jewel is hosted by Hepforge, IPPP Durham

Getting started


  • JEWEL needs LHAPDF5 to provide the PDF's. Install LHAPDF following the instructions on the LHAPDF web page and download the PDF sets you want to use. Please note that you will need the fortran version of LHAPDF, that is version 5 (and not the new version 6). In its default setup JEWEL needs the CTEPQ6L1 (number 10042) and EPS09LOR_208 sets. The latter can be downloaded from the EPS09 web page.
  • The provided Makefile assumes that JEWEL will be compiled with gfortran. People who wish to use a different compiler have to modify the Makefile accordingly.


JEWEL relies heavily on PYTHIA 6 for the simulation of matrix elements, initial state parton showers and the hadronisation. It requires a slighlty modified version of PYTHIA 6.4.25, which is distributed together with JEWEL and is not an official release of PYTHIA and may not be used for anything else. Modifications with respect to the official PYTHIA version are (i) an enlarged event record which now has 23000 lines, (ii) a modified LHAPDF interface that can deal with nuclear PDF's and (iii) a customised version of PYEVWT that allows for the generation of weighted events.


  • Download and unpack the tarball. tar xvzf jewel-2.0.0.tar.gz
    cd jewel-2.0.0/
  • Edit the line LHAPDF_PATH := /path/to/lhapdf in the Makefile to point to your LHAPDF installation.
  • Compile the code. make The result of this are two executables: jewel-2.0.0-vac and jewel-2.0.0-simple. The former simulates jet evolution in vacuum (i.e. in e-e+ or pp collisions) while the latter simulates jet evolution in the presence of a medium. In this case the medium is modelled by an ideal gas of quarks and gluons undergoing boost-invariant longitudinal expansion with a transverse profile derved from a Glauber model.

Running JEWEL

The following paths need to be set for JEWEL to run: export LD_LIBRARY_PATH=/path/to/lhapdf/:$LD_LIBRARY_PATH
export LHAPATH=/path/to/lhapdf/share/lhapdf/PDFsets

To run JEWEL with the default setting no parameter file is needed: ./jewel-2.0.0-simple or ./jewel-2.0.0-vac Note, however, that also in the latter case nuclear PDF's will be used.

A parameter file can to be passed to change the setting: ./jewel-2.0.0-simple params.example.dat The file params.example.dat is included in the tarball as an example for a parameter file. The file can contain one parameter per line, the format is <name>␣<value>. Lines starting with a hash are comment lines. For a list of parameters and their default values please refer to the manual.