antideeltje

An antideeltje, in Dutch usage, is the antiparticle of a given subatomic particle. An antideeltje, or antiparticle, has the same mass as its partner but opposite charges and other quantum numbers. The concept follows from relativistic quantum mechanics and the CPT theorem, which implies that every particle has a corresponding antiparticle with identical mass and lifetime but opposite charge and related quantum properties.

Key properties include mass equality and opposite conserved quantities. For example, an electron and a positron share the same mass, but the positron carries opposite electric charge and opposite lepton-number sign. Antideeltjes can be produced in high-energy processes through pair production and can be created in pairs so that overall quantum numbers are conserved. When an antideeltje meets its corresponding particle, annihilation typically occurs, converting their mass into energy in the form of photons or other particles. This annihilation energy is governed by E = mc^2, such as the electron-positron case yielding gamma photons with a total energy of 2 m_e c^2.

Historically, the positron—the antiparticle of the electron—was predicted by Dirac and discovered in 1932, confirming the antiparticle concept. The antiproton was discovered in 1955, followed by observations of antineutrons. Today, antideeltjes are routinely produced in accelerators and used in various applications, including medical imaging with positron emission tomography (PET). They also play a central role in fundamental physics research on matter–antimatter symmetry and the observed dominance of matter in the universe.