This page is intended for posting of the currently existing problems and/or
action items pertaining to the STAR simulation software and is subject to
K.Schweda: request for the ISTB detector geom update
A.Wetzler: ongoing work on the analysis of gamma conversions in the
TPC gas and the inner detector, consultations held
Hal Spinka and Dave Underwood start project on the extra material
description behind the TPC, discussions held
C.Mironov starts a project on a new geometry description for e-RHIC, assistance given
New code submissions from SSD group (Christelle Roy, Lilian Martin), revision, test run.
A comparative analysis of the various XML schemas for the detector description
(in particular AGDD vs GDML) has been accomplished
Yuri Fisyak starts a project to convert the existing STAR geometry into
TGeo cint macros, and then to refactor those manually
Preparation for the VMC workshop at CERN
Sunil Manohar Dogra [firstname.lastname@example.org] joins the VMC geometry project
The VMC workshop at CERN: presented ideas by the STAR computing group
in the area of VMC code restructuring and geometry description
CHEP'04 -- presented the VMC project on behalf of STAR
Online documentation improved
Cu-Cu test run, pending CTB data problem in the chain
Simulation waves completed
Geometry description improved in the area of SSD and the readout cage of the FTPC
First cut of the geometry description for the new tracking detectors (pixel based)
has been done
Valeri Fine: work on Qt and event display
Virtual Monte Carlo evaluation and design work under way.
Tests of the Geant to Root geometry conversion, and tracking comparison have been done.
System of classes has been designed for the VMC implementation at STAR. Rough version
of the TPC geometry coded in TGeo
Job submission via Grid commences
New inner detector (ISTB), work with K.Schweda, in progress
Root workshop takes place in Palo Alto, California. New progress
has been reported in the Virtual Monte Carlo area, and
help from the Root team is enlisted, in order to star developing
the VMC platform for STAR
First test run of VMC is done with "real" STAR TPC geometry,
converted from Geant 3.21 to Root format using the ustility
created by the STAR members.
Transition to the new layout of the simulation software is under way.
The new executable is codenamed "starsim". It's an evolution of the
previously used "staf/gstar", with much better code organization
and versioning, and results in the unified code base between
root4star and starsim.
AuAu200 Hijing run has been completed, and
contains the following datasets, 40k events each:
- Pure Hijing events
- J/Psi decays
- J/Psi decays mixed into underlying Hijing events
- Upsilon decays
- Upsilon decays mixed into underlying Hijing events
- Omega decays
- Omega decays mixed into underlying Hijing events
- Changes have been made to the layout of many detector subsystems in STAR,
including the SVTT, PHMD, BTOF, CALB, ECAL, SISD. Added teh first version of the PIXL
detector and modified PIPE.
The Hijing 1.382 production run is progressing
and we now have roughly a million events produced
Pythia run has been completed with total
statistics of approximately 1.5M events.
The Hijing 1.382 production run is being repeated
due to various problems discovered recently in the
Ntuple based event generator interface, addition
testing thereof, and the fact that a large part of the
previously attempted run was done with a wrong
verison of executable.
More contacts are made with the developers of the CMS
DDD group regarding the possible reuse of their XML based
detector description system.
- Work started on the Technical Requirements Document
for the XML based detector geometry description in STAR.
There are currently about 50k Pythia events produced
waiting evaluation by the members of the various
detector subsystems groups, before we proceed
to a larger run.
We are planning a substantial Pythia 6.203 min-bias run of
approximately 1 to 2 million events. The ballpark value for
the time per event in such simulation is approx. 10 seconds.
This makes for 115 CPU/days for 1 million events, which is
not at all unreasonable.
The pilot project aiming to use the XML geometry description
for the STAR detector has been presented and discussed at the
CHEP'03 conference in San Diego.
- Due to recent code enhancements, the "subprocess id" from the Pythia
event generator, is now propagating through the Monte Carlo and
We have made a transition from the older version of Hijing, 1.33, to the newer one,
1.382. Substantial statistics have been generated with 1.33 for the d-Au run
and these will be still helpful to most analyses done on the detector subsystems.
The main improvement in the newer version is in the updated formula for the deutron
wave functions, which is likely to have effect in most peripheral collision, due to
the different effective size of the deutron.
The "new" Hijing statistics is being generated via production of the actual
events files output by the event generator, as opposed to the "on the fly"
mode of operation used earlier. That would lead to some saving should we
need to rerun the statistics with updated geometry (which is indeed the
case right now).
Based on request from FTPC group and some others, a dedicated "wide Z"
MC run has been done, whereby the size of the diamond (beam corssing)
is considerably larger than the one used in the main simulation runs.
In practice this means the sigma of 80 cm and no hard cuts on Z.
This is based on the observation of the actual diamond size, as reconstructed
from the data, and the need in the FTPC group to study reconstruction
at extreme values of Z.
There have been at least 170,000 events generated under these
conditions, and those have been reportedly reconstructed and successfully
used in the analysis.
Due to the diligence of Joanna Kiryluk and Akio Ogawa, a small defect
was discovered in the geometry layout of the BBC, whereby due the "ONLY"
Geant attribute (set by default) certain hits were lost in this counter.
The correction has been made and the Hijing 1.382 of the statistics will
be run with the corrected version.
Work in progress: based on the study done by Ian Johnson, it has been
confirmed that theere is some material associated with SVT, which is
missing from our Geant model, however detailed. A new comparison of
data and MC provides some guidelines for improving that geometry
The FTPC geometry (the "supogeo.g" file) will need to be updated as the current
version seems obsolete and plain incorrect. That does not have effect on the
quality of the Monte Carlo data due to the small amount of material involved,
as a study has shown.
simple script has been created for mixing "Phase Space" tracks into events produced with event generators
- It has been confirmed that the failure of the Geisha simulation in the current production version of STAF was
due to a faulty build of the STAF earlier this year. The STAF has been rebuilt with gcc version 2.95.2
and is being tested now, with no apparent problems.
- A decision was made to not tie ourself to gcc 2.96 for building STAF/GSTAR simulation software,
partly because this is bound to eventually change anyway, and partly because this version produces
problems with the executable (the infamous infinite loop).
- It is now easier to
run the Pythia
event generator from STAF.
- There has been a bug in the geometry.g file that prevented the flag which activates hadronic shower simulation
GEANT from being propagated in all volumes of the detector. This has been fixed on 12/10/2002.
It necessary, however, to use the following flag in your sim: GCALOR_ON
detp geom year2003 gcalor_on
- GCALOR requires a few data files for it's proper functioning. The files have been
deposited in CVS and reside in the path pams/sim/gphysdata. The GCALOR software, which we
can't modify, was written in such a way that it will look for these files in the directory from which the binary
image was started. Therefore, the files should either be present in the directory where the user
STAF, or have symbolic links in that directory.
gcc version 2.95.2 has been installed locally, but there are some compilation problems (likely
due to wrong standard header files) that need to be resolved.
November 18: Maxim Potekhin joins the STAR collaboration to lead the Monte Carlo