Electron–positron annihilation

Collision causing gamma ray emission

Electron–positron annihilation occurs when an electron (e−) and a positron (e+, the electron's antiparticle) collide. At low energies, the result of the collision is the annihilation of the electron and positron, and the creation of energetic photons: e− + e+ → γ + γ At high energies, other particles, such as B mesons or the W and Z bosons, can be created. All processes must satisfy a number of conservation laws, including: Conservation of electric charge.

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