HERWIG Information
HERWIG is a Monte Carlo package for simulating Hadron Emission Reactions
With Interfering Gluons, written by Pino Marchesini,
Bryan Webber,
Giovanni Abbiendi, Gennaro Corcella, Ian Knowles,
Stefano Moretti, Kosuke Odagiri,
Peter
Richardson,
Mike Seymour,
and Luca Stanco.
Version 6.510 was released on the 31st of October 2005. The HERWIG source code can be obtained
here.
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:
hep-ph/0011363;
hep-ph/0210213.
The manual is also now available in html.
Furthermore, if you use any supersymmetric processes, please refer
also to:
S. Moretti, K. Odagiri, P. Richardson, M.H. Seymour and
B.R. Webber, JHEP 0204 (2002)
028 [hep-ph/0204123].
A copy of this paper can be obtained here:
hep-ph/0204123.
The classic paper on HERWIG, although by now very out of date, is: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
here.
We are always trying to update our mailing list
of users. If you want to add or delete your name from the list, please
let us know.
Bug tracker
HERWIG now has a
bug tracker,
hosted by the
CEDAR project.
Click on New Ticket to report a bug. By filling in your email
address where requested, you will receive reports on its progress.
Future plans
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 and
only a very small number of new features can be anticipated now, most notably
matrix element corrections for Higgs production in hadron collisions.
HERWIG is being replaced by
HERWIG++,
version 1.0 of which is already available, providing a complete simulation
of e+e- annihilation events. Initial-state parton showers and underlying
events are currently in progress, to enable complete simulation of
hadron-hadron collisions.
HERWIG++ is being built on the framework of
ThePEG and
CLHEP
and is therefore closely linked to
Pythia7, although of course
with completely independent physics implementations.
The authors of HERWIG have made a commitment to all currently running
(and already ceased) experiments, to continue to provide user support
and bug fixes (but not implementation of new features) throughout
their lifetimes.
For future experiments, including the LHC, we plan to provide the same
level of support only until we consider HERWIG++ to be a stable
alternative for Monte Carlo production.
Jimmy
The main new feature of version 6.505 was an improved interface to the
JIMMY generator
for multiple interactions. This is a separate package written by
Jon Butterworth,
Jeff Forshaw,
Mike Seymour
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
here.
ISAWIG
One of the major advances in 6.1 is 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 however. Input files corresponding to the standard parameter sets
used by the LHC experiment can also be obtained from the
ISAWIG
web page.
User feedback
We are always keen to get feedback on HERWIG, particularly about its physics
content. Bug reports will be dealt with most quickly if submitted to the
bug tracker described above, but they can also be sent to the appropriate
authors:
Parton showers: Bryan Webber,
Mike Seymour.
Hadronization: Bryan Webber,
Mike Seymour.
Standard Model processes: Mike
Seymour,
Bryan Webber.
SUSY processes: Kosuke Odagiri (
),
Stefano Moretti,
Peter Richardson.
R-parity violating SUSY processes:
Peter Richardson.
Matrix-element corrections: Mike
Seymour,
Gennaro Corcella.
Other problems: Mike Seymour,
Bryan Webber.
Old HERWIG versions
The last public version of HERWIG was
version 6.4,
released (text or
postscript)
on the 21st of January 2002.
The previous version was
version 6.3,
released
on the 9th of July 2001.
Before that was version 6.2,
released
on the 27th of November 2000.
Before that was version 6.1,
released
on the 17th of December 1999.
Before that was version 5.9,
released
on the 22nd of July 1996.
It is interesting to note that although the time between HERWIG versions
has been slowing, the size of the program
is still growing pretty steadily.
Experimental Tunes
We are trying to maintain a list of the experimental
parameter tunings
of HERWIG. If you want to add to it, please email
Bryan: webber@hep.phy.cam.ac.uk
or Mike: M.Seymour@rl.ac.uk.
Related programs
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:
HERBVI
by Mark Gibbs.
QCDINS
by Mark Gibbs, Andreas Ringwald and Fridger Schrempp.
POMWIG
by Brian Cox and Jeff Forshaw.
Not really related to HERWIG, but the following programs are (friendly)
competitors to it:
PYTHIA
by Torbjörn Sjöstrand
ARIADNE
by Leif Lönnblad
LEPTO
by Gunnar Ingelman, Anders Edin and Johan Rathsman
ISAJET
by Frank Paige and Serban Protopopescu
SUSYGEN
by Stavros Katsanevas et al
Mike Seymour