- #26

nrqed

Science Advisor

Homework Helper

Gold Member

- 3,764

- 294

thanks for the response! yes, I realized I miss-used the expression cross section and replaced it with amplitude. I thought the two processes were related due to their similarity when drawing Feynman diagrams but wasnt sure, thanks for clarifying.

Just for further understanding... can we say that the cross section is proportional to [tex]G^2 E_{cm}^2[/tex] since [tex]\bar{M^2}= 64G^2 (p \cdot k')(p' \cdot k) [/tex]? If so, then we can say that [tex]\frac{d \sigma}{dE_{cm}^2} =const[/tex] and then could we say that it is safe to assume that the total cross section approaches infinity as [tex]E_{cm}[/tex] increases?

I don't have time to check now but how did you get that the cross section is proportional to G^2 E_{cm}^2 (it might be obvious but I don't see). Did you include the phase space factors (which tend to suppress the cross sections)