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Good day,

I've tried to calculate some matrix elements and I've faced with a bug.

As an example I can provide the following calculation.

Here are the well-known formula to calculate some trace combinations (FeynCalc syntaxis):

Tr1a = Tr[P1.P2.P3.GA[i].(1 - GA[5])];

Tr2a = Tr[Q1.Q2.Q3.GA[i].(1 - GA[5])];

Tr3a = Tr[P1.P2.P3.GA[i].Q1.Q2.Q3.GA[i].(1 - GA[5])];

Result = FullSimplify[Contract[Tr1a.Tr2a + 2 Tr3a]];

P1,...,Q1,... are dirac slashed values.

Result should be zero, but in FeynCalc there is a bug with calculating of Tr[P1.P2.P3.GA[i].Q1.Q2.Q3.GA[i].GA[5]) term. The result contsins wrong imaginary combination of Levi-Civita symbols (there are 15 terms instead of 6), real part is zero.

So what is the reason for that?

I can provide any files you might need.

P.S. FeynCalc 8.2.0, Mathematica 9

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