Questions tagged [feynman-diagrams]

A diagrammatic technique introduced by Richard Feynman to describe the quantum behaviour of subatomic particles and their interactions. Do not use for general questions on diagrams that are not of the Feynman kind.

799 questions
Filter by
Sorted by
Tagged with
61 views

Schrodinger equation vs Feynman diagrams

If one wants to assess how an electron orbits in a hydrogen atom one uses the Schrodinger equation. Ditto for an electron in a magnetic well. However if one wants to assess how particles interact or ...
85 views

How to solve integrals with $3$ Feynman parameters? [migrated]

I would like to evaluate integrals of the following type (in position space): $$\int \frac{d^{2\omega}z}{\left[(x_1-z)^2 (x_2-z)^2 (x_3-z)^2 \right]^A} \tag{1}$$ I can introduce three Feynman ...
29 views

60 views

131 views

Feynman rules of $\mathcal{N}=4$ supersymmetric Yang-Mills in Euclidean space

I am trying to derive the Feynman rules for $\mathcal{N}=4$ supersymmetric Yang-Mills. The (Euclidean) action that I start with comes from this paper (Wilson Loops in $\mathcal{N}=4$ Supersymmetric ...
13 views

What is the relationship between the cross section of two different mechanism that produce identical outcome?

I want to calculate the Compton collision cross section for a pair of entangled photons produced by two different mechanisms. Let mechanism A and B be different but both produce an identical outcome ...
43 views

Feynman diagram with polarized particles

While evaluating Feynman diagrams it's common to deal with unpolarized particles, meaning that we have to sum over the final particles and average over the initial ones: this is quite straightforward ...
63 views

89 views

Why only loop effects be quantum corrections when the full theory is quantum?

Feynman diagrams with one or more loops in an interacting QFT are diagrammatic representation of corrections to the Green's functions and amplitudes beyond the lowest order in perturbation theory (...
61 views

Does the W boson necessarily change an anti-fermion's flavor to its anti-neutrino counterpart?

I'm writing the diagrams for the following process in Standard Model: $$\nu_e + e^+\rightarrow \mu^++\nu_\mu+\gamma$$ I want to know if the W boson changes the flavor of $\mu^+$, for instance, ...
69 views

52 views

Question about Bhabha scattering Feynman Diagram

I'm a uni student going into his third year, and thought I might try to read through Griffith's particle physics textbook for the heck of it. I've been trying to become familiar with Feynman diagrams, ...