Les Houches Event File

Here are some example classes for reading and writing Les Houches Event Files according to the proposal by Torbjörn Sjöstrand discussed at the MC4LHC workshop at CERN 2006.

Please note that as of version 3 of HepMC, the LHEF.h file will be a part of that distribution. The version on this site will (hopefully) still be up to date after that, but you should consider simply install HepMC3 and include it as
#include <HepMC/LHEF.h>
You are still allowed to include the LHEF.h file in a distribution of you own program as long as you conform to the included copyright statement.

The classes has now been updated to handle the suggested version 3 of this file standard as discussed at the Les Houches workshop 2013 (The previous suggested version 2.0 was discussed at the Les Houches workshop 2009).

There is a whole set of classes available in a single header file called LHEF.h. The idea is that matrix element or parton shower generators will implement their own wrapper using these classes as containers.

The two classes LHEF::HEPRUP and LHEF::HEPEUP are simple container classes which contain the same information as the Les Houches standard Fortran common blocks with the same names. They also contain the extra information defined in version 3 in the standard. The other two main classes are called LHEF::Reader and LHEF::Writer and are used to read and write Les Houches Event Files

Here are a few examples of how to use the classes: