Positrons are the antiparticles of electrons. While electrons carry a negative electric charge (−1), positrons have the same mass as electrons but possess a positive electric charge (+1).
Discovered in 1932 by Carl Anderson through cosmic ray experiments, positrons are a key prediction of Paul Dirac’s theory, which combined quantum mechanics and special relativity and predicted the existence of antimatter.
When a positron encounters an electron, the two can annihilate, converting their mass into energy in the form of gamma-ray photons. This annihilation process is the basis for technologies such as positron emission tomography (PET) used in medical imaging.
Key points about positrons:
- They have identical mass and spin to electrons,
- They behave like electrons but with opposite charge,
- They can be produced in certain types of radioactive decay or high-energy interactions,
- Their existence confirms the symmetry between matter and antimatter predicted by modern physics.
Positrons help physicists explore fundamental symmetries of nature and have practical applications in science and medicine, illustrating the deep relationship between matter and antimatter.