Summary of the Course

We have given the rules for processes which involved a small number of particles. Since processes involving large numbers of particles can be understood in terms of the fundamental processes, we have in a sense described all of physics, as follows:

Rules to calculate im

Propagator:

spin 0

i/(p² – m²)

spin 1/2

i/ ( p   −   m ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429492501/e6a0c676-1f8d-4684-97a0-6bf3353f7ce0/content/eq770.tif"/>

photon

–(i/k²)

Electromagnetic coupling:

spin 1/2

− i ( 4 π ) 1 / 2 ev ¯ ε u https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429492501/e6a0c676-1f8d-4684-97a0-6bf3353f7ce0/content/eq771.tif"/>

spin 0

− i ( 4 π ) 1 / 2 e ( p 1   +   p 2 )   ⋅   ε   +   i 4 π e 2   ε 1   ⋅   ε 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429492501/e6a0c676-1f8d-4684-97a0-6bf3353f7ce0/content/eq772.tif"/>

β-decay coupling:

J*J