Name: zwhuang Date: 05/15/04-04:29:24 PM Z
Hi,
I have some questions about DiracTrace & TR functions. Here “t” and “s”
are only different in
the trace function DiracTrace or TR. By using OneLoop, I suppose the
result “rst1-rst2” should
be zero, but the output is not.
(****************************************************************************)
\!\(t = I\ \(el\^2\/\(16\ \(Pi\^4\) \((
1 - D)\)\)\) FAD[{q, mf}, {q - k, mf}]
DiracTrace[\((mf + GS[q -
k])\) . GA[¦Ì] . \((mf + GS[q])\) .
GA[¦Ì]]\ //
FCI\[IndentingNewLine]
s = I\ \(el\^2\/\(16\ \(Pi\^4\) \((1 - D)\)\)\)
FAD[{q,
mf}, {q - k, mf}] TR[\((mf + GS[q - k])\)
. GA[¦Ì] . \((mf +
GS[q])\) . GA[¦Ì]]\ // \ FCI\)
OneLoop[q, t]
rst1 = FullSimplify[%]
OneLoop[q, s]
rst2 = FullSimplify[%]
rst1 - rst2 // Simplify
(****************************************************************************)
The attachment is the full file (Trace.nb) with outputs.
Anther question is about the option “TraceOfOne”. FeynCalc sets
“TraceOfOne->4” in both
DiracTrace & TR functions in the usual cases. What I want to know is
wether I should
set “TraceOfOne->D” when I do some calculations in D-dimension.
Best regards,
Zhiwei Huang,
Wuhan University, PRC