Reevaluating reactor antineutrino anomalies with updated flux predictions

Abstract

Hints for the existence of a sterile neutrino at nuclear reactors are reexamined using two updated predictions for the fluxes of antineutrinos produced in fissions. These new predictions diverge in their preference for the rate deficit anomaly, relative to previous analyses, but the anomaly in the ratios of measured antineutrino spectra persists. We comment on upcoming experiments and their ability to probe the preferred region of the sterile-neutrino parameter space in the electron neutrino disappearance channel. arXiv:1909.09267v1 [hep-ph]

A new analysis of the MiniBooNE low-energy excess

“…One can see that the changes are similar to those for MiniBooNE alone (shown in figure 2): there is a clear shift of the allowed regions towards small mixing. In particular, the allowed region with small mixing around ∆m 2 41 ≈ 2 eV 2 may be compatible with indications of short-baselineν e disappearance due to active-sterile neutrino mixing found in reactor experiments [4,[27][28][29][30][31][32].…”

Current and future neutrino oscillation constraints on leptonic unitarity

“…The averaged-out regime of these searches, which is required to perform this mapping, depends on flux and cross section uncertainties to be well understood in a disappearance search. The overall flux of these searches is notoriously difficult to constrain [90][91][92][93], so these experiments do not place robust, strong limits in the high-∆m 2 Table 2. Sterile neutrino searches included in our analysis, and the associated 90% CL limit on the effective mixing angle from the given experimental search.…”

KATRIN bound on 3+1 active-sterile neutrino mixing and the reactor antineutrino anomaly

“…[28] of reactor antineutrino data compared with the Huber-Muller prediction [10,11] (see also ref. [29]). One can see that the combined constraints of tritium-decay experiments can exclude the large-∆m 2 41 part of the RAA 99% allowed region, but it is still too weak to affect the 90% allowed region around the best-fit point.…”

“…[41,42] using the 2018 [33] DANSS data and in ref. [29] using both the 2018 and the 2019 [34] DANSS data. Here, as explained above, we use the 2019 DANSS data, that lead to a diminished indication in favor of shortbaseline oscillations with respect to the 2018 DANSS data.…”