# FCC-hh detector studies: Software and detectors

People: A.Kotwal (Fermilab/Duke), L.Gray (Fermilab), S.Chekanov (ANL), J.Strube (PNNL), N.Tran (Fermilab), S-S. Yu (NCU), S.Sen (Duke), J.Repond (ANL)

This wiki describes physics studies for a FCC-hh detector. You can download such samples as discussed in HepSim manual. This wiki is rather generic, but the detector is still evolving. So, please pay attention to the detector we are using for the ongoing studies.

The current FCC-hh detector is sifcch7. It is a compact high-segmented detector based on SiD. You can find this detector in the detector repository. Look for sifcch7.zip file. This detector corresponds to rfull009 tag SLCIO files in HepSim. The description of this detector is here.

The results shown on this page use the Jas4pp data-analysis package. The installation does not have external dependencies besides Java. Make sure Java7 and above is installed. Then run these commands to install the package using Linux/Mac with the “bash” shell:

wget http://atlaswww.hep.anl.gov/asc/jas4pp/download/current.php -O jas4pp.tgz
tar -zvxf jas4pp.tgz
cd jas4pp
source ./setup.sh # takes 5 sec for first-time optimization

The last command optimizes Java packages for the Python language. Now you are ready to run over any file with truth-level and datector-simulation files, such as LCIO and ProMC. This program can be used for:

• Processing ProMC files from HepSim
• Running over SLCIO files with Geant4 simulated / reconstructed events.
• Data analysis (jets, physics vectors, histogram packages)
• Visualisation of reconstructed events using Wired4 display

You can find more details in Jas4pp manual. The example showing how to run over SLCIO files using Jas4pp are located in the “examples/slic” directory of the Jas4pp package.

# LCIO event structure

The standard set of containers is available from the LCIO files posted on HepSim. Read Manual. The API is described in LCIO Java API description.

Look the Java API definition of the needed objects in org.lcsim.lcio. The data containers are shown below:

<hidden>

BeamCalHits
CalorimeterHitRelations
EM_BARREL
EM_ENDCAP
EcalBarrelHits
EcalEndcapHits
HcalBarrelHits
HcalEndcapHits
HelicalTrackHitRelations
HelicalTrackHits
HelicalTrackMCRelations
LumiCalHits
MCParticle
MUON_BARREL
MUON_ENDCAP
MuonBarrelHits
MuonEndcapHits
PandoraPFOCollection
ReconClusters
SiTrackerBarrelHits
SiTrackerEndcapHits
SiTrackerForwardHits
SiVertexBarrelHits
SiVertexEndcapHits
StateAtECal
StateAtEnd
StateAtStart
TKR_RawTrackerHits
TKR_TrackerHits
Tracks
VXD_RawTrackerHits
VXD_TrackerHits

</hidden>

# Using C++/ROOT with LCIO

If you need to read LCIO files in C++ code with ROOT/FastJet, use this example package:

wget http://atlaswww.hep.anl.gov/hepsim/soft/lcio-cpp.tgz -O - | tar -xz;
cd lcio-cpp; make 

It will compile “example.cpp” file linking FastJet package. Look at README file to see how to install the “LCIO” package required by this example. Your LCIO“ files from HepSim should be in the directory “data”.

# Wired Visualization

The current version of the FCC-hh detector is located in the detector repository. Find the zip file with your detector, say “detector.zip” file (“detector” is the actual name of your detector). You can study this geometry using the “description” link.

To visualize this detector, use Wired4. Download the “detector.zip” file, unpack and locate the file “detector.heprep”. Then run it as:

jaspp detector.heprep

Generally, when you open SLCIO file, this detector geometry is copied to the cache directory (in \$HOME/.lcsim).

Alternatively, visualize the detector as [File]-[Open data source]-[HepRep] XML. You will see the detector layout.

Now, we will read the event: Open any *.slcio file you copied from HepSim as [File]-[Open data source]-[LCIO] file. Then click a small button [Go] (top menu bar). It will process events. Then select again [File]-[New]-[Wired 4 view]. You will get an image in the Wired4 display as this:

Now press [Go] again to look at next event.

If you want to see how data records are organized inside the slcio file, do this [File]-[New]-[LCSim Event browser]

To view “slcio” files, Jas4pp automatically downloads the detector geometry from detector repository, therefore, you do not need manual download of heprep files.

# Visualizing geometry using ROOT

(contribution by N.Nikiforou):

You can also visualize the detector using ROOT. Here are a few steps: Locate the file detector.gdml inside detector.zip.

<hidden> This file is created using

slic -g detector.lcdd -G detector.gdml

</hidden>

Once you have the GDML file, you can use ROOT to visualize it. You just need to make sure the ROOT installation has openGL/GDML support (CERN AFS installations have it for sure). At the ROOT prompt do:

TGeoManager::Import("detector.gdml");
gGeoManager->GetTopVolume()->Draw("ogl");

This should popup an OpenGL display with the detector which you can clip, pan, rotate etc. See this image:

# People

This collection of tools for future collider studies was developed at ANL (S.Chekanov, [email protected]) in collaboration with Jan Strube (PNNL) ([email protected]) and Ashutosh Kotwal (Duke U) [email protected] The Java part of the simulator for the linear collider was designed N. Graf, J. McCormick, T.Jonson

Sergei Chekanov 2015/10/08 09:31