herwig is hosted by Hepforge, IPPP Durham

Herwig++ Versions

The latest release series of Herwig++ is 2.7, first released in October 2013. To receive email updates about new releases, please send a blank message to herwig-announce-join@projects.hepforge.org.

The detailed Herwig++ reference manual containing many examples is available at arXiv:0803.0883.

The new features that were introduced in version 2.7 are described in our release note arXiv:1310.6877.

Another useful reference with much information on the physics background of Herwig++ is the MCnet review paper on Monte Carlo event generators, arXiv:1101.2599.

Examples of the results of Herwig++ 2.6 compared to LEP, Tevatron jet, Tevatron W/Z, Tevatron photon production, Star, LHC jet, LHC W/Z, LHC photon production, HERA, CERN SppS and ISR and B-factory data made using Rivet are also available.

The Herwig++ tarball contains an adapted copy of LoopTools 2.6 by Thomas Hahn.

Herwig++ 2.7.1 release

2014-07-07: Herwig++ 2.7.1 has been released. It requires ThePEG 1.9.2.

The main improvements are:

  • New shower switches to select schemes for momentum reconstruction (see NEWS file)
  • Improved efficiency to gain a 10–20% speedup in LHC events.
  • ThePEG now supports LHAPDFv6 directly.

As usual, the 'NEWS' files in both source tarballs contain a detailed list of changes. Any questions or comments should be directed to herwig@projects.hepforge.org.

To help with our future transition to C++-11, we provide the --enable-stdcxx11 configure flag. Please try to run test builds with this flag enabled in ThePEG and Herwig++ and let us know about any problems and successes, but do not use this in production code yet. This flag is intended to become the default in one of the next major releases.

Please respect the MCnet guidelines for Event Generator authors and users.

Contact herwig@projects.hepforge.org with comments or questions.

Herwig++ 2.7.0 release

2013-10-28: Herwig++ 2.7.0 has been released. It requires ThePEG 1.9.1.

The main improvements are

  • A converter for BSM model Feynman rules in the UFO format, allowing Herwig++ to run most BSM models without having to hand-code vertices.
  • Scaling parameters to estimate shower uncertainties.
  • More flexible and consistent rewrite of Matchbox NLO matching.
  • Generic BLHA2 interface to one-loop amplitude codes.
  • New underlying event tune UE-EE-5-MRST.
  • Many improvements in BSM code, including 4-body decays.


Archived older versions.

For more up-to-date information and user guides, see the ThePEG/Herwig++ Wiki.