This repository holds the code for producing a SLHA file from an UFO input model.

The following external codes are required:

• MadGraph

The script installer.sh will try to fetch the appropriate tarballs and install them. A few patches will be automatically applied to the MadGraph installation in order to allow for the automatized computation of cross-sections. Therefore we do not recommend to use an external MadGraph installation. The patched files can be found in madgraphFixes.

A SLHA file for any input model and set of parameters can be obtained running:

./createSLHA.py -p <parameter file>

The parameter file specificies several options for computing the cross-sections and the decays. An example with comments can be found in slha_parameters.ini. Note that generating SLHA files for several model parameters can be automatically done by defining the corresponding parameters using the $loop{} syntax. Also, dependence between the parameters are easily implemented using the parameter variable syntax ${option} to reference options in the same section or ${section:option} to reference options in a different section (see comments in slha_parameters.ini and a more complex example in lhiggs_parameters.ini).

Note that the automatic computation of cross-sections for all possible cross-section channels may demand a lot of CPU time. Therefore we recommend the user to judisciously choose which particles to compute cross-sections for and, if needed, explicitly specify the required processes through the use of the process card (see comments in slha_parameters.ini).

The creation of an SLHA file from the UFO input is done according to the following steps:

1. If a process card is defined and it already exists (see proccard in slha_parameters.ini), this file will be used to generate the madgraph processes. Otherwise a process card will be autmatically created to generate all p p -> 2 processes using the particles listed in computeXsecsFor. The output will be saved to the process folder (defined by processFolder in slha_parameters.ini). If the process folder already exists, the process generation will be skipped.
2. Once the information about the processes are stored in the process folder (see above), this folder will be copied to the madgraph output folder (see mg5out in slha_parameters.ini). When creating several SLHA files in parallel, it is important to assign one distinct mg5out folder for each SLHA file (if cleanOutFolders = True, these folders will be automatically removed at the end of the run).
3. Events will then be generated using the parameters set by the "MadGraphSet" section in slha_parameters.ini and the run and parameter cards defined by the runcard and paramcard options. If these are not defined or the files do not exist, the default files will be used.
4. Finally the LHE event file generated by madgraph (specified as the ''inputFile'' option in the ''slhaCreator'' section in slha_parameters.ini) will be read and used to extract the cross-sections and the other SLHA blocks, which will then be written to the output SLHA file (defined by the ''slhaout'' option in the "slhaCreator" section in slha_parameters.ini)
5. If cleanOutFolders = True, the madgraph output folder(s) will be deleted.