Srednicki — Quantum Field Theory · Problem 50.4

Canonical Quantization of Scalar Fields — Mark Srednicki

Physics — QFT · spinor-helicity-trace-identity

Problem

Show that

\langle p\,q\rangle[q\,r]\langle r\,s\rangle[s\,p] = \mathrm{Tr}\,\tfrac{1}{2}(1-\gamma_5)\not{p}\not{q}\not{r}\not{s} , \tag{50.37}

and evaluate the right-hand side.