I'm trying to do an integral that FeynCalc chokes on. The message returned
is the usual
FYI: Tensor integrals of rank higher than 3 encountered; Please use the
option CancelQP -> True or OneLoopSimplify->True or use another program.
However, it appears that CancelQP->True is the default, and OneLoopSimplify
expresses the results in terms of Contract3, which doesn't seem to exist.
The integrals are box diagrams, and a typical term would look something like
(k.p1)^3 / [k^2-lam^2][(k-q)^2-lam^2][(k-p1)^2-m^2][(k+p2)^2-M^2]
where p1^2=m^2 and p2^2=M^2. This term looks innocent enough, and in fact
looks to me like it IS of rank 3. By a lot of fudging and manipulating I
managed to get a result using ScalarProductCancel, but it is hit and miss
for various terms in the amplitude.
Is there a fix in FeynCalc, or do I have to use another program (and if so,
This archive was generated by hypermail 2b29 : 11/22/17-05:20:01 PM Z CET