Simulations for the MOLLER Experiment at Jefferson Lab

Community

Simulations are coordinated on the 12gevmoller_sim@jlab.org mailing list and the JLab 12 GeV Slack workspace (in particular, the #moller_simulation channel). Anyone with a jlab.org email address can join without invitation. Feel free to contact developers there with questions.

Running simulations

There are several options for running simulations:

• downloading and compiling the code,
• using a docker container on any operating system,
• using a singularity container on linux systems.

Simulations can be run in interactive mode when not specifying arguments, or in batch mode when specifying a macro:

Usage:
 remoll [-g geometry] [-m macro] [-u session] [-r seed] [-t nthreads] [macro]

Analyzing the output

You can access the output file with a regular root installation (it will warn about non-perfect support). A listing of the output variables is available for reference.

To take advantage of dedicated functionality for the data types in the output file, you will need to follow the more detailed analysis instructions. To simplify this, you can also use the helper executable reroot which is available wherever remoll is available.

Known issues

Error: LLVM SYMBOLS ARE EXPOSED TO CLING

You may encounter the following error message when running in graphical mode:

 Error in <UnknownClass::InitInterpreter()>: LLVM SYMBOLS ARE EXPOSED TO CLING!
 This will cause problems; please hide them or dlopen() them after the call to
 TROOT::InitInterpreter()!

This is a (generally harmless) known issue. A workaround is to run remoll with OpenGL disabled:

LIBGL_ALWAYS_INDIRECT=1 build/remoll