Version 1.2.3 is an update of Sherpa which contains bugfixes and new features.
Version 1.2.3 is an update of Sherpa which contains bugfixes and new features. Please see the Changelog below for a summary of updates.
The Sherpa package can be downloaded here:
A Manual is included in the
Manual/ directory of the tarball. It is
available in the HTML or INFO format and provides extensive
documentation of all parameters. It can also be found online at
A publication describing the physics of the SHERPA Monte-Carlo can be
JHEP02 (2009) 007.
This is meant to be the standard reference, please cite this publication
if you have used SHERPA for your studies. Additionally each run will
create a file called
Sherpa_References.tex which contains information
about the modules used in this run and the corresponding publications
which should be referred.
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 briefly described in the manual.
We also provide a public gallery of results obtained with this version of Sherpa. There you can find comparisons to experimental data and to the previous version of Sherpa, as well as studies of systematics especially with respect to ME+PS merging.
A Changelog for important differences between the previous version and this version is provided below.
If you would like to be kept up-to-date about new versions or important updates of Sherpa, please subscribe to our announcement mailing list.
Patches/known problems/known bugs/FAQs
All known problems/questions and their solutions can be found on our issue tracker (please log in using the given details). If you encounter any problem while installing or running Sherpa, please open a new issue in the tracker.
Bugfix for automatic alpha_s setting, listed under
patch -p0 < model_init_1.patchin the top level directory of your Sherpa installation, and recompile using 'make install'.
Bugfixes for NLO event generation, not currently listed on the
bug tracker. Fix: Apply
patch -p0 < nlo_simulation_1.patchin the top level directory of your Sherpa installation, and recompile using 'make install'.
Bugfix for the Zprime Example Model, listed under
patch -p0 < examplemodel.patchin the top level directory of your Sherpa installation, and recompile the example model in its directory.
Bugfix to properly include radiation from multiple interactions in
the HepEvt? output, listed under
patch -p0 < hepevt_interface.patchin the top level directory of your Sherpa installation, and recompile using 'make install'.
Bugfix to preserve the graviton masses as generated by the MEs
according to the ADD model, please cf.
patch -p0 < add_masses.123.patchin the top level directory of your Sherpa installation, and recompile by using 'make install'.
Bugfixes w.r.t. Version 1.2.2 + patches
Several bugs have been fixed in all parts of the event generation, including the parton shower and ME+PS merging. We strongly recommend upgrading to this newest version where possible.
ME+PS merging for pure QCD multi-jet production
There was a mismatch in the application of the ME+PS phase space slicing between ME and parton shower, which became relevant in the case where many partons were involved in a process, e.g. in pure QCD multi-jet production.
POWHEG and MENLOPS
Weighted event generation according to the POWHEG and MENLOPS approaches is now possible as published in arXiv:1008.5399 and arXiv:1009.1127. Please contact us if you are interested in using this, as it is not fully documented yet. Corresponding example setups are provided.
Tunes for different PDF sets
In addition to the default PDF
cteq66we now also offer an Underlying-Event tuning for the
cteq6l1PDF. Please find the corresponding parameters in the example setup in
Custom particle containers
Sherpa now allows to define custom particle containers, similar to the jets or lepton container. This can be done in the runcard, without altering Sherpa's source code. Please refer to the online manual for details.
A customizable Sherpa -> HEPEVT converter is included as an example, along with instructions for writing a simple interface to external analyses. The converter itself is suitable for use with the H1 framework.
- Final-state level event selector added, for more information cf. ticket 80.
- LHE output