HERWIG is a Fortran Monte Carlo package for simulating Hadron Emission Reactions
With Interfering Gluons, written by Pino Marchesini,
Giovanni Abbiendi, Gennaro Corcella, Ian Knowles,
Stefano Moretti, Kosuke Odagiri,
and Luca Stanco. It should not be confused with the C++ program Herwig++ (see below).
Version 6.521 was released on the 11th of March 2013. The HERWIG source code can be obtained
If you use HERWIG, please refer to it something along the lines of:
HERWIG 6.5, G. Corcella, I.G. Knowles, G. Marchesini, S. Moretti, K.
Odagiri, P. Richardson, M.H. Seymour and B.R. Webber, JHEP 0101 (2001)
010 [hep-ph/0011363]; hep-ph/0210213.
Copies of these papers can be obtained here (postscript format):
The manual is also available (with some minor corrections) in pdf format.
Furthermore, if you use any supersymmetric processes, please refer
S. Moretti, K. Odagiri, P. Richardson, M.H. Seymour and
B.R. Webber, JHEP 0204 (2002)
A copy of this paper can be obtained here:
The classic paper on HERWIG, although by now very out of date, is:
G. Marchesini, B.R. Webber, G. Abbiendi, I.G. Knowles, M.H. Seymour and
L. Stanco, Computer Phys. Commun. 67 (1992) 465.
A copy of this paper can be obtained
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HERWIG has a
hosted by the
Click on New Ticket to report a bug. By filling in your email
address where requested, you will receive reports on its progress.
Version 6.5 has always been foreseen as the final Fortran version of HERWIG.
The recent sub-version releases are tidying up the last few loose ends.
For serious event generation, HERWIG has been replaced by
version 2.4 of which is already available, providing a complete simulation
of most types of collider events. Herwig++ is built on the framework of
HERWIG will continue to be available and maintained at a low level as
long as there is a demand for a Fortran program with its
particular features, such as angular-ordered showering, cluster
hadronization and SUSY spin correlations.
The main new feature of version 6.505 was an improved interface to the
for multiple interactions. This is a separate package written by
and Rod Walker. Jimmy is now a plug-and-play add-on: HERWIG can be run with
or without it without any modifications. It also runs correctly in
'underlying event' mode for any combination of hadron, photon or electron
beam. The code, and further details on how to use it, can be obtained from
Jimmy's home page.
The MC@NLO Package
MC@NLO is a package for combining a Monte Carlo event generator with
Next-to-Leading-Order calculations of rates for QCD processes and is
based on HERWIG. More information can be obtained
One of the major advances in 6.1 was the inclusion of supersymmetry in a
completely general way. This reads in an input file of low-energy parameters
(masses, couplings, decays, etc), which could be written by hand. It is
much easier to generate one with the ISAWIG program, which can be downloaded
together with ISAJET here.
CHARYBDIS2 is a package for simulating mini-black-hole production at
hadron colliders in theories with extra dimensions and TeV-scale
gravity. More information can be obtained
Old HERWIG versions
The last public version of HERWIG was
released (text or
on the 21st of January 2002.
The previous version was
on the 9th of July 2001.
Before that was version 6.2,
on the 27th of November 2000.
Before that was version 6.1,
on the 17th of December 1999.
Before that was version 5.9,
on the 22nd of July 1996.
It is interesting to see how the size of the program
grew over the years of its active development.
In the LEP era we tried to maintain a list of the experimental
parameter tunings of HERWIG.
Several other programs are based on HERWIG. Generally these are written
by third parties and we are not responsible for improving/maintaining/debugging
them. We are however in the process of compiling a list of them for users'
reference. So far we have:
by Mark Gibbs.
by Mark Gibbs, Andreas Ringwald and Fridger Schrempp.
by Brian Cox and Jeff Forshaw.