Name: Maksym Date: 08/19/17-08:37:03 PM Z
By the way, Feynman rules tell me that there must be GS[k1+k2]+mp.
Maybe similar question, but I don’t understand why the traces
DiracTrace[ComplexConjugate[QuarkPropagator[{p,
m}]]] /.
DiracTrace -> TR // Contract // Simplify
DiracTrace[QuarkPropagator[{p, m}]] /. DiracTrace -> TR
//
Contract // Simplify
give similar results (4im/(p^2-m^2)), while they must be different because of the sign.