New Measurements of $^{71}$Ge Decay: Impact on the Gallium Anomaly

TL;DR

This study provides precise measurements of $^{71}$Ge decay, confirming the accepted half-life and constraining alternative decay hypotheses, thereby reinforcing the significance of the gallium anomaly in neutrino experiments.

Contribution

The paper presents high-precision measurements of $^{71}$Ge decay that confirm the standard half-life and rule out certain decay channels, impacting interpretations of the gallium anomaly.

Findings

Measured $^{71}$Ge half-life consistent with 11.43 days

Constraints on $^{71}$Ge decay to excited levels of $^{71}$Ga

Gallium anomaly remains statistically significant

Abstract

A dedicated high-statistics measurement of the $^{71}$Ge half-life is found to be in accurate agreement with an accepted value of 11.43$\pm$0.03 d, eliminating a recently proposed route to bypass the "gallium anomaly" affecting several neutrino experiments. Our data also severely constrain the possibility of $^{71}$Ge decay to low-energy excited levels of the $^{71}$Ga daughter nucleus as a solution to this puzzle. Additional unpublished measurements of this decay are discussed. Following the incorporation of this new information, the gallium anomaly survives with high statistical significance.