English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

A considerable experimental effort is currently under way to test thepersistent hints for oscillations due to an eV-scale sterile neutrino in thedata of various reactor neutrino experiments. The assessment of the statisticalsignificance of these hints is usually based on Wilks' theorem, whereby theassumption is made that the log-likelihood is $\chi^2$-distributed. However, itis well known that the preconditions for the validity of Wilks' theorem are notfulfilled for neutrino oscillation experiments. In this work we derive a simpleasymptotic form of the actual distribution of the log-likelihood based onreinterpreting the problem as fitting white Gaussian noise. From this formalismwe show that, even in the absence of a sterile neutrino, the expectation valuefor the maximum likelihood estimate of the mixing angle remains non-zero withattendant large values of the log-likelihood. Our analytical results are thenconfirmed by numerical simulations of a toy reactor experiment. Finally, weapply this framework to the data of the Neutrino-4 experiment and show that thenull hypothesis of no-oscillation is rejected at the 2.6\,$\sigma$ level,compared to 3.2\,$\sigma$ obtained under the assumption that Wilks' theoremapplies.

Statistical interpretation of sterile neutrino oscillation searches at reactors