Sherpa 2.2.11

Version 2.2.11 contains bug fixes for several crashes, 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.

Download

The Sherpa package can be downloaded here: SHERPA-MC-2.2.11.tar.gz

In can also be accessed via git in the web interface:

  • v2.2.11 as tag matching the release tarball
  • rel-2-2-11 as maintenance branch including potential further patches

or cloned into a local working copy:

  • git clone -b rel-2-2-11 https://gitlab.com/sherpa-team/sherpa.git

A Manual can be found online and in the Manual/ directory of the source. It is available in the HTML and INFO format and provides extensive documentation of all parameters.

Changelog

Enhancements and new physics features

  • Improvements in ME+PS merging for unordered scale configurations (!381)
  • New NLO_SUBTRACTION_SCHEME option for improved behavior of the parton shower in processes with large higher-order contributions from t-channel gluon exchange (!382)
  • Additional power corrections to better match soft limit (!394)
  • Implement csin2_thetaW for SMEFTsim (!319)
  • Exponentiation version of EWvirt corrections (!348)
  • Phase space enhancing with function for unweighted event generation (Enhance_Function) (!357) (!379)
  • Rivet interface improvements: zipped YODA files (!374) and split pos/neg weights (!376)

Runtime issues

  • Bugfix in Comix for models with vertices with negative coupling orders (!327)
  • Bugfixes for crashes with new SPECIAL_TAU_SPIN_CORRELATIONS option (!335) (!362)
  • Bugfix for crash with spin correlations in ttll setups (!388)
  • Bugfixes for non-standard KFACTOR treatments (!352)

Compilation issues

  • Fix build problem with very new glibc (!328)
  • Updated swig requirement for python interface to 2.0.12 (!342)
  • Improvements in HepMC3 linking (!380)
  • MCFM interface fixes (!389)

Known issues

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

References

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.

Examples

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.