Nuclear physicists at the University of Tennessee have solved a 20-year mystery about how gold forms in the universe. Their research reveals how unstable atomic nuclei break apart during the rapid neutron capture process, a key step in creating heavy elements like gold and platinum. The findings could significantly improve models of stellar events that forge these precious metals.

Working at CERN's ISOLDE facility, the team made three groundbreaking discoveries about rare nuclear transformations. Using advanced neutron detectors and laser separation techniques, they measured neutron energies from beta-delayed two-neutron emission for the first time. This process occurs only in exotic, unstable nuclei that exist briefly during stellar explosions and collisions.

The researchers also observed a long-predicted neutron state in tin-133 that had eluded detection for two decades. This discovery challenges existing nuclear models and suggests current theories are incomplete. Their third finding revealed unexpected patterns in how nuclear states populate during decay, indicating that models may fail for nuclei far from stability. These insights will help scientists better understand element formation in extreme cosmic environments.