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)];
Tr2a = Tr[Q1.Q2.Q3.GA[i].(1 - GA)];
Tr3a = Tr[P1.P2.P3.GA[i].Q1.Q2.Q3.GA[i].(1 - GA)];
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) 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
This archive was generated by hypermail 2b29 : 03/28/17-03:40:01 PM Z CEST