard model of particle physics, and to probe new physics beyond-the-standard model. Percent-level precision can be achieved by lowering thresholds, reducing backgrounds, and by scaling up the detector masses. It goes hand in hand with benchmarking the neutrino flux from the SNS. Further detectors will measure CEvNS in additional nuclei, including lighter target nuclei such as sodium and neon, to continue to test the expected neutron-number-squared dependence of the cross section. COHERENT can furthermore study charged-current and neutral-current inelastic neutrino-nucleus cross sections on various nuclei at neutrino energies below $\sim$50 MeV. Many of these cross sections have never been measured before, but are critical input for the interpretation of core-collapse supernova detection in large-scale neutrino experiments such as DUNE, Super-K, Hyper-K, and HALO.