Name: V. Shtabovenko Date: 01/18/18-03:41:04 AM Z


Hi,

could you provide a sample expression (minimal working example) which
causes the above mentioned problems?

Cheers,
Vladyslav

Am 18.01.2018 um 02:13 schrieb Duarte:
> Hi Vladyslav,
>
> many thanks for all the hard work here in Feyncalc forum.
>
> I’m having some problems with gamma5 in d dimensions. I know gamma5
> only makes sense at 4 dimensions; nonetheless, I need to evaluate some
> 1-loop amplitudes in dimensional regularization, and it turns out that
> those amplitudes involve gamma5.
>
> So I get two different error messages. One of them stems from my
> attempt to do a Contract involving d-dimensional gamma matrices and
> gamma5; “The problem reads: Incorrect combination of dimensions and
> g^5 scheme!”. The second one is equivalent, with the exception that
> instead of a Contract, I am trying to compute a trace; “the problem
> reads: Irregular trace structure in (…)”.
>
> I already tried some solutions (not successful, though). About the
> first problem: I read that you suggest using TID instead of OneLoop;
> but I don’t know how to make TID compute the loop integral (as OneLoop
> usually does). About the second one: I found out that one needs an
> additional prescription (in order to avoid troubles with gamma 5). So
> I chose the BHMV scheme; but the problem remains.
>
> Any suggestions?
>
> Thanks in advance,
> Duarte
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