Treat Problem 15.2 without the assumption of nonrelativistic motion, using (15.2) and assuming the elastic impact is of negligible duration. Show that the cross section for photon emission is now
dΩd(ℏω)d2σ=4πR2ℏce2ℏωβ2[(1−βcosθ)2sin2θ+β31ln(1−β1+β)−β22]