Reactor Fuel Fraction Information on the Antineutrino Anomaly

Abstract

We analyzed the evolution data of the Daya Bay reactor neutrino experiment in terms of short-baseline active-sterile neutrino oscillations taking into account the theoretical uncertainties of the reactor antineutrino fluxes. We found that oscillations are disfavored at $2.6\sigma$ with respect to a suppression of the ${}^{235}\text{U}$ reactor antineutrino flux and at $2.5\sigma$ with respect to variations of the ${}^{235}\text{U}$ and ${}^{239}\text{Pu}$ fluxes. On the other hand, the analysis of the rates of the short-baseline reactor neutrino experiments favor active-sterile neutrino oscillations and disfavor the suppression of the ${}^{235}\text{U}$ flux at $3.1\sigma$ and variations of the ${}^{235}\text{U}$ and ${}^{239}\text{Pu}$ fluxes at $2.8\sigma$. We also found that both the Daya Bay evolution data and the global rate data are well-fitted with composite hypotheses including variations of the ${}^{235}\text{U}$ or ${}^{239}\text{Pu}$ fluxes in addition to active-sterile neutrino oscillations. A combined analysis of the Daya Bay evolution data and the global rate data shows a slight preference for oscillations with respect to variations of the ${}^{235}\text{U}$ and ${}^{239}\text{Pu}$ fluxes. However, the best fits of the combined data are given by the composite models, with a preference for the model with an enhancement of the ${}^{239}\text{Pu}$ flux and relatively large oscillations.

9 pages

References in corpus (3)

• The Reactor Antineutrino Anomaly
• Improved Measurement of the Reactor Antineutrino Flux and Spectrum at Daya Bay
• Experiment NEUTRINO-4 Search for Sterile Neutrino

Cited by in corpus (6)

• Sterile Neutrinos or Flux Uncertainties? - Status of the Reactor Anti-Neutrino Anomaly
• Diagnosing the Reactor Antineutrino Anomaly with Global Antineutrino Flux Data
• Prospects for Improved Understanding of Isotopic Reactor Antineutrino Fluxes
• A Low Mass Optical Grid for the PROSPECT Reactor Antineutrino Detector
• IceCube Sterile Neutrino Searches
• Sensitivity to sterile neutrino mixing using reactor antineutrinos