A better view of the strong force:
An IRIS experiment discovered that using rare isotopes to scatter protons can reveal subtle, new characteristics of the nuclear strong force which binds protons and neutrons, the building blocks of all matter. The strong force appeared well understood for explaining simple nuclei, such as hydrogen isotopes, but its extension to complex, many body systems has exposed important gaps. Theorists have proposed new models, but many strong force characteristics in these models can only be constrained with experiments. As reported in Physical Review Letters (2017), using the rare isotope carbon-10 (10C), IRIS's researchers showed that the intensity distribution of scattered protons by rare isotope is highly sensitive to different theoretical models of the strong force, providing a key new way to constrain them.