Griffiths Introduction to Elementary Particles · Problem 9.15

Weak Interactions — David J. Griffiths

Physics — QFT · qed-running-coupling-blowup

Problem

(a) Calculate the energy (

\sqrt{|q^2|c^2}

) at which the QED coupling constant (9.68) blows up. (Remember,

\alpha(0) =

the fine structure constant.) (b) At what energy do we get a 1\% departure from

\alpha(0)

? Is this an accessible energy?