CERN has a long history of antimatter research; the first antihydrogen atoms were produced at CERN in 1995. However, the fleeting existence of antiatoms meant that they could not be used for further studies: each one existed for only about 40 billionths of a second and travelled at the speed of light before annihilating with ordinary matter.
In November the ALPHA collaboration announced that it had successfully trapped 38 antihydrogen atoms for around 170ms — long enough to potentially study their properties. Weeks later the ASACUSA group announced that they had made a major breakthrough towards creating a beam of antihydrogen suitable for spectroscopic studies.
These two techniques open the door to future studies of antimatter. The procedures used to form antihydrogen build on techniques developed by a third antihydrogen experiment at CERN, ATRAP, which pioneered trapping techniques in the 1990s, and is also working on trapping antihydrogen.
Antimatter research was not the only appearance CERN made in Physics World’s top 10: the first LHC collisions also made the list, coming in at number 10.