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 a set of datacards and an LHCO file. 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

• param_card.dat: In this datacard it is stored the model, to change it, just replace existing values of particles mass, width, couplings. For instance, in the case of tH analysis, the Higgs boson mass has to be set to 125 and the Higgs-top coupling to -173.
• run_card.dat: Information about colliding particles are stored here, proton-proton collisions are considered. The value of per-beam-energy has to be changed, default is 8 teV per beam.
• Madweight_card.dat: This is the Madweight configuration card. The first thing to change is the name of the job that is going to be submitted. Among the other parameters to set there are the number of events and the parameter of interest. Example: if the mass of the Higgs is the parameter of interests of the specific analysis, then it has to be specified in the following way:

A LHCO file is a text file collecting basic info on all the events of the sample.

• It stores info about the type of particles in the event (muon, electron, jet, met) and relative pt, eta, phi, btag, ect.
• More info about the structure of LHCO files can be found at: http://madgraph.phys.ucl.ac.be/Manual/lhco.html

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:

• http://cmssw.cvs.cern.ch/cgi-bin/cmssw.cgi/CMSSW/GeneratorInterface/LHEInterface/test/testExternalLHEAsciiDumper_cfg.py?revision=1.2&view=markup

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.