Physicists trap a single antimatter particle for months to understand how matter began to dominate the universe after big bang

Northwestern University scientists have trapped a single positron, the antimatter counterpart of an electron, for months while cooling it to nearly absolute zero and controlling its quantum states. The breakthrough could enable an unprecedentedly precise comparison of the magnetic properties of matter and antimatter, potentially revealing gaps in the Standard Model of particle physics and offering clues to why the universe contains far more matter than antimatter.