Name: Shrihari Date: 02/11/14-02:59:42 PM Z
Hi,
I am having some problems getting OneLoop[…] to work. I give below a simplified example, where I think (part of) my problem lies.
I notice that OneLoop[…] does not cancel the two terms in:
( 4 (l^mu l^nu) - l^2 g^(mu nu) )/f(l^2) where f is symmetric in l.
The result should be zero.
I have a small test code to show this, given below.
I expect the results Res1 and Res2 to be the same.
Res2 is ok while Res1 seems to have another term.
Am I doing something wrong?
I don’t seem to be able to attach a file to this email (through the
web-interface), so have placed the Mathematica notebook at:
http://www.imsc.res.in/~shri/testFeynCalc.nb
Thanks for any help.
Shrihari
-———————
(* The notebook file at the above link also contains the results.
Res1 and Res2 should be the same, but don’t seem to be. *)
tst = FeynAmpDenominator[
PropagatorDenominator[Momentum[l, D],
Sqrt[mf^2]],
PropagatorDenominator[Momentum[l, D],
Sqrt[mf^2]],
PropagatorDenominator[Momentum[l, D],
Sqrt[mf^2]]]*(mf^3*
Pair[LorentzIndex[\[Mu], D],
LorentzIndex[\[Nu], D]] +
4*mf*Pair[LorentzIndex[\[Mu], D],
Momentum[l, D]]*
Pair[LorentzIndex[\[Nu], D], Momentum[l,
D]] -
mf*Pair[LorentzIndex[\[Mu], D],
LorentzIndex[\[Nu], D]]*
Pair[Momentum[l, D], Momentum[l, D]])
Res1=PaVeReduce[OneLoop[l, tst]]
tst2 = FeynAmpDenominator[
PropagatorDenominator[Momentum[l, D],
Sqrt[mf^2]],
PropagatorDenominator[Momentum[l, D],
Sqrt[mf^2]],
PropagatorDenominator[Momentum[l, D],
Sqrt[mf^2]]]*(mf^3*
Pair[LorentzIndex[\[Mu], D],
LorentzIndex[\[Nu], D]])
Res2 = OneLoop[l, tst2]
-—————- end ———