Name: Peter Blunden (email_not_shown)
Date: 03/18/03-12:59:18 AM Z

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,
which one)?

This archive was generated by hypermail 2b29 : 11/20/18-04:40:01 PM Z CET