Name: Ismail Turan (email_not_shown)
Date: 09/23/05-03:42:53 AM Z


Hi Rolf,

Related to my previous email, I did everything with FeynCalc 4.1.1 just to
be sure that it is not an version issue but almost nothing changed. That's
why, I want to attach a sample calculation that I am trying to do with
FeynCalc(it seems I am not allowed to ettach a file so I should find a way to send the file separately). It is very short and simple calculation. There are three one
loop matrix elements that I included. They are called WSelfoffglnA,
WSelfoffglnA, and WSelfonglnC1. It is a small part of top-c-gluon-gluon
calculation.

Interestingly, the first one is being computed within 20 seconds but the
second one took around 68 minutes. So far I haven't gotten any answer from
the third one. But they are self energy diagrams and very similar to each
other. I have no idea why the second and the third diagram take such a
long time but not the first. Is really the program that slow? If so, I
guess I wouldn't finish my calculation at all. I have around 20 one-loop
diagrams.

Another but minor thing is that even though I defined at the beginning of
the notebook some on shell conditions but the program never takes into
account them. Whenever I get the answer from OneLoop[] and if I use FCE,
then they are implemented. Obviously keeping such terms to the end costs
time.

What should I do to make the calculation effective? Obviously I must be
missing things. This can't be the picture.

If you can take a look to my notebook, I would really appreciate it.

I am using AMD Athlon(comparable with Pentium III), 512RAM.

Thanks a lot in advance,
Ismail

PS: BTW, Is there a way to calculate cross section or decay width or
numeric calculation of PaVe functions A0,B0,C0,D0 with FeynCalc? or is it
only good for calculation the matrix element squared M2(I haven't seen any
documentation beyond M2 calculation).



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