What process does this Feynman diagram represent?
A Feynman diagram represents a perturbative contribution to the amplitude of a quantum transition from some initial quantum state to some final quantum state. For example, in the process of electron-positron annihilation the initial state is one electron and one positron, the final state: two photons.
What idea did Richard Feynman introduce to help describe the interaction between two particles?
quantum electrodynamics (QED), quantum field theory of the interactions of charged particles with the electromagnetic field. It describes mathematically not only all interactions of light with matter but also those of charged particles with one another.
What did Richard Feynman invent?
Along with his work in theoretical physics, Feynman has been credited with pioneering the field of quantum computing and introducing the concept of nanotechnology. He held the Richard C. Tolman professorship in theoretical physics at the California Institute of Technology.
What is a connected Feynman diagram?
7. Connected Diagrams. Diagrams with just one component are called connected diagrams. They have no discon- nected vacuum components so they contribute to what are called connected Green functions.
Is Feynman propagator symmetric?
(Feynman propagator is symmetric) The Feynman propagator ΔF (def. ) is symmetric: ΔF(x,y)=ΔF(y,x).
What was Feynman famous for?
Richard Feynman is famous for his work on quantum electrodynamics, which describes how light interacts with matter and how charged particles interact with each other.
Why does Wick rotate?
Wick rotation is called a rotation because when we represent complex numbers as a plane, the multiplication of a complex number by i is equivalent to rotating the vector representing that number by an angle of π/2 about the origin.
What is the Feynman diagram of the electron?
Feynman diagram. In this Feynman diagram, an electron and a positron annihilate, producing a photon (represented by the blue sine wave) that becomes a quark–antiquark pair, after which the antiquark radiates a gluon (represented by the green helix).
Is the Feynman diagram of the positron accurate?
In that sense the Feynman diagram is not a mere visual aid, but accurately reflects the physics. Under normal conditions that implies that the positron is going backwards in time, BUT we must always remember that spacetime cannot be subjected to anthropomorphic visualisation in which man’s universal time plays the chief role.
What is the Feynman diagram for quarks and quarks?
In this Feynman diagram, an electron and a positron annihilate, producing a photon (represented by the blue sine wave) that becomes a quark–antiquark pair, after which the antiquark radiates a gluon (represented by the green helix).
How are antiparticles represented in Feynman diagrams?
Feynman used Ernst Stueckelberg’s interpretation of the positron as if it were an electron moving backward in time. Thus, antiparticles are represented as moving backward along the time axis in Feynman diagrams.
