Daily Archives: July 22, 2007

Feynman Diagrams for the Masses (part 1)

If you want to win a Nobel Prize in Physics by finding the unified field theory, it’s pretty obvious that you will have to learn how to make Quantum field theory (QFT) calculations. In the 1940s, Richard Feynman and Ernest Stueckelberg independently developed a notation (now known as Feynman Diagrams), that greatly ease certain calculations in QFT.

Julian Schwinger complained that Feynman had made QFT accessible to the “masses”. He meant the “masses of physicists.” Between this post and the next, we’re going to take Feynman one better and make Feynman diagrams accessible to the masses, as in “masses of amateurs.” Our simplification will be to use qubits. For a reference in the arXiv literature, see Quantum Electrodynamics for Qubits, but our discussion will be simpler than this. This post will discuss Feynman diagrams the usual way.

I will try to write this introduction at a low enough level, and with enough links to explanations of the jargon, that it can be understood by people unfamiliar with particle physics. Accordingly, we will skim over a lot of details, but will include links to articles that will explain further, if needed.
Photon self energy by electron positron pair production
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