Name: Frederik Orellana Date: 06/21/03-01:28:04 PM Z


Hi.

FeynCalc returns results in terms of CA and CF (try ?CA and ?CF), or N if
you set SUNNToCACF -> False.
The following will return what you want if you replace N with 3.

l2 // SUNSimplify[#, SUNNToCACF -> False] &

For explicit SU(2) and SU(3) calculations you might want to enable the
subpackage PHI (do $LoadPhi=True before loading FeynCalc). Then you can use
SUNReduce.

Frederik

At 14:52 20-06-2003 -0400, you wrote:

>Hi,
>
>I am trying to use feyncalc to do an explicit sum over trace of the
>generators of SU(3). Something like the following (which does not work).
>
>————————————————————-
>In[1]:=
><<HighEnergyPhysics`FeynCalc`
>
>In[2]:=
>
>l1 = SUNT[a].SUNT[a]
>
>
>In[3]:=
>
>l2 = SUNTrace[l1]
>
>Out[3]=
>\!\(\*FormBox[
> FractionBox[
> SubscriptBox[”\[Delta]”,
> RowBox[{
> FormBox[
> FormBox[“a”,
> “TraditionalForm”],
> “TraditionalForm”], “\[NoBreak]”,
> FormBox[
> FormBox[“a”,
> “TraditionalForm”],
> “TraditionalForm”]}]], “2”], TraditionalForm]\)
>—————————————————————
>
>How can I use feyncalc to actually do this explicit sum over trace for
>SU(3) and give me output 4 at the end
>
>
>thanks,
>sameer