What is Fermi’s golden rule?
The transition rate from one state to another is proportional to the physics as drawn in the Feynman diagram
What particles do not decay?
Electron
Proton
Neutrino
What is the decay rate?
Γ=1/τ
So: N(t)=N(0)e^(-Γt)
How do we find the decay rate?
Find the characteristic decay rate for each channel and sum for all channels
What is the Branching fraction?
BF(i)=Γ_i/(∑r_i )=Γ_i/Γ_total