Stereo neutrino spectrum of 235U fission rejects sterile neutrino hypothesis

Abstract

Anomalies in past neutrino measurements have led to the discovery that these particles have non-zero mass and oscillate between their three flavors when they propagate. In the 2010's, similar anomalies observed in the antineutrino spectra emitted by nuclear reactors have triggered the hypothesis of the existence of a supplementary neutrino state that would be sterile i.e. not interacting via the weak interaction. The STEREO experiment was designed to study this scientific case that would potentially extend the Standard Model of Particle Physics. Here we present a complete study based on our full set of data with significantly improved sensitivity. Installed at the ILL (Institut Laue Langevin) research reactor, STEREO has accurately measured the antineutrino energy spectrum associated to the fission of 235U. This measurement confirms the anomalies whereas, thanks to the segmentation of the STEREO detector and its very short mean distance to the core (10~m), the same data reject the hypothesis of a light sterile neutrino. Such a direct measurement of the antineutrino energy spectrum suggests instead that biases in the nuclear experimental data used for the predictions are at the origin of the anomalies. Our result supports the neutrino content of the Standard Model and establishes a new reference for the 235U antineutrino energy spectrum. We anticipate that this result will allow to progress towards finer tests of the fundamental properties of neutrinos but also to benchmark models and nuclear data of interest for reactor physics and for observations of astrophysical or geo-neutrinos.

34 pages, 13 figures. Final version submitted to Nature

References in corpus (18)

• The Reactor Antineutrino Anomaly
• Sterile neutrino search at NEOS Experiment
• Results from the Baksan Experiment on Sterile Transitions (BEST)
• Updated Summation Model: An Improved Agreement with the Daya Bay Antineutrino Fluxes
• Improved Short-Baseline Neutrino Oscillation Search and Energy Spectrum Measurement with the PROSPECT Experiment at HFIR
• Experiment Neutrino-4 search for sterile neutrino and results of measurements
• Reevaluating reactor antineutrino spectra with new measurements of the ratio between ${}^{235}$U and ${}^{239}$Pu $\beta$ spectra
• Search for sterile neutrino oscillation using RENO and NEOS data
• Improved eV-scale Sterile-Neutrino Constraints from the Second KATRIN Measurement Campaign
• Exploring the hidden interior of the Earth with directional neutrino measurements
• Conversion of electron spectrum associated with fission into the antineutrino spectrum
• First antineutrino energy spectrum from ${}^{235}$U fissions with the STEREO detector at ILL
• Reactor antineutrino shoulder explained by energy scale nonlinearities?
• Accurate Measurement of the Electron Antineutrino Yield of U-235 Fissions from the STEREO Experiment with 119 Days of Reactor-On Data
• Production and Properties of the Liquid Scintillators used in the Stereo Reactor Neutrino Experiment
• Joint Measurement of the ${}^{235}$U Antineutrino Spectrum by Prospect and Stereo
• High Energy Physics Opportunities Using Reactor Antineutrinos
• Improved FIFRELIN de-excitation model for neutrino applications

Cited by in corpus (26)

• Direct observation of coherent elastic antineutrino-nucleus scattering
• Potential to identify neutrino mass ordering with reactor antineutrinos at JUNO
• Towards Resolving the Gallium Anomaly
• Reactor antineutrino flux and anomaly
• Reactor antineutrinos CE$\nu$NS on germanium: CONUS+ and TEXONO as a new gateway to SM and BSM physics
• Decoherence effects in reactor and Gallium neutrino oscillation experiments -- a QFT approach
• Improved Measurement of the Evolution of the Reactor Antineutrino Flux and Spectrum at Daya Bay
• Comprehensive Measurement of the Reactor Antineutrino Spectrum and Flux at Daya Bay
• Final Search for Short-Baseline Neutrino Oscillations with the PROSPECT-I Detector at HFIR
• Neutrino at different epochs of the Friedmann Universe
• Search for a light sterile neutrino with 7.5 years of IceCube DeepCore data
• Improved FIFRELIN de-excitation model for neutrino applications
• Neutrino phenomenology and keV dark matter in 2HDM with $A_4$ symmetry
• Measurement of cosmic muon-induced neutron background with ISMRAN detector in a non-reactor environment
• How to measure the reactor neutrino flux below the inverse beta decay threshold with CE$\nu$NS
• Restricting Sterile Neutrinos by Neutrinoless Double Beta Decay
• Analysis of reactor burnup simulation uncertainties for antineutrino spectrum prediction
• Invisible neutron decay and light BSM particles
• Low-Energy Neutrinos from Primordial Black Holes: A New Possibility for Observing Hawking Radiation
• First-principle event reconstruction by time-charge readouts for the Taishan Antineutrino Observatory
• Water-based Quantum Dots Liquid Scintillator for Particle Physics
• Sterile sector impacting the correlations and degeneracies among mixing parameters at the Deep Underground Neutrino Experiment
• Optimizing Sterile Neutrino Searches: Impact of Position Resolution in Short-Baseline Reactor Experiments
• Study of $\mathbf{\beta }$ Decay Shape Factors in First-Forbidden Transitions with $\mathbf{\Delta }{\mathbf{I}}^{\mathbf{\pi }}=0^{-}$ for Reactor Antineutrino Spectra Predictions
• νOscillation: a software package for computation and simulation of neutrino propagation and interaction
• Electron-antineutrino spectrum from precision measurements of ${}^{144}$Pr-decay