ATLAS_HH_bbgg

MadGraph5-Pythia8

F llowing tutorial is assume using lxplus account. Since result files of these simulation are large, it is preferred to install the softwares in your CERN EOS storage space.

MG5 installation

cd /eos/user/<initial>/<user name>/
wget https://launchpad.net/mg5amcnlo/3.0/3.5.x/+download/MG5_aMC_v3.5.0.tar.gz
tar xvf MG5_aMC_v3.5.0.tar.gz
export mg5dir=$PWD/MG5_aMC_v3_5_0 

pythia8 and lhapdf6 installation inside MG5

cd $mg5dir 
./bin/mg5_aMC

Then, in MadGraph:

install pythia8
install lhapdf6

During the process, it might ask you whether you want install other packages in support of pythia8, enter "y".

MG simulation

cd $mg5dir
source /cvmfs/sft.cern.ch/lcg/views/LCG_101/x86_64-centos7-gcc11-opt/setup.sh 
export PYTHIA8DATA=$mg5dir/HEPTools/pythia8/share/Pythia8/xmldoc/
export LHAPDF_DATA_PATH=$mg5dir/HEPTools/lhapdf6_py3/bin
./bin/mg5_aMC

Here is a example for generating the signal for diHiggs channel, similar for background or other channel

set auto_convert_model T
import model heft
generate p p > z h, (h > l+ l-), (h > g g)
output sig_zh_14TeV
launch

Then you will see a menu for MG5, type 1 and hit enter to open up the pythia8 for format transformation to .hepmc, then hit enter again to the next step--setting parameters:

set mh 125.0
set wh 0.004
set ebeam1 7000
set ebeam2 7000
set nevents 100000
set iseed 1823211
set etaj 2.5
set etajmin -2.5
set etab 2.5
set etabmin -2.5
set ptj 20
set ptb 20

The process could take about several seconds or several hours depending on the number of events required. After generate the events, don't forget to gunzip the .hepmc.tar.gz for preparation for delphes simulation:

cd <your output directory>/Events/run_01/
gunzip tag_1_pythia8_events.hepmc.gz

Detector simulation on Delphes

Installation of Delphes

git clone git://github.com/delphes/delphes.git Delphes
cd Delphes
export delphes=$PWD

You could also get it from their official website:

wget http://cp3.irmp.ucl.ac.be/downloads/Delphes-3.5.0.tar.gz
tar xvf Delphes-3.5.0.tar.gz 
cd Delphes-3.5.0
export delphes=$PWD

Then compile

cd $delphes
make -j 8

Simulation

./DelphesHepMC2 cards/delphes_card_HLLHC_btag.tcl <name for output root file>.root $mg5dir/<your output directory>/Events/run_01/tag_1_pythia8_events.hepmc