First steps with Feynman diagrams

[Rick16]

Homework Statement

Draw all the fourth-order (four vertex) diagrams for Compton scattering. (There are 17 of them; disconnected diagrams and "tadpoles"--photon lines terminating in an electron loop--don't count.)

Relevant Equations

no equations

This is problem 2.3 in Griffiths' Introducion to Elementary Particles. I have Griffiths' solutions, otherwise I would be completely lost. Nonetheless, I tried to come up with a solution of my own first. I found only one possibility, which looked ok to me, but it is not even among the 17 ones that Griffiths shows. Here is mine:

What is wrong with it?

 

[haushofer]

It has been a while for me, but I also don't see what's wrong with it. Every vertex should contain two electron lines and one photon line. But I also haven't seen all of the 17 diagrams, so maybe one of them is topologically the same as the one you drew?

 

[renormalize]

View attachment 373752
What is wrong with it?

As @haushofer says, it's correct. Consider this example I found online, more or less at random:

(https://arxiv.org/pdf/hep-ph/9801260)
Your drawing is diagram (e).

 

[Rick16]

Your drawing is diagram (e).

Yes, that is mine. I just cannot find anything resembling that one among Griffiths' diagrams. Or could it perhaps be this one: