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.