MadGraph5_aMC@NLO

http://madgraph.phys.ucl.ac.be/
http://amcatnlo.cern.ch/

Information on the process to be generated is found in the file
index.html in this directory, which should be viewed using your web
browser.

The executables you need to run are contained in the bin/ directory

The bin/aMCatNLO executable open an interactive shell, from which you
can exec different commands (some of which are also covered by the
other executables)

Shower settings
---------------
During the shower phase some parameters are not arbitrary as they have
to be identical to those we have assumed in the Monte Carlo subtraction
terms.
In particular, the following settings MUST NOT BE CHANGED:

HERWIG6:   SOFTME = .FALSE., HARDME = .FALSE., PTMIN = 0.5D0
HERWIGPP:  ReconstructionOption=General, InitialInitialBoostOption=LongTransBoost
PYTHIA6Q:  MSTJ(43) = 3, MSTJ(47) = 0, MSTJ(48) = 0, MSTJ(50) = 2,
           MSTP(67) = 2, MSTP(68) = 0, PARP(67) = 1D0, PARP(71) = 1D0.
PYTHIA6PT: MSTP(67) = 2, MSTP(68) = 0, PARP(67) = 1D0.


generate_events
-------------------

Run event generation at NLO, using the MC@NLO prescription for the
generation of unweighted events that can be passed to a parton-shower.
Event genration is done in three steps: in the first step, the grid
for the integration is set. In the second step, while computing the
cross-section, the envelope for the unweighting is computed.  Finally,
in the third step, events are generated.  If no extra options are
given, the (parton-level) .lhe file is passed to the parton-shower
MonteCarlo, generating a file either in StdHEP (for Herwig6 and
Pythia6) or in HEPMC format (for Herwig++).  The parton shower
MonteCarlo and the desired number of events have to be specified in
the run_card.dat (You will be prompted to edit it just after typing
the command). Note that, because of the way MC@NLO generates events,
any event sample can be showered only with the parton shower it has
been generated for. Otherwise you will obtain unphisical/wrong
results. For the same reason, also plots obtained using the
parton-level events in the .lhe file (without showering them) are
unphysical.
If you want to first generate a smaller sample of events, and then a
larger one with the same cuts/parameters, you can skip the
grid-setting/ integration phases in the second run (which may be time
consuming).  To do this, when running for the second time, just use
the -o/--only-generation option (possibly also -n/--nocompile)

shower RUN
Generate showered events in StdHEP/HEPMC format (see above), for the
parton-level .lhe event file contained corresponding to run RUN (the
event file is Events/RUN/events.lhe.gz).  All informations
(parton-shower to be used, number of events contained in the file,
etc...) are directly read from the file header. 

calculate_crossx
Calculate the cross section and distributions at fixed order.