[Comphep-common] new CompHEP - 4.5.1

[Alexander Sherstnev]

Deat Beata,

> 1. What is the meaning of using the file symb_batch.pl in the non-GUI mode
> and what is actually the non-GUI mode?
non-GUI means calculation in the batch regime, without launching
CompHEP with the window interface.
If your symbolic calculations are rather light and don't require
several CPUs you don't need the script.
The script has help. Execute:
./symb_batch.pl --help


> 2. It seems I can calculate the e+e- processes in two ways:
> (a) Using Simpson. In that case in the menu "Initial State" I have
>
>    Beam particle 1: parton
>    Beam particle 2: parton
>    Str.Fun1: OFF
>    Str.Fun2: OFF
>
> (b) I can change these items into
>
>    Beam particle 1: electron
>    Beam particle 2: electron
>    Str.Fun1: ISR(100 Beamstr.:540 ...)
>    Str.Fun2: ISR(100 Beamstr.:540 ...)
>
> i.e. the beamstrahlung is ON. But then I loose the Simpson option in the
> menu. My question is what is the difference between (a) and (b) in case of
> e+e- processes. Are both right or one of them is wrong?

the first option is http://en.wikipedia.org/wiki/Adaptive_Simpson's_method
It is applied for 2->2 without PDF. As soon as you switch PDF on, the
Monte-Carlo method (2nd option) is available only.


> 3. I attach a distribution of a e+e- process obtained with Simpson. There
> is a very weird end at the high energies - the curve, or rather the
> straight line, goes very sharply up. I don't know why is it. At this
> occasion I also found that the item "LaTeX" in the menu one gets when
> plotting distributions doesn't work.
The final bin in the plot has no physical meaning. It is a bug. I've
corrected it in our devel version.


Best regards,
Sasha.

-- 
Dr Alexander Sherstnev,
R.Peierls Centre for Theoretical Physics, University of Oxford and
SINP, Moscow State University,
http://www-thphys.physics.ox.ac.uk/people/AlexanderSherstnev