Name: Frederik Orellana Date: 11/03/02-01:56:12 PM Z


Hi!

Sorry for the late reply. And thanks for testing.

There are two issues:

1) The syntax accepted by OneLoop (try ?OneLoop): OneLoop[q, amplitude],
where q is a raw symbol and amplitude is an amplitude. You’re giving a list
of amplitudes (admittedly a rather short one) as second argument. I usually
do OneLoop[q,#]& /@ {amplitude1, ….}. We could of course make OneLoop
smarter and accept more diverse input - I don’t know…

2) The FeynArts model files, which, as mentioned, I have not really used:
My patch script FAPatch.m replaces Global`PolarizationVector with
Global`FAPolarizationVector. The reason for doing this is that FeynCalc
already uses the symbol PolarizationVector, but has it in a different
context than Global` and uses a different input syntax. Unfortunately, I
didn’t notice that in the model files, the symbol PolarizationVector is
written as, well, PolarizationVector, not Global`PolarizationVector,
because the context is already Global`. So my patch misses them. I will, of
course, correct this.

So, to quickly fix it, replace PolarizationVector with FAPolarizationVector
in the files
Lorentz.gen, Lorentzbgf.gen and QED.gen.

Hope this helps.

Frederik

At 17:51 24-10-2002 +0100, you wrote:
>Hi!
>I have hit a problem using OneLoop. Have attached a notebook which
>illustrates it. It is very simple and I am hoping that I have made a stupid
>mistake - being a beginner to all this! Hope someone can put me right.
>Thanks
>Jeff F
>
>=====================================
>Department of Physics & Astronomy
>University of Manchester
>Manchester M13 9PL
> UK
>Tel: +44 (0)161 275 4220; Fax: +44(0)161 275 4218
>http://theory.ph.man.ac.uk/~forshaw/
>