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