Sorry for the typo. Should have been
amp = Pair[Momentum[k], Momentum[p1]]^3 FeynAmpDenominator[
PropagatorDenominator[k, lam], PropagatorDenominator[(k - q), lam],
PropagatorDenominator[(k - p1), m], PropagatorDenominator[(k +
and yes, there does seem to be a problem. I will investigate it.
Frederik Orellana wrote:
> I tried to reproduce this behaviour. An integrand corresponding to what
> you write would be:
> amp = Pair[Momentum[k], Momentum[p1]]FeynAmpDenominator[
> PropagatorDenominator[k, lam], PropagatorDenominator[(k - q), lam],
> PropagatorDenominator[(k - p1), m], PropagatorDenominator[(k +
> p2), M]];
> With this,
> OneLoop[k, amp]
> evaluates without problems.
> I need more details in order to help: Your integrand in FeynCalc
> notation; the version of FeynCalc you're using.
> Peter Blunden wrote:
>> I'm trying to do an integral that FeynCalc chokes on. The message
>> 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
>> 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)?
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