Joint Measurement of the ${}^{235}$U Antineutrino Spectrum by Prospect and Stereo

Abstract

The PROSPECT and STEREO collaborations present a combined measurement of the pure ${}^{235}$U antineutrino spectrum, without site specific corrections or detector-dependent effects. The spectral measurements of the two highest precision experiments at research reactors are found to be compatible with ${\chi }^2/\mathrm{ndf}=24.1/21$, allowing a joint unfolding of the prompt energy measurements into antineutrino energy. This ${\bar{\nu }}_e$ energy spectrum is provided to the community, and an excess of events relative to the Huber model is found in the 5-6 MeV region. When a Gaussian bump is fitted to the excess, the data-model ${\chi }^2$ value is improved, corresponding to a $2.4\sigma$ significance.

References in corpus (8)

• Improved Short-Baseline Neutrino Oscillation Search and Energy Spectrum Measurement with the PROSPECT Experiment at HFIR
• Reevaluating reactor antineutrino spectra with new measurements of the ratio between ${}^{235}$U and ${}^{239}$Pu $\beta$ spectra
• Reactor Fuel Fraction Information on the Antineutrino Anomaly
• Antineutrino Energy Spectrum Unfolding Based on the Daya Bay Measurement and Its Applications
• Precise Determination of the U-235 Reactor Antineutrino Cross Section per Fission
• First antineutrino energy spectrum from ${}^{235}$U fissions with the STEREO detector at ILL
• Prospects for Improved Understanding of Isotopic Reactor Antineutrino Fluxes
• Accurate Measurement of the Electron Antineutrino Yield of U-235 Fissions from the STEREO Experiment with 119 Days of Reactor-On Data

Cited by in corpus (8)

• Stereo neutrino spectrum of 235U fission rejects sterile neutrino hypothesis
• First measurement of high-energy reactor antineutrinos at Daya Bay
• Final Measurement of the U235 Antineutrino Energy Spectrum with the PROSPECT-I Detector at HFIR
• Reactor antineutrino flux and anomaly
• Final Search for Short-Baseline Neutrino Oscillations with the PROSPECT-I Detector at HFIR
• Long term remote reactor power and fuel composition monitoring using antineutrinos
• Measurement of cosmic muon-induced neutron background with ISMRAN detector in a non-reactor environment
• Calibration strategy of the PROSPECT-II detector with external and intrinsic sources