Name: Vladyslav Shtabovenko (email_not_shown)
Date: 01/17/17-10:40:48 AM Z


It works, but when GaugeXi is not 1 you end up with propagators raised
to integer powers that require IBP reduction to be further simplified.
For example,

FAD[{q, m, 4}]

is just a tadpole raised to 4th power, but without IBP FeynCalc would
write it as a D-function

OneLoop[q, FAD[{q, m, 4}]]

I \[Pi]^2 D0[0, 0, 0, 0, 0, 0, m^2, m^2, m^2, m^2]

which is clearly an overkill.

Have a look at

https://github.com/FeynCalc/feynhelpers/blob/master/Examples/QCD/QCDThreeGluonVertexOneLoop.m

for some ideas how to deal with such integrals using FeynHelpers. TID
is way more convenient for that than OneLoop.

Cheers,
Vladyslav

> The FeynCalc Manual has the following note about the OneLoop function:
>
> NOTICE: While OneLoop is restricted to 't Hooft Feynman....
>
> In what sense ithe OneLoop resticted to the t'Hooft gauge _GaugeXi->1? Does it also work in the physical gauge _GaugeXi->0? Could you give an example in general gauge that OneLoop cannot handle?
>
> Many thanks
> Jon Palmer



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