# Feynman Propagators

1. Jan 11, 2012

### ryanwilk

Hi, this is probably very simple but what is the difference between these two Feynman propagators:

$$\frac{i}{q^2-m^2}$$
$$\frac{i(p/+m)}{p^2-m^2}$$

E.g. Is one used for the invariant amplitude and the other for loop integrals? Or is one for a fermion and the other for a boson? =s

Thanks!

Last edited: Jan 11, 2012
2. Jan 11, 2012