Hello again,(adsbygoogle = window.adsbygoogle || []).push({});

I also have another question, somewhat related to my previous, on the topic of the Klein-Gordon equation but treating the mass as a perturbation.

The feynman diagram shows the particular interaction:

I believe the cross is the point of interaction via the perturbation (the mass), we model the perturbation:

[tex]\delta V=m^2[/tex]

and subsequently use this in the calculation for the transition amplitude, we use plane-wave solutions of the ingoing and outgoing states.

Alike to my previous question, I'm not really sure what this means to model some potential as a mass? Can anyone explain why we do this and maybe exactly what is happening in this particular feynman diagram?

I can try to embelish if needs be, please tell me if there are any inconsistencies or errors I have made in my explanation of my problem!

Thanks,

SK

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Treating Mass as a perturbation

**Physics Forums | Science Articles, Homework Help, Discussion**