1
$\begingroup$

When calculating a particle physics processes such as

$ a + b \rightarrow mediator \rightarrow c + d $

to do a Feynman diagram calculation we require the coupling between particle $a$, $b$ and the $mediator$ be small. This small is order 1. However is the upper limit of perturbativity 1, $\pi$, $2\pi$ or $4\pi$?

$\endgroup$
1

0

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.