FeynRule[lag, {fields}] derives the Feynman rule corresponding to the field configuration fields of the lagrangian lag.
FeynRule does not calculate propagator Feynman rules.
The option ZeroMomentumInsertion can be used for twist-2 and higher twist operators.
See also: Lagrangian.
2-gluon Feynman rules (unpolarized)
2-gluon Feynman rules (polarized)
Compare with the Feynman rule tabulated in Twist2GluonOperator.
quark-quark Feynman rule (unpolarized)
quark-quark -gluon-gluon Feynman rule (unpolarized)
In general equality can be shown by Timing[Factor2[ FCE[Calc[ChangeDimension[FCE[OPESumExplicit[n4-t4]],4]/.s->-p-q-r]]]] but it is a little bit slow ...
QCD vertices
The FeynCalc Book | FeynCalcInternal | FieldStrength |