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Overview: 

The following is how 'official' MC production is typically done, by submitting jobs to the JLab batch farm using xml scripts. To run these same steps from a command line with customized jar or steering files, please see 2015 MC Production using a Command Line.

There are 4 steps to MC production:  event generation, detector simulation, readout simulation, and reconstruction. The tools used are: 

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Below, each generation step for each sample is outlined. 

Batch Job Submission:

There is a basic example on the confluence here:

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• ebeam.csh:  given the beam energy string (e.g. “1pt05”) returns the beam energy in MeV
• dz.csh:  given the beam energy string, returns the target thickness
• ne.csh:  given the beam energy string, returns the number of electrons per 2ns bunch
• apmass.csh: given the beam energy string, returns as list of A’ masses to simulate
• mu.csh: only used by lhe generators (e.g. tridents and wab), sets the number of bunches for each component
  

Event Generation: 

The event generation is performed via MadGraph, EGS5, or GEANT4 depending on the type.  Below lists the different type of particles produced, and some instructions on each.

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• moller electrons == "moller":  
•  auger xml:  /u/group/hps/production/mc/EngRun2015Scripts/stdhep/mollers.xml
•  run with ./runjob.sh stdhep/mollers.xml 1pt05 <firstjob> <lastjob>
• the executable that does the event generation is /u/group/hps/production/mc/egs5/moller_v1.exe
• output is an .stdhep file with each event containing a moller pair (93% efficiency) 
• cross section: 0.09 barns, 800k events/s at 50 nA (258 events per 10^8 incident e-)
• cuts: E > 10 MeV, |theta_y| > 10 mrad
  

Detector Simulation

The detector simulation is performed by slic, which is itself a front-end for GEANT4 which helps incorporate the specific geometry HPS uses along with putting the GEANT output into LCIO collections that are then used by the reconstruction in hps-java.  The batch scripts do more than just run slic though; they may also mix components first, such as with the beam overlay. Below is what we do for each sample type:

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• moller events == “moller”
  
•  auger xml:  /u/group/hps/production/mc/EngRun2015Scripts/slic/moller.xml
•  run with ./runjob.sh slic/moller.xml 1pt05 <firstnum> <lastnum>
•  runs slic over moller events, 1 moller pair per event

Readout Simulation

Simulation of the SVT and ECal digital readout is performed using the hps-java framework.

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• moller events == “moller”
  •  auger xml: /u/group/hps/production/mc/EngRun2015Scripts/readout/moller_<trigger>_100to1.xml
  •  run with ./runjob_100to1.sh <auger xml> 1pt05 <firstnum> <lastnum>
  • moller files individually processed by slic are readout in groups of 100to1
    

Reconstruction

Once the readout is obtained, tracks can be reconstructed, creating HPS-Event objects containing pertinent quantities (cluster energy, etc.) that may be analyzed

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