A proton and an antiproton at rest annihilate to create two gamma photons.The wavelength of the photons is

Question

Quizplus · Accepted Answer

The rest energy of a proton (or antiproton) is about 938 MeV. When they annihilate, the total energy is 2 * 938 MeV = 1876 MeV. Each photon carries half of this energy, so 938 MeV. Using E = hc/λ, where h is Planck's constant and c is the speed of light, the wavelength λ is approximately 1.32 fm.

A Proton and an Antiproton at Rest Annihilate to Create