SpinorChainChiralSplit[exp] introduces chiral projectors
in spinor chains that contain no \gamma^5.
Overview, DiracSubstitute67, DiracGamma, ToDiracGamma67.
SpinorUBar[p1, m1] . GSD[p] . SpinorV[p2, m2]
SpinorChainChiralSplit[%]\bar{u}(\text{p1},\text{m1}).(\gamma \cdot p).v(\text{p2},\text{m2})
\left(\varphi (\overline{\text{p1}},\text{m1})\right).(\gamma \cdot p).\bar{\gamma }^6.\left(\varphi (-\overline{\text{p2}},\text{m2})\right)+\left(\varphi (\overline{\text{p1}},\text{m1})\right).(\gamma \cdot p).\bar{\gamma }^7.\left(\varphi (-\overline{\text{p2}},\text{m2})\right)