Undergrad Calc QED Charge Particle Repulsion/Attraction

[ILoveParticlePhysics]

TL;DR

What is the formula for calculating the repulsion/attraction of charged particles in quantum electrodynamics?

Maybe this will help.

 

[vanhees71]

You just draw the Feynman diagram and calculute it according to the rules derived from the formalism. Feynman diagrams are just an ingenious shortcut to do these perturbative calculations. What you get are transition-matrix elements (S-matrix elements) from which you can calculate cross sections of scattering processes.

 

[Vanadium 50]

Note that you will need to calculate this to at least second order, because at leading order the scattering is the same either way.

 

[ILoveParticlePhysics]

You just draw the Feynman diagram and calculute it according to the rules derived from the formalism. Feynman diagrams are just an ingenious shortcut to do these perturbative calculations. What you get are transition-matrix elements (S-matrix elements) from which you can calculate cross sections of scattering processes.

So, I calculate and draw the Feynman diagram, from which I get the S matrix elements from which I get the cross section of scattering processes which tells me how everything is going to repel/attract, right?

 

[ILoveParticlePhysics]

Note that you will need to calculate this to at least second order, because at leading order the scattering is the same either way.

This might sound dumb, but what exactly is 2nd order.

 

[ILoveParticlePhysics]

Ok, I know I'm asking a lot of question, but I just want to confirm if this is an accurate source. https://arxiv.org/pdf/1602.04182

 

[vanhees71]

That looks like a good summary, but of course to really understand it, you should refer to some textbook on quantum field theory, e.g.,

M. D. Schwartz, Quantum field theory and the Standard
Model, Cambridge University Press, Cambridge, New York
(2014).

 

[Vanadium 50]

This might sound dumb, but what exactly is 2nd order.

Um, you haven't done any QED calculations, have you? It would be better for you to fill in your background than having me define words you don't understand with other words you don't understand. The easiest calculation is probably e+e- --> mu+mu-. I'd start there.