GENEPI Monte Carlo event generator.
Describing electroproduction of photons and mesons off free and bound nucleons. Processes described : Bethe-Heitler, deeply virtual Compton scattering, pi0/eta production (and their decay to photons).
Documentation : https://misportal.jlab.org/ul/Physics/Hall-B/clas/viewFile.cfm/2009-024.pdf?documentId=554
Additional features, not in the documentation :
Events are selected with a keep/reject method. This means the output distributions already take into account the cross-sections.
NH3/ND3 targets : events are randomly chosen to be on N or H/D. The output for N has a particle with ID 12. This is a trick, a fake ID to make it go through the simulation without interacting but still be able to recognize N events in the simulation output.
Input file also allows to choose the vertex position and raster radius. The events are distributed uniformely inside an ellipse for which you can choose the center (vx, vy, vz) and x/y radiuses (raster x, raster y).
How to compile (on ifarm, on a clean environment) :
mkdir bin //Create an empty bin directory where the executable will live
source setenv.txt
make
Clean executables :
make clean
Run genepi :
bin/genepi.exe input_file.input
An example of input_file can be found in
input_files/