== Installation instructions and pre-workshop exercises ==

 === Install on Windows ===
The different program are foreseen to run on !Linux/Mac. If you don't have Linux or Mac, the best solution is to install Linux (I would advice to install Ubuntu) in dual boot and follow the instructions for Linux.
This video might help you to do so: http://video.google.com/videoplay?docid=-2369893842637434537
virtual machine are fine, but quite often the library readline is not present on the system. This package is not mandatory but allozs mg5 to have history and nice auto-completions.
So you might consider to install that library first and the compile python2.6.


 === Install on Linux ===

  * '''python 2.6/2.7'''[[BR]]
    !MadGraph 5 requires python 2.6 or python 2.7. In order to check your version of python, you can type:
    python --version. Some of the repositories are still on python 2.5. So if updating python via your repository manager didn't work.
    you can download directly python from the following link:
    http://www.python.org/download/
    and follow instructions.
  * '''Madgraph5'''[[BR]]
    You will find madgraph5 package on the following page:  https://launchpad.net/madgraph5.
    For this program, you just need to untar it. 
    To check if mg5 is correctly install you directly try to run it by doing:
    ./bin/mg5
    If you don't have a valid python version. It will fail directly.
  * '''MadAnalysis'''[[BR]]
    This programs is not mandatory but allows to have partonic distributions done automatically.
    In order to install this program, you need to launch mg5 (./bin/mg5) and then type
{{{
   install MadAnalysis
}}} 

 === Install on !MacOs ===

1. '''Basic program'''
  * perl 
  * bash [[BR]]
  Those programs are by default present in any Mac distribution, 
  but just in case you should check that they are all installed in your computer (by doing perl --version). 
  * gmake [[BR]]
  By default, makefile are not recognize on mac. In order to check, you can do 'make --version'. If it says:
  -bash: make: command not found
  then you should install it. The easiest is to install the xcode.
     1. For !MacOs 10.5: https://connect.apple.com/cgi-bin/WebObjects/MemberSite.woa/wa/getSoftware?bundleID=20414
     2. For !MacOs 10.6: http://connect.apple.com/cgi-bin/WebObjects/MemberSite.woa/wa/getSoftware?bundleID=20792
     3. For !MacOs 10.7: http://itunes.apple.com/us/app/xcode/id448457090?mt=12
  In order to be able to download it, you will need to a apple developer account (which is free)
  * gfortran 4.x (To check the version do gfortran do: gfortran --version)
  This program is often not included in standard mac version. In order to download it, you can download it from:
    a.  http://prdownloads.sourceforge.net/hpc/gcc-lion.tar.gz?download for !MacOs 10.7
    b.  http://prdownloads.sourceforge.net/hpc/gcc-snwleo-intel-bin.tar.gz?download for !MacOs 10.6
    c.  http://sourceforge.net/projects/hpc/files/hpc/gcc/gcc-leopard-intel-bin.tar.gz/download for !MacOs 10.5

2. '''!MadGraph5'''
  * '''python'''
    a. The default python version of !MacOs 10.6 is python 2.6 and is (in 99% of the case) fully working with Madgraph5, so nothing to install for you.
    b. The python version of !MacOs 10.7 is python 2.7. And this one works perfectly, so nothing to install for you.
    c. For other version of MacOS, you will need to install python2.7 from the python web site: http://www.python.org/download/
  * '''Madgraph5'''[[BR]]
    You will find madgraph5 package on the following page:  https://launchpad.net/madgraph5.
    For this program, you just need to untar it. 
    To check if mg5 is correctly install you directly try to run it by doing:
    ./bin/mg5
    If you don't have a valid python version. It will fail directly.
  * '''MadAnalysis'''[[BR]]
    This programs is not mandatory but allows to have partonic distributions done automatically.
    In order to install this program, you need to launch mg5 (./bin/mg5) and then type
{{{
   install MadAnalysis
}}} 

 == Instructions for the tutorial exercise ==

   * If you haven't ran the '''tutorial''' before the lectures please do it now.
     Please launch mg5
     ./bin/mg5
     and type the following command:
{{{
   tutorial
}}} 
and follow the tutorial instructions on the screen.

   * The exercice of this tutorial is to 
     1. Use the model generatedby Feynrules
     2. generate $ p p \to U \bar U $
     3. generate some events
     4. pass the events to Pythia
     5. Restart the chain but this time by including all the decay chain in MG5.

   Note that in order to have the correct cross-sections in the second cases or to have the correct branching ratio computed by Pythia in the first case, we need first to compute the width and the branching ratio of the non standard model particles. 
 
   * '''The model'''[[BR]]
     The simple way to have access to a model in MG5 is to put in the directory: MG5_DIR/models
     after that you can simply import it in MG5 by doing 
{{{
   import model MODELNAME
}}} 
     or 
{{{
   import model MODELNAME --modelname
}}} 
     The option --modelname tells MG5 to use the name of the particles defines in the UFO model, and not the usual MG5 conventions for the particles of the SM and the MSSM. In principle this shouldn't change anything in the model that you load.
     The first time that you import a new model, it is a good moment to test it! For this 
     1. You can run MG5 in debug mode (./bin/mg5 --debug)
     2. You can test the Lorentz invariance/Gauge invariance/... of at least a couple of processes. This is one examples:
{{{
   import model MODELNAME
   check p p > a a 
}}}
 
  * '''Generation of events (Decay done in MG5)'''
    Add the decay in MG5 (such that the full spin correlation is taken into-account) and generate events.
    In order to learn the syntax of the decay chain. Please type
{{{
    help generate
}}}

== Playing with the Higgs Characterization model ==

  * '''The model'''
Get familiarised with the model, check the particles available to play the role of a resonance and their interactions.
{{{
   import model HiggsCharact_UFO
   display particles
   display interactions X
}}}

Download the '''UFO model''' for the Higgs characterization here: https://feynrules.irmp.ucl.ac.be/wiki/HiggsCharacterization

 * '''Parton-level event generation'''
1) Try to generate events for different spin/parity options for di-photon final state. What is the diference between 
{{{
   generate p p > X , X > a a
}}}
and
{{{ 
   generate p p > a a
}}}
Check the diagrams.

2) Generate events for a resonance with different parity but same spin (e.g. spin0+, spin0-). Choose parameters properly.

3) Use the matching-scheme within MG5 for p p > x2 + 0,1,2-jets @ 14TeV. Check your DJR plots. Is the matching working properly? 
''For this, you should have MadAnalysis and pythia installed within the MG5 interface.  To instal simply:''
{{{
   install MadAnalysis
   install pythia-pgs
}}}