Final Search for Short-Baseline Neutrino Oscillations with the PROSPECT-I Detector at HFIR

Abstract

The PROSPECT experiment is designed to perform precise searches for antineutrino disappearance at short distances (7 - 9~m) from compact nuclear reactor cores. This Letter reports results from a new neutrino oscillation analysis performed using the complete data sample from the PROSPECT-I detector operated at the High Flux Isotope Reactor in 2018. The analysis uses a multi-period selection of inverse beta decay neutrino interactions with reduced backgrounds and enhanced statistical power to set limits on electron-flavor disappearance caused by mixing with sterile neutrinos with 0.2 - 20 eV${}^2$ mass splittings. Inverse beta decay positron energy spectra from six different reactor-detector distance ranges are found to be statistically consistent with one another, as would be expected in the absence of sterile neutrino oscillations. The data excludes at 95% confidence level the existence of sterile neutrinos in regions above 3~eV${}^2$ previously unexplored by terrestrial experiments, including all space below 10~eV${}^2$ suggested by the recently strengthened Gallium Anomaly. The best-fit point of the Neutrino-4 reactor experiment's claimed observation of short-baseline oscillation is ruled out at more than five standard deviations.

6 pages, 4 figures

References in corpus (19)

• Observation of electron-antineutrino disappearance at Daya Bay
• The Reactor Antineutrino Anomaly
• Statistical Significance of the Gallium Anomaly
• Sterile neutrino search at NEOS Experiment
• Updated Summation Model: An Improved Agreement with the Daya Bay Antineutrino Fluxes
• A Search for Electron Neutrino Transitions to Sterile States in the BEST Experiment
• Reactor antineutrino anomaly in light of recent flux model refinements
• Improved Search for a Light Sterile Neutrino with the Full Configuration of the Daya Bay Experiment
• Searching for eV-scale sterile neutrinos with eight years of atmospheric neutrinos at the IceCube neutrino telescope
• Stereo neutrino spectrum of 235U fission rejects sterile neutrino hypothesis
• Analysis of the Daya Bay Reactor Antineutrino Flux Changes with Fuel Burnup
• First constraints on light sterile neutrino oscillations from combined appearance and disappearance searches with the MicroBooNE detector
• Improved eV-scale Sterile-Neutrino Constraints from the Second KATRIN Measurement Campaign
• Antineutrino Energy Spectrum Unfolding Based on the Daya Bay Measurement and Its Applications
• Lithium-loaded Liquid Scintillator Production for the PROSPECT experiment
• Final Measurement of the U235 Antineutrino Energy Spectrum with the PROSPECT-I Detector at HFIR
• Joint Measurement of the ${}^{235}$U Antineutrino Spectrum by Prospect and Stereo
• PROSPECT-II Physics Opportunities
• A Low Mass Optical Grid for the PROSPECT Reactor Antineutrino Detector

Cited by in corpus (2)

• Search for Light Sterile Neutrinos With Two Neutrino Beams at MicroBooNE
• Freeze-in and Freeze-out in a Right-Handed Neutrino Extended MSSM with a Seesaw Mechanism