High precision measurement of the $^6$He half-life

Abstract

The half-life of $^{6}$He has been measured using a low energy radioactive beam implanted in a YAP scintillator and recording decay events in a 4$\pi$ geometry. Events were time-stamped with a digital data acquisition system enabling a reliable control of dead-time effects and detector gain variations. The result, $T_{1/2} = (807.25 \pm 0.16_{\rm stat} \pm 0.11_{\rm sys}$)~ms, provides the most precise value obtained so far and is consistent with the only previous measurement having a precision smaller than 0.1%. This resolves the longstanding discrepancy previously observed between two sets of measurements.