Here we describe how to make fast detector simulation files using separate external libraries, without installing FastHepSim. Use the Delphes fast detector simulation program to process the MC events. Delphes can read ProMC files directly. First, make sure that ProMC and ROOT library is installed:

echo $PROMC $ROOTSYS

This should point to the installation paths of ProMC and ROOT.

Here are the steps to perform a fast detector simulation using ProMC files from the HepSim repository:

1) Download Delphes-3.2.0.tar.gz (or higher) and compile it as:

wget http://cp3.irmp.ucl.ac.be/downloads/Delphes-3.2.0.tar.gz
tar -zvxf Delphes-3.2.0.tar.gz
cd Delphes-3.2.0
./configure
make

This creates the converter “DelphesProMC” (among others), if “PROMC” environmental variable is detected.

2) For FCC studies, copy and modify the detector configuration file “delphes_card_FCC_basic.tcl”

cp cards/delphes_card_FCC_basic.tcl delphes_card_FCC_notau.tcl

Then remove the line “TauTagging”. Do the same when using the card “cards/delphes_card_ATLAS.tcl” (for ATLAS). We do not use the tau tagging module since it requires complete event records with all mother particles. Since ProMC files are often slimmed by removing some unstable low pT particles and showered partons, Delphes will fail on this line. If you need tau tagging, please use ProMC files with complete particle record.

3) Download Monte Carlo files from the 100 HepSim repository. For example, get a file with 5000 ttbar events generated for a 100 TeV collider:

wget http://mc.hep.anl.gov/asc/hepsim/events/pp/100tev/ttbar_mg5/mg5_ttbar_100tev_001.promc

and then create a ROOT file with reconstructed objects after a fast detector simulation (FCC detector):

./DelphesProMC delphes_card_FCC_notau.tcl  mg5_ttbar_100tev_001.root mg5_ttbar_100tev_001.promc

The conversion typically takes 30 seconds.