The debut of the antihydrogen beam

The standard model of particle physics suggests that matter and antimatter are equal and opposite in every way. Yet the observable Universe is made almost entirely of matter—an asymmetry that remains one of the greatest unsolved mysteries in physics.

In an advance that could make it possible to search for tiny differences between matter and antimatter and help to explain their imbalance in the cosmos, Yasunori Yamazaki and colleagues from the RIKEN Atomic Physics Laboratory, in collaboration with researchers from around the world, have now succeeded in creating a stable beam of antihydrogen atoms.