antimatterrelated

Antimatter refers to particles that have the same mass as their matter counterparts but opposite electric charge and other quantum numbers. When a particle meets its corresponding antiparticle, they annihilate each other, typically producing photons and, in some cases, other particle-antiparticle pairs. The best known example is the positron, the antiparticle of the electron. Antiprotons, antineutrons, and other antiparticles have been observed in laboratories and in cosmic rays.

Antimatter can be produced in high-energy collisions, nuclear reactions, and certain radioactive decays. Modern accelerators routinely create short-lived antiparticles, and antimatter is stored in traps using strong magnetic or electric fields to prevent contact with ordinary matter. Because annihilation with even small amounts of material releases energy, containment is technologically demanding and costly.

Antimatter has practical uses and is central to fundamental physics. Positrons are used in medical imaging, such as PET scanners. Research into antihydrogen and other antiatoms tests fundamental symmetries, including CPT invariance. Antiprotons and other antiparticles are used in particle physics experiments to study interactions at high energy and to probe the internal structure of matter.

Cosmologically, the universe appears to contain far more matter than antimatter, a disparity known as baryon asymmetry. The origin of this imbalance remains uncertain, with theories invoking CP violation and processes in the early universe, such as baryogenesis. Experiments at facilities like CERN and elsewhere aim to produce and study antimatter more precisely, including the creation of antihydrogen and measurements of its properties. Observationally, antimatter is rare in interstellar space, though high-energy processes can generate antimatter in cosmic rays.