Date: 05/05/17-09:59:47 PM Z

Which FeynCalc version?

With the current stable version (9.2) I get:

<< FeynCalc`

res = ToFI[(32 CA^3 mE^2 FeynAmpDenominator[
PropagatorDenominator[Momentum[p1, D]],
PropagatorDenominator[Momentum[p2, D], I mE],
PropagatorDenominator[-Momentum[p1, D] + Momentum[p2, D],
I mE], PropagatorDenominator[-Momentum[p1, D] +
Momentum[p2, D], I mE],
PropagatorDenominator[-Momentum[p1, D] + Momentum[p2, D],
I mE]] Pair[Momentum[p1, D], Momentum[q, D]] Pair[
Momentum[p2, D],
Momentum[q,
D]] (-Pair[LorentzIndex[Lor1, D], Momentum[q, D]] Pair[
LorentzIndex[Lor2, D], Momentum[q, D]] +
Pair[LorentzIndex[Lor1, D], LorentzIndex[Lor2, D]] Pair[
Momentum[q, D], Momentum[q, D]]) SMP["g_s"]^6 Subscript[
zeta, 1] SUNDelta[SUNIndex[a], SUNIndex[b]])/((-1 + D) Pair[
Momentum[q, D], Momentum[q, D]]) // Expand, {p1, p2}, {q}]

res

(32*CA^3*mE^2*SD[a, b]*SMP["g_s"]^6*(-(FVD[q, Lor1]*FVD[q, Lor2]) +
MTD[Lor1, Lor2]*SPD[q, q])*Subscript[zeta, 1]*
TFI[D, SPD[q, q], {0, 0, 1, 1, 0}, {{1, 0}, {1, I*mE}, {0, 0}, {0, 0},
{3, I*mE}}])/((-1 + D)*SPD[q, q])

TarcerRecurse[res]

(-2*CA^3*(-6 + D)*(-2 + D)*SD[a, b]*SMP["g_s"]^6*
(FVD[q, Lor1]*FVD[q, Lor2] - MTD[Lor1, Lor2]*SPD[q, q])*
Subscript[zeta, 1]*TAI[D, 0, {{1, I*mE}}]^2)/((-1 + D)*D*mE^2)

Cheers,

Am 05.05.2017 um 18:03 schrieb Philipp Schicho:
> I am trying to convert certain two-loop integrals into TFI notation. Surprisingly this works for certain integrals while others keep returning a product over variables like Feyncalc`ToTFI`Private` this is not even consistent as it keeps changing.
>
>
> For example the following expression
>
> ToFI[(32 CA^3 mE^2 FeynAmpDenominator[PropagatorDenominator[Momentum[p1,D]],PropagatorDenominator[Momentum[p2,D],I mE],PropagatorDenominator[-Momentum[p1,D]+Momentum[p2,D],I mE],PropagatorDenominator[-Momentum[p1,D]+Momentum[p2,D],I mE],PropagatorDenominator[-Momentum[p1,D]+Momentum[p2,D],I mE]] Pair[Momentum[p1,D],Momentum[q,D]] Pair[Momentum[p2,D],Momentum[q,D]] (-Pair[LorentzIndex[Lor1,D],Momentum[q,D]] Pair[LorentzIndex[Lor2,D],Momentum[q,D]]+Pair[LorentzIndex[Lor1,D],LorentzIndex[Lor2,D]] Pair[Momentum[q,D],Momentum[q,D]]) SMP["g_s"]^6 Subscript[zeta, 1] SUNDelta[SUNIndex[a],SUNIndex[b]])/((-1+D) Pair[Momentum[q,D],Momentum[q,D]])//Expand,{p1,p2},{q}]
>
> resulted in
>
> (1/((D-1) q^2))32 mE^2 Subscript[zeta, 1] Subsuperscript[C, A, 3] Subsuperscript[g, s, 6] \[Delta]^(ab) (q^2 g^(Lor1Lor2)-q^Lor1 q^Lor2) FeynCalc`ToTFI`Private`dq1^FeynCalc`ToTFI`Private`a1.FeynCalc`ToTFI`Private`dq2^FeynCalc`ToTFI`Private`a2.FeynCalc`ToTFI`Private`pq1^(FeynCalc`ToTFI`Private`s3+1).FeynCalc`ToTFI`Private`pq2^(FeynCalc`ToTFI`Private`s4+1).FeynCalc`ToTFI`Private`q1q1^FeynCalc`ToTFI`Private`s1.FeynCalc`ToTFI`Private`q1q2^FeynCalc`ToTFI`Private`s5.FeynCalc`ToTFI`Private`q2q2^FeynCalc`ToTFI`Private`s2.FeynCalc`ToTFI`Private`c1(0)^(FeynCalc`ToTFI`Private`n1+1).FeynCalc`ToTFI`Private`c1(I mE)^(FeynCalc`ToTFI`Private`n1+1).FeynCalc`ToTFI`Private`c2(FeynCalc`ToTFI`Private`FakeMass)^(FeynCalc`ToTFI`Private`n2+1).FeynCalc`ToTFI`Private`c3(FeynCalc`ToTFI`Private`FakeMass)^(FeynCalc`ToTFI`Private`n3+1).FeynCalc`ToTFI`Private`c4(FeynCalc`ToTFI`Private`FakeMass)^(FeynCalc`ToTFI`Private`n4+1).FeynCalc`ToTFI`Private`c5(I mE)^(FeynCalc`ToTFI`Private`n5+3)
>
> Maybe someone can help me with this. Frankly I am quite los atm.
>
> Cheers,
> Philipp
>

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