Name: rolf@mertig.com (email_not_shown)
Date: 03/27/03-01:42:52 AM Z


First a remark: All these so-called Gamma5 schemes are not
very clear and solid, so the best is to just avoid
having to calculate traces with 6 or more gamma matrices
and gamma5. This can be done with a tensorial decomposition
as described in
Zeitschrift für Physik C
Year: 1996
Volume: 70
Page range: 637-653

The functions in FC to do this are:http://www.feyncalc.org/FeynCalcBook/TIDL
and
http://www.feyncalc.org/FeynCalcBook/TID
and also (only one-loop) OneLoopSimplify.

Having said that, yes, sometimes there seems to be no
way out or things are easier or whatever and you do
want traces of 6 gammas and gamma5 in D dimensions.
And yes, you found a bug. Thanx.
I fixed it.
Until it gets into the next official version (you are
welcome to help Frederik to do this) everybody can
replace their FeynCalc.m by
http://www.mertig.com/FeynCalc0327.m
(rename to FeynCalc.m, but maybe save the old one).

In[1]:= <<HighEnergyPhysics`fc`

FeynCalc4.1.2 Type ?FeynCalc for help or visit http://www.feyncalc.org
$PrePrint is set to FeynCalcForm. Use FI and FC to change the display format.

In[2]:= GAD[e,f,5,a,b,c,d]//DiracTrace//DiracSimplify

Out[2]= tr[ga[a] ga[b] ga[c] ga[d] ga[e] ga[f] ga[5]]

Regards,

Rolf Mertig
Mertig Consulting
http://www.mertig.com
http://www.mathxls.com



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