The excited states of an atom’s nucleus are fingerprints of its structure. The energies and patterns of excited states tell us about the shape of the nucleus and how individual protons and neutrons interact with each other. Models for nuclei “near stability,” or those we find around us in nature, provide a very good description of these excited states. However, a predictive model that works with weakly bound nuclei, at the limits of nuclear stability, remains elusive.
Measurements of the most exotic systems that scientists can create in the laboratory are key to improving models and getting to a predictive description. Now, the first glimpse into the structure of the very neutron-rich magnesium-40 (12 protons, 28 neutrons) provides a new and critical data point for weakly bound nuclei very near this stability limit. Read more.