Direct observation of coherent elastic antineutrino-nucleus scattering

Abstract

Neutrinos are elementary particles that interact only very weakly with matter. Neutrino experiments are, therefore, usually big, with masses in the multi-tonne range. The thresholdless interaction of coherent elastic scattering of neutrinos on atomic nuclei leads to greatly enhanced interaction rates, which allows for much smaller detectors. The study of this process gives insights into physics beyond the Standard Model of particle physics. The CONUS+ experiment was designed to first detect elastic neutrino-nucleus scattering in the fully coherent regime with low-energy neutrinos produced in nuclear reactors. For this purpose, semi-conductor detectors based on high-purity germanium crystals with extremely low-energy thresholds were developed. Here we report the first observation of a neutrino signal with a statistical significance of 3.7 sigma from the CONUS+ experiment, operated at the nuclear power plant in Leibstadt, Switzerland. In 119 days of reactor operation (395$\pm$106) neutrinos were measured compared with a predicted number from calculations assuming Standard Model physics of (347$\pm$59) events. With increased precision, there is potential for fundamental discoveries in the future. The CONUS+ results in combination with other measurements of this interaction channel might therefore mark a starting point for a new era in neutrino physics.

27 pages, 10 figures, 4 tables

References in corpus (16)

• Observation of Coherent Elastic Neutrino-Nucleus Scattering
• \textsc{MaGe} - a {\sc Geant4}-based Monte Carlo Application Framework for Low-background Germanium Experiments
• Updated Summation Model: An Improved Agreement with the Daya Bay Antineutrino Fluxes
• Measurement of the Coherent Elastic Neutrino-Nucleus Scattering Cross Section on CsI by COHERENT
• Constraints on elastic neutrino nucleus scattering in the fully coherent regime from the CONUS experiment
• Measurement of Coherent Elastic Neutrino-Nucleus Scattering from reactor antineutrinos
• Stereo neutrino spectrum of 235U fission rejects sterile neutrino hypothesis
• Direct measurement of the ionization quenching factor of nuclear recoils in germanium in the keV energy range
• Search for coherent elastic neutrino-nucleus scattering at a nuclear reactor with CONNIE 2019 data
• First results of the nuGeN experiment on coherent elastic neutrino-nucleus scattering
• First measurement of high-energy reactor antineutrinos at Daya Bay
• Final CONUS results on coherent elastic neutrino-nucleus scattering at the Brokdorf reactor
• Full background decomposition of the CONUS experiment
• On the impact of the Migdal effect in reactor CE$\nu$NS experiments
• Pulse shape discrimination for the CONUS experiment in the keV and sub-keV regime
• Light vector bosons and the weak mixing angle in the light of future germanium-based reactor CE$\nu$NS experiments

Cited by in corpus (18)

• Constraints on New Physics with Light Mediators and Generalized Neutrino Interactions via Coherent Elastic Neutrino Nucleus Scattering
• Standard Model Tested with Neutrinos
• Nucleon Short-Range Correlations and High-Momentum Dynamics: Implications on the Equation of State of Dense Matter
• Toward precision physics tests with future COHERENT detectors
• Testing the dark side of neutrino oscillations with the solar neutrino fog at Dark Matter experiments
• Muon-Decay Parameters from COHERENT
• New light mediators and the neutrino fog: Implications from XENONnT nuclear recoil data
• Particle background characterization and prediction for the NUCLEUS reactor CE$\nu$NS experiment
• When backgrounds become signals: neutrino interactions in xenon-based dark matter detectors
• Enhanced Athermal Phonon Responsivity in a Kinetic Inductance Detector with Integrated Phonon Collectors
• Reducing Hadronic Uncertainty in Low-Energy Neutral-Current Processes
• Unified framework for precise background modeling to enhance rare event detection at the Kuo-Sheng nuclear reactor laboratory
• Constraints on active-sterile neutrino transition magnetic moments from low-energy electronic recoils at direct detection experiments
• Prospect of the NUCLEUS Experiment at Chooz for Coherent Elastic Neutrino-Nucleus Scattering and New Physics Searches
• Probing neutrino-night-quark effective scalar interactions from neutrino masses
• Neutrino nonstandard interactions: Confronting COHERENT and LHC data
• Testing lepton non-unitarity with the next generation of Germanium-based CE$\nu$NS reactor experiments
• Probing the Solar ${}^8$B Neutrino Fog with XENONnT