Srednicki — Quantum Field Theory · Problem 81.2

Canonical Quantization of Scalar Fields — Mark Srednicki

Physics — QFT · scattering-qcd

Problem

Compute the

\bar{q}qgg

partial amplitude

A(1^-_{\bar{q}}, 2^+_q, 3^-, 4^+)

with

q_4 = p_1

and

q_3 = k_4

. Show that, with this choice of the reference momenta, the first line of eq. (81.47) vanishes. Evaluate the second line, and verify eq. (81.55).