Statistical Significance of the Gallium Anomaly

TL;DR

This paper evaluates the statistical significance of the Gallium anomaly in neutrino detection experiments, considering cross-section uncertainties, and finds evidence suggestive of short-baseline electron neutrino disappearance.

Contribution

It provides a detailed statistical analysis of the Gallium anomaly, incorporating detection uncertainties, and assesses the evidence for neutrino oscillations.

Findings

Anomaly significance is about 3.0 sigma.

Data favors short-baseline electron neutrino disappearance at 2.7 sigma.

Supports the hypothesis of neutrino oscillations in the Gallium experiments.

Abstract

We calculate the statistical significance of the anomalous deficit of electron neutrinos measured in the radioactive source experiments of the GALLEX and SAGE solar neutrino detectors taking into account the uncertainty of the detection cross section. We found that the statistical significance of the anomaly is about 3.0 sigma. A fit of the data in terms of neutrino oscillations favors at about 2.7 sigma short-baseline electron neutrino disappearance with respect to the null hypothesis of no oscillations.