Name: Van der Ventel BIS Date: 03/26/04-02:21:42 PM Z
Dear Feyncalc users
I am experiencing the following problems and would greatly appreciate any assistance. I have MATHEMATICA 5 on my linux system (mandrake) and I’ve noticed the following:
1. I installed the following version of FeynCalc:
HighEnergyPhysics-4.1.1.0.tar.gz. When I type
<<HighEnergyPhysics`FeynCalc` then it generates the following
messages:
Tag Re in -Re[HighEnergyPhysics`qcd`OPEi`OPEi] +
Re[OPEm] > 0
is too deep for an assigned rule to be found.
TagSet::tagpos:
Tag Re in -Re[HighEnergyPhysics`qcd`OPEi`OPEi] +
Re[OPEm] > 1
is too deep for an assigned rule to be found.
TagSet::tagpos:
Tag Re in -Re[HighEnergyPhysics`qcd`OPEi`OPEi] +
Re[OPEm] > 2
is too deep for an assigned rule to be found.
General::stop: Further output of TagSet::tagpos
will be suppressed during this calculation.
FeynCalc4.1.1 Type ?FeynCalc for help or visit
http://www.feyncalc.org
$PrePrint is set to FeynCalcForm. Use FI and FC to change the
display format.
What does this all mean?
2. When I then try to calculate the following leptonic tensor:
Tr[\gamma^{\mu}(1-\gamma^{5}).DiracSlash[k].(1+\gamma^{5}).\gamma^{\nu}.(1-\gamma^{5}).DiracSlash[p].(1+\gamma^{5})]
it gives me the wrong sign for the ant-symmetric part: \epsilon^{\mu
\nu \alpha \beta} k_{\alpha} p_{\beta}, i.e., I get a positive
sign, instead of a negative sign.
3. I then installed fc5beta1.tar.gz
Now, the error messages mentioned in no. 1 above no longer appear, but
when I try and calculate the leptonic tensor, then it does not even give
the anti-symmetric part!
Any help would be wonderful.
Thank you!
Brandon van der Ventel
Physics Department
Stellenbosch University
South Africa