Name: V. Shtabovenko Date: 05/31/19-07:42:02 PM Z


Hi,

please do not mix 4- and D-dimensional quantities when using naive
dimensional regularization, as this is not well-defined.

Cf. also

https://github.com/FeynCalc/feyncalc/wiki/FAQ#g5ddim

Cheers,
Vladyslav

Am 30.05.19 um 16:16 schrieb Maksym Ovchynnikov:
> Hi!
>
> I tried to simplify the following expression:
>
> Amplitude1 =
> DiracSimplify[
> I*(e*g^2)/
> 8 (MetricTensor[\[Kappa], \[Lambda]] (ScalarProduct[k,
> k] - \[Alpha] mW^2) -
> FV[k, \[Kappa]] FV[k, \[Lambda]]) DiracMatrix[\[Kappa]].(1 -
> DiracMatrix[5]).(GSD[pprime] - GSD[k] +
> ml).DiracMatrix[\[Mu]].(GSD[pprime] - GSD[k] +
> ml) DiracMatrix[\[Lambda]].(1 - DiracMatrix[5]) FAD[{k,
> Sqrt[\[Alpha]] mW}, {pprime - k, ml}, {p - k, ml}, {k, mW}]]
>
> However, there is an error:
>
> “DiracTrick::failmsg: Error! DiracTrick has encountered a fatal problem and must abort the computation. The problem reads: Incorrect combination of dimensions and g^5 scheme!”
>
> What is a reason for this?
>