**Next message:**Vladyslav Shtabovenko: "Re: Wrong imaginary part of the trace"**Previous message:**Rolf Mertig: "Re: DiracTrace wrong result ?"**Next in thread:**Vladyslav Shtabovenko: "Re: Wrong imaginary part of the trace"**Reply:**Vladyslav Shtabovenko: "Re: Wrong imaginary part of the trace"**Maybe reply:**Nikita Belyaev: "Re: Wrong imaginary part of the trace"**Messages sorted by:**[ date ] [ thread ] [ subject ] [ author ]**Mail actions:**[ respond to this message ] [ mail a new topic ]

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

**Next message:**Vladyslav Shtabovenko: "Re: Wrong imaginary part of the trace"**Previous message:**Rolf Mertig: "Re: DiracTrace wrong result ?"**Next in thread:**Vladyslav Shtabovenko: "Re: Wrong imaginary part of the trace"**Reply:**Vladyslav Shtabovenko: "Re: Wrong imaginary part of the trace"**Maybe reply:**Nikita Belyaev: "Re: Wrong imaginary part of the trace"**Messages sorted by:**[ date ] [ thread ] [ subject ] [ author ]**Mail actions:**[ respond to this message ] [ mail a new topic ]

*
This archive was generated by hypermail 2b29
: 12/17/18-08:20:01 AM Z CET
*