On Mon, 20 Aug 2001, Rolf Mertig wrote:
> Hi,
> you can try to either use OneLoopSimplify (though it will take longer) or
> play with the option $LimitTo4 (or similiar).
> You may also send one typical amplitude but I won't promise I have time to
> look at it ...
>
> Rolf Mertig
>
> P.s.: I am no professor. I was a postdoc and left physics research 5 years
> ago.
>
> On Monday 20 August 2001 08:28 pm, you wrote:
> > Dear Professor Mertig
> >
> > I've been using FeynCalc4.0.2 to calculate one loop
> > corrections to strong interaction processes involving QCD and SUSY-QCD
> > spectrum and I've chosen to work with dimensional regularization.
> >
> > However I have found some problems with the PaVeReduce
> > routine in D dimensions. Even after set the PaVeReduce options, choosing
> > Dimension -> D, the output always comes in 4 dimensions.
> >
> > Besides, I've realized the OneLoop function returns all
> > D-dimensional objects like four vectors, dirac matrices, dirac slashes,
> > etc in 4 dimensions.
> >
> > Could you tell me how to set the right options in such way
> > that everything may be calculated in D-dimensions?
> >
> >
> > Thank you very much for your attention,
> >
> >
> >
> > Alexandre Alves.
>
Hi, thank you very much, your sugestion to change the global
variable $LimitTo4 indeed worked!
The problem was about the g[mu,nu] coefficients of the tensorial
reductions which contain a factor like
1/(D+P-2-M) ,
where D is the space-time dimension. P and M are integers as
defined in equation (4.18) of Denner's Fortschritte der Physik review. If
you keep the default value for $LimitTo4, the limit D -> 4 is taken before
the tensorial reduction, so it's necessary to change $LimitTo4 to False.
Thank you one more time,
Alexandre.
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