Revealing Fine Structure in the Antineutrino Spectra From a Nuclear Reactor

Abstract

We calculate the Inverse Beta Decay (IBD) antineutrino spectrum generated by nuclear reactors using the summation method to understand deviations from the smooth Huber-Mueller model due to the decay of individual fission products, showing that plotting the ratio of two adjacent spectra points can effectively reveal these deviations. We obtained that for binning energies of 0.1 MeV or lower, abrupt changes in the spectra due to the jagged nature of the individual antineutrino spectra could be observed for highly precise experiments. Surprisingly, our calculations also reveal a peak-like feature in the adjacent points ratio plot at 4.5 MeV even with a 0.25 MeV binning interval, which we find is present in the IBD Daya Bay spectrum published in 2016. We show that this 4.5 MeV feature is caused by the contributions of just four fission products, 95Y, 98,101N and 102Tc. This would be the first evidence of the decay of a few fission products in the IBD antineutrino spectrum from a nuclear reactor.

arXiv comment5 pages, 6 figures

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Cited by in corpus (16)

• Sterile Neutrinos
• Theory of Nuclear Fission
• Beta-decay studies for applied and basic nuclear physics
• Antineutrino Energy Spectrum Unfolding Based on the Daya Bay Measurement and Its Applications
• First antineutrino energy spectrum from ${}^{235}$U fissions with the STEREO detector at ILL
• Improving Fission-product Decay Data for Reactor Applications: Part I -- Decay Heat
• Measurement of Reactor Antineutrino Flux and Spectrum at RENO
• Reactor antineutrino flux and anomaly
• PROSPECT-II Physics Opportunities
• Mapping reactor neutrino spectra from TAO to JUNO
• Determination of Beta Decay Ground State Feeding of Nuclei of Importance for Reactor Applications
• JUNO Physics and Detector
• Studying the neutrino wave-packet effects at medium-baseline reactor neutrino oscillation experiments and the potential benefits of an extra detector
• Reactor Neutrino Spectral Distortions Play Little Role in Mass Hierarchy Experiments
• Potential impact of sub-structure on the resolution of neutrino mass hierarchy at medium-baseline reactor neutrino oscillation experiments
• First-principle event reconstruction by time-charge readouts for the Taishan Antineutrino Observatory