Antiparticles

Antiparticles are subatomic particles that have the same mass as their corresponding particle but possess opposite charges and other quantum numbers, such as baryon number and lepton number. When a particle and its antiparticle meet, they can annihilate each other, resulting in the conversion of their mass into energy, typically in the form of photons or other particles. This fundamental concept is a cornerstone of particle physics, explaining phenomena like pair production and the behaviour of antimatter. The discovery of the positron (the electron's antiparticle) in 1932 confirmed Paul Dirac's prediction and ushered in a new era in understanding the universe's fundamental building blocks.

Antiparticles meaning with examples

• Scientists at CERN frequently collide particles and their Antiparticles, such as protons and antiprotons, in experiments like the LHC to study the effects of high-energy collisions and produce new particles. These collisions allow the creation of unusual particles as well as the formation of antiparticles. The detection of their decay products provides insight into the nature of these particles and their reactions with other particles.
• Positron Emission Tomography (PET) utilizes the annihilation of positrons (antimatter electrons) with electrons to create gamma rays. These gamma rays are then detected to create images of metabolic activity within the body, enabling medical diagnoses and research by tracking a drug, tagged with a radioactive isotope, which produces positrons that annihilate with electrons when it passes through an organ.
• In cosmic ray research, the detection of antiprotons and other Antiparticles provides clues about the origins of cosmic rays and possible sources of antimatter in the universe. These high-energy Antiparticles give clues to the mechanisms that propel them across space. Studying these components sheds light on energetic events beyond our solar system.
• The formation of an electron-positron pair from a high-energy photon is a classic example of particle-antiparticle creation. This pair creation demonstrates the equivalence of mass and energy, as predicted by Einstein's famous equation. The annihilation shows the complete conversion of mass into energy.