Question

Normalising a massive propagator?

Answer 1

Explanation:

The propagator for a gauge boson in a gauge theory depends on the choice of convention to fix the gauge. For the gauge used by Feynman and Stueckelberg, the propagator.

Answer 2

Answer:

If you take a propagator Greens function for a massless photon from the origin as. G(0,x)=1x2−t2+iεG(0,x)=1x2−t2+iε