Name: Pietro Dall’Olio Date: 10/31/13-06:29:29 PM Z
Hi. I’m using FeynCalc 8.2.0. I write the following:
$LoadFeynArts = False;
«HighEnergyPhysics`FeynCalc`
Contract[a_, b_, o___?OptionQ] :=
Contract[a*b, o] /;
FreeQ[a, Plus] || FreeQ[b, Plus] || LeafCount[{a,
b}] < 1000;
SetOptions[OneLoop, Dimension -> D];
integral =
Contract[(MetricTensor[eta, la, Dimension -> D]
FourVector[l, si,
Dimension -> D] +
MetricTensor[eta, si, Dimension -> D] FourVector[p,
la,
Dimension -> D] -
MetricTensor[si, la, Dimension -> D] FourVector[p,
eta,
Dimension -> D]) (-PolarizationSum[eta, eps, l,
Dimension -> D]*
ScalarProduct[l, l,
Dimension ->
D]) (-MetricTensor[eps, ga, Dimension -> D]
FourVector[k, be,
Dimension -> D] +
MetricTensor[eps, be, Dimension -> D] FourVector[l,
ga,
Dimension -> D] +
MetricTensor[be, ga, Dimension -> D] FourVector[k,
eps,
Dimension -> D]) (-PolarizationSum[al, be, l - k,
Dimension -> D]*
ScalarProduct[l - k, l - k,
Dimension -> D]) (MetricTensor[de, al,
Dimension -> D] FourVector[(l - k), xi, Dimension ->
D] -
MetricTensor[de, xi, Dimension -> D] FourVector[(p +
k), al,
Dimension -> D] +
MetricTensor[xi, al, Dimension -> D] FourVector[(k +
p), de,
Dimension -> D]) (-PolarizationSum[de, la, p + l,
Dimension -> D]*ScalarProduct[p + l, p + l, Dimension
-> D])]
-I/Pi^2*OneLoop[l,
FeynAmpDenominator[PD[(p + l), 0], PD[(k - l), 0],
PD[l, 0]]*
integral, CancelQP -> True, OneLoopSimplify -> True]
Everything works fine. But now if I try to evaluate the same integral,
but putting a mass to one of the propagators in FAD, it gives me:
FYI: Tensor integrals of rank higher than 3 encountered; Please use the
option CancelQP -> True or OneLoopSimplify->True or use another
program.
Could you help me out? Thank you very much!
Pietro