In order to have MadWeight on the machine just check out it via bazaar (bazaar is installed on our tier 3). This is the development branch, the most up to date.
bzr branch lp:~maddevelopers/madgraph5/madweight_mc_perm
Once MadWeight is on the working machine, the first step is to calculate the matrix elements for the process to consider: the hypothesis HP. It is possible to it by launching MadGraph and defining the hypothesis process.
cd madweight_mc_perm ./bin/mdg5 # launching MadGraph generate p p > t h b~ j $$ w+ w-, h > b b~ , t > b l+ vl # generating the process add process p p > t~ h b j $$ w+ w-, h > b b~ , t~ > b~ l- vl~ # adding the complementary channel output madweight tHbb_HP # saving the output in the tHbb folder (tHbb_HP folder will be automatically created)
Madweight requires as input an LHCO file and a set of datacards.
A LHCO file is a text file collecting basic info on all the events of the sample.
LHE to LHCO: lhco files can be converted from LHE files. To do this a script is available from MadGraph website. Download it in the working directory:
wget https://cp3.irmp.ucl.ac.be/projects/madgraph/raw-attachment/wiki/MadWeightTool/lhe2lhco.py.txt mv lhe2lhco.py.txt lhe2lhco.py
EDM LHE to LHCO: lhco files can converted also from EDM LHE files using a standard tool provided within the CMS framework (ExternalLHEAsciiDumper). Copy it and change the name of the input file:
ROOT to LHCO: To convert root files to LHCO files a standard tool does not exist, because it depends on the structure of the user root file. A root/lhco converter script to convert tH analysis root ntuples in lhco file is going to be implemented and it will be posted here as soon as it will be ready.
Datacards are stored in the sundirectory Cards of the created folder tHbb_HP. The datacards to customize are three: param_card.dat, run_card.dat and Madweight_card.dat
11 mass # The parameter of interest 12 25 # Id of the particle for wich the parameter must be changed 13 115 # Different values of the parameter for which a scan will be performed 13 125 13 130
In order to apply the matrix element method to a sample S under the hypothesis HP, Madweight has to be run using the LHCO file relative to the sample S and the datacards related to the hypothesis HP.
cd tHbb_HP cp $MYSAMPLE_PATH/MySample.lhco Events/input.lhco
./bin/mw_options define_transfer_fct Please choose your transfer_function between 0 / dbl_gauss_pt_jet 1 / uniform 2 / jet_gaussian 3 / user 4 / single_gaussian 5 / gauss_on_leptons 6 / all_delta [dbl_gauss_pt_jet, uniform, jet_gaussian, user, single_gaussian, gauss_on_leptons, all_delta, 0, 1, ... ][60s to answer]
At this point MadWeight propose to check the datacards, change again transfer function if desired or specify another lhco file. If everything has been already set properly before, then just type 0 to go ahead.
In order to apply the MEM over different samples, but under the same hypothesis, follow the next steps:
namein Madweight_card.dat has to be changed. A new subdirectory name will be created in the Events folder each time MW is run. Results will be stored there. It is very important to change this value because otherwise the previous results will be overwritten.
Results will be collecting in the file weights.out in the Events/name/ folder.