Slide 18 of 48
Notes:
An electron-positron pair can be created when a gamma-ray collides with another photon. In the process, the gamma-ray is absorbed.
In the coming viewgraphs, we will derive the minimum energy of the gamma-ray required for this process to occur. Theta is the angle between the two colliding photons - and we will be resolving components of the momentum vectors onto two mutually orthogonal vectors, x and y, as shown.
