Speaker
Description
The $\beta$-decay of $^8$He creates a significant background in antineutrino detectors based on the inverse $\beta$-decay mechanism due to the fact that it has $\beta$-delayed neutron final states and can be created by cosmic rays impinging on carbon. By providing excitation spectra and branching ratios for the $^8$He $\beta$-decay, this background can be quantified.
$^8$He is the most neutron-rich bound helium isotope and has the largest neutron-to-proton ratio of any bound nucleus. The diverse range of final states ($\gamma$+$^8$Li, n+$^7$Li, n+$\gamma$+$^7$Li and $\alpha$+n+t) for the decay provides a probe into the structure of $^8$Li excited states, a nucleus which is reachable by few-body quantum models.
Our experiment, performed at the ISOLDE Decay Station, is for the first time sensitive to every branch of the decay of $^8$He. In my talk I will present a holistic analysis of the decay of $^8$He, the challenges in extracting physics and the results of this effort.