Understanding Counterterms: Demystifying Srednicki's Equation 9.25

[malawi_glenn]

Hi, I was wonder what mr. Srednicki is meaning on page 68 (page 82 in his pre-print), where he writes that "Eq. 9.25" results in a new vertex where two lines meet" Now I have a hard time to figure it out how it would look like diagrammatically and was wondering if anyone had a more hands-on example?

cheers

 

[Avodyne]

The corresponding diagram is the second one in figure 14.1.

 

[malawi_glenn]

Thanx mate!

I have a hard time to appreciate Srednicki, the reviews on Amazon is very good. But I think that sometimes, it the worst textbook I have read. So I have this hate-love relation to him. Same with Peskins book... but in the end, I think Peskin and Srednicki complements each other very well.