Hi Robert,
When I run your example with the standard Root and the following
interactive session dynamically linking with the Pythia libraries,
I obtain a correct result, see below.
I use an old version of Pythia (5.7) because I was told that there are
problems with version 6.
Rene Brun
root [0] gSystem.Load("libEG")
(int)0
root [1] gSystem.Load("$PYTHIA/libPythia")
(int)0
root [2] gSystem.Load("libEGPythia")
(int)0
root [3] TPythia pythia;
root [4] pythia.SetMSEL(1);
root [5] pythia.SetPMAS(6,1,175.0);
root [6] pythia.Initialize("FIXT","p","p",820.);
1
******************************************************************************
******************************************************************************
**
**
**
**
** PPP Y Y TTTTT H H III A JJJJ EEEE TTTTT SSS EEEE
TTTTT **
** P P Y Y T H H I A A J E T S E
T **
** PPP Y T HHHHH I AAAAA J EEE T SSS EEE
T **
** P Y T H H I A A J J E T S E
T **
** P Y T H H III A A JJ EEEE T SSS EEEE
T **
**
**
**
**
** *......* Welcome to the Lund Monte
Carlo! **
**
*:::!!:::::::::::* **
** *::::::!!::::::::::::::* This is PYTHIA version
5.707 **
** *::::::::!!::::::::::::::::* Last date of change: 20 Oct
1994 **
**
*:::::::::!!:::::::::::::::::*
**
** *:::::::::!!:::::::::::::::::* This is JETSET version
7.401 **
** *::::::::!!::::::::::::::::*! Last date of change: 11 Feb
1994 **
** *::::::!!::::::::::::::*
!! **
** !! *:::!!:::::::::::*
!! **
** !! !* -><- * !! Main
author: **
** !! !! !! Torbjorn
Sjostrand **
** !! !! !! Theory Division,
CERN, **
** !! !! CH-1211 Geneva
23, **
** !! ep !!
Switzerland **
** !! !! phone +41 - 22 - 767 28
20 **
** !! pp !! E-mail
TORSJO@CERNVM.CERN.CH **
** !! e+e-
!! **
** !! !! Copyright Torbjorn
Sjostrand **
** !! and CERN, Geneva
1993 **
**
**
**
**
** When you cite these programs, priority should always be given to
the **
** latest published
description. **
** Currently this is, for
JETSET **
** T. Sjostrand and M. Bengtsson, Computer Physics Commun. 43 (1987)
367, **
** and for
PYTHIA **
** H.-U. Bengtsson and T. Sjostrand, Computer Physics Commun. 46 (1987)
43. **
** The most recent long description (unpublished)
is: **
** T. Sjostrand, CERN-TH.7112/93
(1993). **
** Also remember that the programs, to a large extent, represent
original **
** physics research. Other publications of special relevance to
your **
** studies may therefore deserve separate
mention. **
**
**
**
**
******************************************************************************
******************************************************************************
Warning: JETSET subversion too old for PYTHIA
1****************** PYINIT: initialization of PYTHIA routines
*****************
==============================================================================
I
I
I PYTHIA will be initialized for p on p fixed
target I
I at 820.000 GeV/c
lab-momentum I
I
I
I corresponding to 39.250 GeV center-of-mass
energy I
I
I
==============================================================================
******** PYMAXI: summary of differential cross-section maximum search
********
==========================================================
I I I
I ISUB Subprocess name I Maximum value I
I I I
==========================================================
I I I
I 95 Low-pT scattering I 2.4146E+01 I
I 96 Semihard QCD 2 -> 2 I 2.7197E+01 I
I I I
==========================================================
********************** PYINIT: initialization completed
**********************
> =================================
>
> The ouput produced is:
>
> ******************************************************************************
> ******************************************************************************
> ** **
> ** **
> ** *......* Welcome to the Lund Monte Carlo! **
> ** *:::!!:::::::::::* **
> ** *::::::!!::::::::::::::* PPP Y Y TTTTT H H III A **
> ** *::::::::!!::::::::::::::::* P P Y Y T H H I A A **
> ** *:::::::::!!:::::::::::::::::* PPP Y T HHHHH I AAAAA **
> ** *:::::::::!!:::::::::::::::::* P Y T H H I A A **
> ** *::::::::!!::::::::::::::::*! P Y T H H III A A **
> ** *::::::!!::::::::::::::* !! **
> ** !! *:::!!:::::::::::* !! This is PYTHIA version 6.115 **
> ** !! !* -><- * !! Last date of change: 27 Jan 1998 **
> ** !! !! !! **
> ** !! !! !! **
> ** !! !! **
> ** !! ep !! Disclaimer: this program comes **
> ** !! !! without any guarantees. Beware **
> ** !! pp !! of errors and use common sense **
> ** !! e+e- !! when interpreting results. **
> ** !! !! **
> ** !! Copyright T. Sjostrand (1997) **
> ** **
> ** An archive of program versions and documentation is found on the web: **
> ** http://www.thep.lu.se/tf2/staff/torbjorn/Pythia.html **
> ** **
> ** When you cite this program, currently the official reference is **
> ** T. Sjostrand, Computer Physics Commun. 82 (1994) 74. **
> ** The supersymmetry extensions are described in **
> ** S. Mrenna, Computer Physics Commun. 101 (1997) 232 **
> ** Also remember that the program, to a large extent, represents original **
> ** physics research. Other publications of special relevance to your **
> ** studies may therefore deserve separate mention. **
> ** **
> ** Main author: Torbjorn Sjostrand; Department of Theoretical Physics 2, **
> ** Lund University, Solvegatan 14A, S-223 62 Lund, Sweden; **
> ** phone: + 46 - 46 - 222 48 16; e-mail: torbjorn@thep.lu.se **
> ** SUSY author: Stephen Mrenna, Argonne National Laboratory, **
> ** 9700 South Cass Avenue, Argonne, IL 60439, USA; **
> ** phone: + 1 - 630 - 252 - 7615; e-mail: mrenna@hep.anl.gov **
> ** **
> ** **
> ******************************************************************************
> ******************************************************************************
> 1****************** PYINIT: initialization of PYTHIA routines *****************
>
> ==============================================================================
> I I
> I PYTHIA will be initialized for p on p fixed target I
> I at -1.997 GeV/c lab-momentum I
> I I
> I corresponding to 2.429 GeV center-of-mass energy I
> I I
> ==============================================================================
> Error: too low CM energy, 2.429 GeV for event generation.
> Execution stopped!
> -------------------------------------------------------------------------------
> -------------------------------------------------------------------------------
>
> I compared with the AtlFast-docu on the root-HP, but didn't find the
> difference up to the initialize-call...
>
> So: what's going wrong?
>
> I'm running root, version 2.20/06 on LINUX.
>
> Any help is welcome...
>
> Thanks, Robert
>
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> + Robert Loke +
> + Humboldt University Berlin +
> + Invalidenstr. 110 +
> + 10115 Berlin +
> + Germany +
> + +
> + e-mail : loke@ifh.de +
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++