Sherpa 2.2.8

Version 2.2.8 is a bugfix release in the Cho Oyu series and we encourage all users to update to this version.

If you spot any problem, please send us an email. If you would like to be informed about newer releases, please subscribe to our announcement mailing list.


The Sherpa package can be downloaded here: SHERPA-MC-2.2.8.tar.gz

In can also be accessed via git using

  • the web interface
  • or git clone -b rel-2-2-8 for a local clone.

A Manual is included in the Manual/ directory of the tarball (or the git-clone). It is available in the HTML and INFO format and provides extensive documentation of all parameters. It can also be found online.


The main reference for Sherpa 2.2.x is arXiv:1905.09127. Please cite this publication if you have used Sherpa 2.2.x for your studies. Additionally, each run will produce a file called Sherpa_References.tex which contains information about the modules used in this run and the corresponding publications which should be referred. If in doubt, please seek the advice of the Sherpa authors.


You can find a large collection of example setups for using SHERPA in various different colliders/processes in the Examples/ directory of the tarball. They are also described in the manual.



  • Phase space biasing with Enhance_Observable re-enabled for unweighted events (!193, !209)
  • Significant reduction of negative weight fraction possible with NLO_CSS_PSMODE=1 option for leading-colour S-event showering (!200)
  • Improve safeguarding against large Sudakov reweighting factors (!212)
  • HepMC 3.1 interface added (!196)
  • Rivet 3.x interface added (!192)
  • Make OpenLoops library finding more robust, e.g. for LCG OpenLoops installation (!215)

Bugfixes (runtime issues)

  • Crash when soft spin correlations and neutral meson mixing were enabled (#53) -- thanks for the report from ATLAS
  • Widths updated in hard decay handler not used by ME generators (#182)

Bugfixes (compilation issues)

  • None

Known issues

  • Note that dijet production with additional jets merged with the CKKW algorithm is broken in the 2.2.x series (#46)
  • Also see our issue tracker