Physical Review C - Nuclear Physics
Background: The β decays of 3H and 6He can play an important role in testing nuclear wave-function calculations and fixing low-energy constants in effective-field theory approaches. However, there exists a large discrepancy between previous measurements of the 6He half-life. Purpose: Our measurement aims at resolving this long-standing discrepancy in the 6He half-life and providing a reliable ft value and Gamow-Teller matrix element for comparison with theoretical ab initio calculations. Method: We measured the 6He half-life by counting the β-decay electrons with two scintillator detectors operating in coincidence. Results: The measured 6He half-life is 806.89±0.11 stat-0.19+0.23syst ms corresponding to a relative precision of 3×10-4. Calculating the statistical rate function we determined the ft value to be 803.04-0.23+0.26 s. Conclusions: Our result resolves the previous discrepancy by providing a higher-precision result with careful analysis of potential systematic uncertainties. The result provides a reliable basis for future precision comparisons with ab initio calculations. © 2012 American Physical Society.
© 2012 American Physical Society
Knecht, A.; Hong, R.; Zumwalt, D. W.; Delbridge, B. G.; García, A.; Müller, P.; Swanson, H. E.; Towner, I. S.; Utsuno, S.; Williams, William; and Wrede, C., "Precision Measurement of the 6He Half-Life and the Weak Axial Current in Nuclei" (2012). Physics: Faculty Publications, Smith College, Northampton, MA.