Precision Measurement of the 6He Half-Life and the Weak Axial Current in   Nuclei
  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. 
A. Knecht, R. Hong, D. W. Zumwalt, B. G. Delbridge, A. Garcia, P.   Mueller, H. E. Swanson, I. S. Towner, S. Utsuno, W. Will...
nucl-ex