Reassessing the gallium anomaly using self-consistent electron wave functions

TL;DR

This paper reevaluates the gallium anomaly by calculating neutrino capture cross sections with self-consistent electron wave functions, providing updated insights into its significance and possible sterile neutrino explanations.

Contribution

It introduces a novel, self-consistent calculation method for electron wave functions in neutrino capture, challenging previous approximations and refining the anomaly's interpretation.

Findings

Revised neutrino capture cross sections reduce the anomaly's significance.

Updated analysis suggests the anomaly may be less indicative of sterile neutrinos.

Provides the most current assessment of the gallium anomaly's status.

Abstract

The gallium anomaly, a persistent discrepancy exceeding $4\sigma$ in the $^{71}$Ga neutrino capture rates from $^{51}$Cr and $^{37}$Ar radioactive sources by the GALLEX, SAGE, and recently BEST experiments, has challenged particle physics and nuclear theory for over three decades. We present a new calculation of the neutrino capture cross section, abandoning the conventional leading-order approximation for electronic wave functions by numerically solving the Dirac-Coulomb equation for both bound and continuum electron states. Finally, we reevaluate the gallium anomaly, updating its global significance and presenting the most up-to-date status of its interpretation in terms of sterile neutrinos.