Griffiths Introduction to Elementary Particles · Problem 7.35

Electrodynamics of Quarks and Hadrons — David J. Griffiths

Physics — QFT · electron-muon-scattering-cross-section

Problem

(a) Starting with equation (7.126), find the spin-averaged amplitude for electron-muon scattering in the

CM

frame, in the high-energy regime (

m, M \to 0

). (b) Find the

CM

differential cross section for electron-muon scattering at high energy. Let

E

be the electron energy and

\theta

the scattering angle.

\left[\textit{Answer: }\frac{d\sigma}{d\Omega} = \left(\frac{\hbar c}{8\pi}\right)^2\frac{g_e^4}{2E^2}\left(\frac{1+\cos^4\theta/2}{\sin^4\theta/2}\right)\right]