Name: Duarte (email_not_shown)
Date: 01/17/18-07:13:51 PM Z


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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