Scientists crack a 20-year nuclear mystery behind the creation of gold (sciencedaily.com)

A team of nuclear physicists used experiments at CERN’s ISOLDE facility to clarify key steps in the r-process, the rapid neutron-capture pathway that forges heavy elements like gold. They report the first measurements of neutron energies tied to beta-delayed emission of two neutrons, the observation of a long-predicted single-particle neutron state in tin-133, and evidence that the population of the relevant nuclear state doesn’t follow expected statistical patterns. The findings are intended to improve models of the extreme stellar events that produce heavy elements and refine understanding of exotic, short-lived nuclei.