Speaker
Description
This contribution reports the final results of the IS541 experiment that searched for beta-delayed proton emission from 11Be through detection of the final state nucleus 10Be with accelerator mass spectrometry, coupled to a determination of the 11Be intensity via gamma decays. A first experiment (published 2014 [1]) reported an observation of the decay branch. In a follow-up experiment twelve samples were collected at ISOLDE at different separator settings, allowing tests of different sources of contamination to be made. The observed amounts of 10Be per collected 11Be rule out several contamination sources, but do not agree internally and seem to be inconsistent with a recent experiment from TRIUMF [2]. Possible explanations for the disagreement will be discussed.
[1] K. Riisager et al., Phys.Lett. B732 (2014) 305
[2] Y. Ayyad et al., Phys.Rev.Lett. 123, 082501 (2019)
