Name: Vladyslav Shtabovenko Date: 05/18/17-02:58:15 PM Z


Hi,

thanks for the bug report. It is a bug that affects terms like
(L1 GA[7] + R1 GA[6]) where both projectors appear multiplied with
different constants. Should be now fixed. Please reinstall FeynCalc 9.2
and let us know if you encounter any further issues.

Cheers,
Vladyslav

Am 17.05.2017 um 11:02 schrieb Ula:
> Dear FeynCalc users,
>
> In ``official” FeynCalc examples the identity matrix is not used under the trace. However, it seems that sometimes this yields wrong results when chiral projectors are present. Is this an expected bahavior, or I am doing something wrong? (I’m using FeynCalc 9.2.0 with Mathematica 8.0.4.)
>
> (*Definitions*)
>
> In[2]:= ID = GA[6] + GA[7];
>
> In[3]:= y1 = L1 GA[7] + R1 GA[6];
>
> In[4]:= y2 = L2 GA[7] + R2 GA[6];
>
>
> (*Worng result*)
>
> In[5]:= Tr[y1.(GS[p2] + m2).y2.(GS[p1] - m1)] // FCE
>
> Out[5]= -2 (L2 R1 + L1 R2) (m1 m2 - SP[p1, p2])
>
> (*Correct result*)
>
> In[6]:= Tr[y1.(m2).y2.(-m1)]
>
> Out[6]= -2 m1 m2 (L1 L2 + R1 R2)
>
>
> (*Correct result*)
>
> In[7]:= Tr[y1.(GS[p2] + m2 ID).y2.(GS[p1] - m1 ID)] // Simplify // FCE
>
> Out[7]= -2 m1 m2 (L1 L2 + R1 R2) + 2 (L2 R1 + L1 R2) SP[p1, p2]
>
>
> Thanks and best wishes,
> Ula
>