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Herwig++ Versions

The latest release series of Herwig++ is 2.5, first released in February 2011. 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 versions 2.4 and 2.5 are described in our release note [arXiv:1102.1672].

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.

The Herwig++ tarball contains LoopTools by Thomas Hahn.

Herwig++ 2.5.2 release

2011-11-02: Herwig++ 2.5.2 has been released. It requires ThePEG 1.7.2.

If you use LesHoches input with tau spin correlations, you should switch to using ThePEG 1.7.3 instead. Other users don't need to update.

The main improvements are

  • Version 3 of our colour reconnection tunes is now enabled by default. Please note that the pT parameter is energy-dependent and needs to be modified when an LHC run is not at 7 TeV.
  • The jet vetoing model by Schofield and Seymour (arXiv:1103.4811) is available via Evolver:ColourEvolutionMethod, PartnerFinder:PartnerMethod and SplittingFunction:SplittingColourMethod. The default behaviour is unchanged.
  • The initialization process for BSM runs is significantly faster.
  • Decay mode files in the SLHA format can now be read separately in any BSM model with 'set Model:DecayFileName filename'
  • Charged- and neutral-current DIS processes implementing the POWHEG method are now available.

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.

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

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

Herwig++ 2.5.1 release

2011-06-24: Herwig++ 2.5.1 has been released. It requires ThePEG 1.7.1.

The main improvements are

  • Version 2 of our colour reconnection tunes is now enabled by default. Version 1 has been withdrawn.
  • Better handling of unusual SLHA points in SUSY models.
  • Restructured setup of weak current decays.

Herwig++ 2.5.0 release

2011-02-08: Herwig++ 2.5.0 has been released. It requires ThePEG 1.7.0.

The main improvements are

  • new next-to-leading order (NLO) matrix elements, including weak boson pair production
  • a colour reconnection model, with first tunes available on our tune pages
  • diffractive processes
  • additional models of BSM physics
  • new leading-order matrix elements for hadron–hadron, lepton–lepton collisions and photon-initiated processes

Additionally, the MC@NLO program can now generate partonic configurations which can be showered and hadronized using Herwig++ to produce events with next-to-leading-order accuracy in the MC@NLO approach to matching.

Archive

Archived older versions.

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