Antipartiklite

Antipartiklite are the counterpart particles in physics that possess the same mass and intrinsic properties as their corresponding particles but with opposite additive quantum numbers, such as electric charge or baryon and lepton numbers. For example, the antiparticle of the electron is the positron, which has the same mass but opposite electric charge. Antiparticles are predicted by relativistic quantum theory and quantum field theory, notably the Dirac equation, and they have been observed for all known fermions and many bosons. Some particles can be their own antiparticles, such as the photon, while others have distinct antiparticles depending on the theory and conservation laws.

Historically, antiparticles were proposed by Paul Dirac in 1928 and experimentally discovered in 1932 when Carl Anderson detected the positron in cosmic rays. Subsequent discoveries included the antiproton (1955) and the antineutron (1956). Today, antiparticles are routinely produced in particle accelerators and high-energy processes, often as particle–antiparticle pairs formed in pair production.

When a particle meets its antiparticle, annihilation typically occurs, converting the combined mass into energy in the form of gamma rays and other particles such as pions. Antiparticles thus play a central role in fundamental physics experiments, tests of symmetries like CPT invariance, and in studies of matter–antimatter asymmetry in the universe.

Applications include medical imaging, most notably positron emission tomography (PET), where positrons produced by radiotracers reveal metabolic processes. While antimatter is routinely produced in small quantities, storing and utilizing large amounts remains technologically challenging due to rapid annihilation with ordinary matter.