Protons may waltz off nuclear dance floor

In an atomic nucleus, protons and neutrons presumably dance around in twosomes, like couples at a grand ball. This hypothetical pairing, which is supported by experimental evidence, enables physicists to explain numerous traits of nuclei, including why some hold together more firmly than others.

For decades, experimenters have tried to find a nuclear decay in which a proton pair sashays right out of the nuclear ballroom, still entwined.