In this Feynman diagram, an electron (e−) and a positron (e+) annihilate, producing a photon (γ, represented by the blue sine wave) that becomes a quark – antiquark pair (quark q, antiquark q̄), after which the antiquark radiates a gluon (g, represented by the green helix).

This is a list of common Feynman diagrams. His first published diagram appeared in Physical Review in 1949. [1] If neutrinos are Majorana fermions (that is, their own antiparticle), Neutrino-less double beta decay is possible. Several experiments are searching for this.

This diagram shows three basic actions. The first, a photon goes from place to place, is illustrated by the line from 5 to 6. The second, an electron goes from point A to point B in space-time, is illustrated by the lines from 1 to 5, 5 to 3, 2 to 6, and 6 to 4.

Photons are massless particles that can move no faster than the speed of light measured in vacuum. The photon belongs to the class of boson particles. As with other elementary particles, photons are best explained by quantum mechanics and exhibit wave–particle duality, their behavior featuring properties of both waves and particles. [2] .

A Feynman diagram serves two purposes: (1) it provides a simple graphical description of a physical process (including basic conservation laws) and (2) using a set of well-defined rules de- rived from quantum field theory, it allows a complete calculation of the “matrix element” f |M.

2024年12月23日 · A photon is created by the collision, and it subsequently forms two new particles in space: a muon (μ −) and its antiparticle, an antimuon (μ +). In the diagram of this interaction, both antiparticles (e + and μ +) are represented as their corresponding particles moving backward in time (toward the past).

Feynman devised a pictorial method for evaluating matrix elements for the interactions between fundamental particles in a few simple rules. We shall use Feynman diagrams extensively throughout this course. And each interaction point (vertex) with a • Each vertex contributes a factor of the coupling constant, g .

We make use of a graphical technique popularised by Richard Feynman1. Each graph – known as a Feynman Diagram – represents a contribution to M. fi. This means that each diagram actually represents a complex number (more generally function of the external momenta). The diagrams give a pictorial way to represent the contributions to the amplitude. (P

The inner wavy line represents a virtual photon. The interaction itself is represented by the point of intersection of an outer line with the inner one ( vertex of the diagram).

There's a scattering between an electron and a muon through the exchange of a photon. Both particles have electric charge of e. And then you can just calculate what is the probability for a process like