FEYN CALC SYMBOL

CalcColorFactor


calculates the color factor of expr. CalcColorFactor is useful for application on FeynArts produced amplitudes. CalcColorFactor is just a macro function for CalcColorFactor[x_] := If[FreeQ2[FeynCalcInternal[x], SUNIndex], x, SUNSimplify[SUNSimplify[ (If[ !FreeQ[#1, DiracGamma], DiracTrick[#1], #1] & )[ SUNSimplify[x]], Explicit -> False], Explicit -> True]].