Caught in the act,
Dark matter detector captures elusive nuclear decay in xenon

 

The picture shows the inside of the water shield surrounding the XENON1T
dark-matter detector
at the INFN Gran Sasso National Laboratory near L’Aquila in Italy. In this week’s issue of the Nature science journal, the XENON Collaboration reveals that the set-up has recorded a type of nuclear decay that is particularly hard to detect. The team has directly observed two-neutrino double electron capture in xenon-124, the half-life of which is roughly a trillion times the age of the Universe. The XENON1T detector contains 3.2 tonnes of ultra-pure xenon, and allowed the researchers to detect the X-rays emitted when xenon-124 decays into tellurium-124. They measured the half-life of this decay to be 1.8 × 10^22 years, which is in line with predictions. The team says that this detection is a useful step on the road to detecting neutrinoless double electron capture, which could provide a deeper understanding of the neutrino
.