Precision Measurement of the 6He Half-Life and the Weak Axial Current in Nuclei

TL;DR

This paper reports a highly precise measurement of the 6He half-life, resolving previous discrepancies, and compares the results with theoretical calculations to test nuclear models and effective field theories.

Contribution

An improved measurement of the 6He half-life with 3x10^(-4) precision, resolving prior inconsistencies and enabling better testing of nuclear theories.

Findings

Half-life of 6He measured as 806.89 ms with high precision.

The ft-value calculated as approximately 803 seconds.

Gamow-Teller matrix element agrees with ab-initio calculations.

Abstract

Studies of 6He beta decay along with tritium can play an important role in testing ab-initio nuclear wave-function calculations and may allow for fixing low-energy constants in effective field theories. Here, we present an improved determination of the 6He half-life to a relative precision of 3x10^(-4). Our value of 806.89 \pm 0.11(stat)^{+0.23}_{-0.19}(syst) ms resolves a major discrepancy between previous measurements. Calculating the statistical rate function we determined the ft-value to be 803.04 ^{+0.26}_{-0.23} s. The extracted Gamow-Teller matrix element agrees within a few percent with ab-initio calculations.