Logo
ScienceStack
Table of Contents
Fetching ...
Sign In

The COHERENT Experiment: 2026 Update

M. Adhikari, M. Ahn, D. Amaya Matamoros, P. S. Barbeau, V. Belov, I. Bernardi, C. Bock, A. Bolozdynya, R. Bouabid, J. Browning, B. Cabrera-Palmer, N. Cedarblade-Jones, S. Chen, A. I. Colón Rivera, V. da Silva, J. Daughhetee, Y. Efremenko, S. R. Elliott, A. Erlandson, L. Fabris, M. L. Fischer, S. Foster, A. Galindo-Uribarri, E. Granados Vazquez, M. P. Green, B. Hackett, J. Hakenmüller, M. Harada, M. R. Heath, S. Hedges, Y. Hino, H. Huang, W. Huang, H. Jeong, B. A. Johnson, T. Johnson, A. Khromov, D. Kim, L. Kong, A. Konovalov, Y. Koshio, E. Kozlova, A. Kumpan, O. Kyzylova, Y. Lee, S. M. Lee, G. Li, L. Li, Z. Li, J. M. Link, J. Liu, Q. Liu, X. Lu, M. Luxnat, D. M. Markoff, J. Mattingly, H. McLaurin, K. McMichael, N. Meredith, Y. Nakajima, F. Nakanishi, J. Newby, B. Nolan, J. O'Reilly, A. Orvedahl, D. S. Parno, D. Pérez-Loureiro, D. Pershey, C. G. Prior, J. Queen, R. Rapp, H. Ray, O. Razuvaeva, D. Reyna, D. Rudik, J. Runge, D. J. Salvat, J. Sander, K. Scholberg, H. Sekiya, J. Seligman, A. Shakirov, G. Simakov, J. Skweres, W. M. Snow, V. Sosnovtsev, Q. Stefan, M. Stringer, C. Su, T. Subedi, B. Suh, B. Sur, R. Tayloe, Y. -T. Tsai, J. Vaccaro, E. E. van Nieuwenhuizen, C. J. Virtue, G. Visser, K. Walkup, E. M. Ward, R. Wendell, T. Wongjirad, C. Yang, Y. Yang, J. Yoo, C. -H. Yu, Y. Yu, A. Zaalishvili, J. Zettlemoyer, Y. Zheng

TL;DR

The COHERENT 2026 update outlines a programat SNS/ORNL to perform high-statistics CEvNS measurements across multiple targets (CsI, Ar, Ge, NaI, Ne) and to pursue inelastic neutrino-nucleus cross sections relevant to supernova physics. By exploiting the pulsed, well-characterized stopped-pion flux and a diversified detector portfolio, the experiment aims for percent-level precision through lower thresholds, larger masses, and reduced systematics, including flux via D$_2$O measurements and form-factor studies. The paper highlights key physics goals: NSI constraints, light mediators, weak mixing angle at low $Q^2$, sterile neutrinos, accelerator-produced dark matter, and neutron-form-factor measurements that connect to neutron-star physics, as well as the impact on interpreting neutrino backgrounds in dark-matter searches. In addition to CEvNS, COHERENT will illuminate tens-of-MeV inelastic channels on several nuclei, improving our understanding of core-collapse supernova neutrinos and informing large-scale detectors like DUNE and Hyper-K. These advances position COHERENT to deliver precise SM tests and robust BSM constraints with data from both SNS and reactor-based CEvNS efforts. $E_ u$-dependent cross sections, recoil spectra, and timing structure provided by the SNS enable a comprehensive exploration of low-energy neutrino interactions and their astrophysical implications.

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.

The COHERENT Experiment: 2026 Update

TL;DR

The COHERENT 2026 update outlines a programat SNS/ORNL to perform high-statistics CEvNS measurements across multiple targets (CsI, Ar, Ge, NaI, Ne) and to pursue inelastic neutrino-nucleus cross sections relevant to supernova physics. By exploiting the pulsed, well-characterized stopped-pion flux and a diversified detector portfolio, the experiment aims for percent-level precision through lower thresholds, larger masses, and reduced systematics, including flux via DO measurements and form-factor studies. The paper highlights key physics goals: NSI constraints, light mediators, weak mixing angle at low , sterile neutrinos, accelerator-produced dark matter, and neutron-form-factor measurements that connect to neutron-star physics, as well as the impact on interpreting neutrino backgrounds in dark-matter searches. In addition to CEvNS, COHERENT will illuminate tens-of-MeV inelastic channels on several nuclei, improving our understanding of core-collapse supernova neutrinos and informing large-scale detectors like DUNE and Hyper-K. These advances position COHERENT to deliver precise SM tests and robust BSM constraints with data from both SNS and reactor-based CEvNS efforts. -dependent cross sections, recoil spectra, and timing structure provided by the SNS enable a comprehensive exploration of low-energy neutrino interactions and their astrophysical implications.

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 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.
Paper Structure (7 sections, 4 figures, 2 tables)

This paper contains 7 sections, 4 figures, 2 tables.

Table of Contents

  1. Introduction
  2. Scientific context
  3. The ORNL SNS Neutrino Source
  4. COHERENT in Neutrino Alley
  5. Physics Reach
  6. Conclusion
  7. Acknowledgements

Figures (4)

  • Figure 1: Left: SNS-flux-averaged CEvNS cross section as function of the neutron number of the target nucleus including the impact of the nuclear form factor (FF). The COHERENT CEvNS detections at SNS are marked. Right: flux-averaged cross section for various neutrino sources (SNS, reactor, solar), including the most precise current detections and upper limits for each neutrino source and target combination.
  • Figure 2: Approximate figure-of-merit plot for spallation sources of neutrinos, including past, current and future sources. The $x$ axis is neutrino flux, and the $y$-axis represents the inverse square root of the duty cycle. "Iso-merit" lines are shown as diagonal lines representing constant signal over square root of steady-state background; further to the upper right means better. Further details in Ref. Asaadi:2022ojmks.
  • Figure 3: Current state of Neutrino Alley in the SNS basement.
  • Figure 4: Left: using CEvNS to probe the LMA dark solution to the solar neutrino problem with CryoCsI with 10 kg mass and 30 kg-yr exposure. Right: projected sensitivities for exclusion limits on sub-GeV dark matter. Figures from Ref. COHERENT:2023sol.