Hello everyone,
I'm evaluating the one-gluon-exchange tensor part of a phenomenological potential between two particles, and it involves a term like this:
S_{ij}=3(\vec{\sigma_i}\hat{r_{ij}})(\vec{\sigma_j}\hat{r_{ij}})-\vec{\sigma_i}\vec{\sigma_j}
With r_{ij} the unit vector in the...
Thank you very much, I think I got the point. However, I still have a further question. Here's what I've done:
-iM=(ie{\overline{u}^f}_A}\gamma^\mu u^i}_A) \frac{-ig_{\mu\nu}}{q^2}(ie{\overline{u}^f}_B}\gamma^\nu u^i}_B)=
= \frac{1}{q^2} \left( 1 + \frac{{p^f}_A {p^i}_A + i \sigma...
Hi everyone,
I'm studying electron-electron scattering, starting with the Dirac equation it ends up calculating the invariant transition amplitude, defined as:
-iM=(ie{\overline{u}^f}_A}\gamma^\mu u^i}_A) \frac{-ig_{\mu\nu}}{q^2}(ie{\overline{u}^f}_B}\gamma^\nu u^i}_B)
With u_A and u_B the...