################################################################################ # # Copyright (c) 2009 The MadGraph5_aMC@NLO Development team and Contributors # # This file is a part of the MadGraph5_aMC@NLO project, an application which # automatically generates Feynman diagrams and matrix elements for arbitrary # high-energy processes in the Standard Model and beyond. # # It is subject to the MadGraph5_aMC@NLO license which should accompany this # distribution. # # For more information, visit madgraph.phys.ucl.ac.be and amcatnlo.web.cern.ch # ################################################################################ tutorial = """ You have entered tutorial mode. This will introduce you to the main syntax options of MadGraph5_aMC@NLO. To learn more about the different options for a command, you can use MG5_aMC>help A_CMD To see a list of all commands, use MG5_aMC>help The goal of this tutorial is to learn how to generate a process and to produce the output for MadEvent. In this part we will learn a) How to generate a process b) How to create output for MadEvent c) How to run the MadEvent output Let's start with the first point, how to generate a process: MG5_aMC>generate p p > t t~ Note that a space is mandatory between the particle names. """ generate = """ You have just generated a new process. Note that the coupling order \"QED=0\" was automatically added by MG5 to avoid non-QCD diagrams which have negligible contribution. You can find more information on supported syntax by using: MG5_aMC>help generate To list all defined processes, type MG5_aMC>display processes If you want to know more about particles and multiparticles present, write MG5_aMC>display particles MG5_aMC>display multiparticles If you want to add a second process, use the add process command: MG5_aMC>add process p p > W+ j, W+ > l+ vl @2 This adds a decay chain process, with the W+ decaying leptonically. At this stage you can export your processes to different formats. In this tutorial, we will explain how to create output for MadEvent. This is done simply by typing: MG5_aMC>output MY_FIRST_MG5_RUN """ display_processes = """ You have seen a list of the already defined processes. At this stage you can export your processes to different formats. In this tutorial, we will explain how to create a valid output for MadEvent. This is done simply by typing: MG5_aMC>output MY_FIRST_MG5_RUN """ add_process = """ You have added a process to your process list. At this stage you can export your processes to different formats. In this tutorial, we will explain how to create output for MadEvent. This is done simply by typing: MG5_aMC>output MY_FIRST_MG5_RUN """ output = """ If you are following the tutorial, a directory MY_FIRST_MG5_RUN has been created which can be used in order to run MadEvent exactly as if it was coming from MG4. Additionally to the MG4 command (see MY_FIRST_MG5_RUN/README), you can also generate your events/compute the cross-section from this interface: Please Enter: MG5_aMC> launch MY_FIRST_MG5_RUN (you can interrupt the computation to continue the tutorial by pressing Ctrl-C) """ open_index = output launch = """This step ends the tutorial of the basic commands of MG5_aMC. You can always use the help to see the options available for different commands. For example, if you want to know all valid output formats, you can enter MG5_aMC>help output In order to close this tutorial please enter MG5_aMC>tutorial stop If you want to exit MG5_aMC please enter MG5_aMC>exit But you can also continue the tutorial to learn some other useful commands: d) How to load a model e) How to define a multi-particle label f) How to store a history of the commands in a session g) How to call shell commands from MG5_aMC h) How to draw the diagrams for your processes without generating MadEvent output To import a model, write: MG5_aMC>import model mssm """ import_model =""" You have successfully imported a model. If you followed the tutorial this is the MSSM. If you want to know more information about this model you can use the following commands: MG5_aMC>display particles MG5_aMC>display interactions MG5_aMC>display multiparticles which show information on the particles and the vertices of the model or presently defined multiparticle labels. Some of the model (including mssm) allow to modify the model (setting some mass to zero, put some matrices diagonal, remove some interaction, ...). You can see the possibility for each model by using the following command: MG5_aMC> customize_model To define a multiparticle label, i.e. a label corresponding to a set of particles, write: MG5_aMC>define v = w+ w- z a This defines the symbol \"v\" to correspond to any EW vector boson. """ import_model_v4 = import_model customize_model =""" The model with your customization is now loaded and you can use it as any other model. Note that if you want to save this specific customization you can do the following: MG5_aMC> customize_model --save=NAME the model will then be accessible by the command (assuming that you are based on mssm) MG5_aMC> import model mssm-NAME To define a multiparticle label, i.e. a label corresponding to a set of particles, write: MG5_aMC>define v = w+ w- z a This defines the symbol \"v\" to correspond to any EW vector boson. """ define = """ You have just defined a multiparticle label. If you followed the tutorial, the label is \"v\" Note that some multiparticles such as as p, j, l+, l- are predefined. Type MG5_aMC>display multiparticles to see their definitions. MG5 allows you to store a file with the list of command that you have used in an interactive session: MG5_aMC>history my_mg5_cmd.dat """ history = """ You have written a history file. If you followed the tutorial this should be ./my_mg5_cmd.dat. In order to load a history file and execute the commands in it, you can do: MG5_aMC>import command my_mg5_cmd.dat or from the shell: ./bin/mg5_aMC my_mg5_cmd.dat It is also possible to display this file directly from MG5_aMC: MG5_aMC>open ./my_mg5_cmd.dat """ open_index = output open = """ Note that in order to open some file, you might be need to use a shell command. Any shell command can be launched by MG5_aMC, by running \"shell\" or starting the line by an exclamation mark (!). The final command of the tutorial is display diagrams. This allows you to draw and look at the diagrams for your processes (in eps format) before creating an output for a given format. This can be useful for a fast check of your process. For this last command, we will also show how combine different command in a single line: MG5_aMC>generate p p > go go; display diagrams Note that when you run output [madevent_v4], the diagrams are automatically written to the matrix.ps files in subprocess directory, just like with MadGraph 4. """ display_diagrams = """ This command was the last step of the tutorial. Quit the tutorial by typing: MG5_aMC>tutorial stop Thanks for using MadGraph5_aMC@NLO. """