Page History

...

• "beam-tri":  simply simulates the beam going though the target; the “tri” refers to trident events that are inserted at the expected rate.  This is intended to be an unbiased representation of our data
• “tritrig-beam-tri”:  the “tritrig” refers to a sample of tridents that are preselected (at the MadGraph level) to be more likely to be in the detector acceptance and pass the trigger cuts so that we can efficiently get a large sample. These then have “beam-tri” overlaid in order to simulate what trident events look like in the detector. 
  
• "wab-beam-tri": beam-tri with wide-angle bremsstrahlung events mixed in.
  
• “ap” and “ap-beam-tri”:  the “ap” stands for “A prime” and is our signal MC…they can be generated at a given mass and ctau, and are produced with and w/o beam overlay (mostly with).  
• pure moller events. Note: beam backgrounds already contain moller events. Pure mollers are intended to be used for specialized studies involving them. Moller and wide angle bremsstrahlung samples
  

Below, each generation step for each sample is outlined. 

...

• beam electrons:  
•  auger xml:  /u/group/hps/production/mc/EngRun2015Scripts/stdhep/beam.xml
•  run with ./runjob.sh stdhep/beam.xml 1pt05 <firstjob> <lastjob>
• the executable that does the event generation is /u/group/hps/production/mc/egs5/beam_v3.exe
• output is an .stdhep file with each event being 1 scattered electron (I think…1 event _may_ be 1 bunch) 
• beam hadrons:  
•  auger xml:  /u/group/hps/production/mc/EngRun2015Scripts/stdhep/hadrons.xml
•  run with ./runjob.sh stdhep/hadrons.xml 1pt05 <firstjob> <lastjob>
• the executable that does the event generation is a GEANT4 release that gets copied locallyorg
• output is an .stdhep file with each event being hadrons from bunch
• unbiased tridents == “tri”:  
•  auger xml:  /u/group/hps/production/mc/EngRun2015Scripts/lhe/tri.xml
•  run with ./runjob.sh lhe/tri.xml 1pt05 <firstjob> <lastjob>
•  this runs MadGraph using the  /u/group/hps/production/mc/trigg/run_card_<ebeam>.dat
• output is an lhe file with each event being 1 trident
• these files are small, so they are bundled 100-to-1 with:
• ./runjob_100to1.sh lhe/tri_merge_100to1.xml 1pt1 1 100
• enhanced tridents == “tritrig”
•  auger xml:  /u/group/hps/production/mc/EngRun2015Scripts/lhe/tritrig.xml
•  run with ./runjob.sh lhe/tritrig.xml 1pt05 <firstjob> <lastjob>
•  this runs MadGraph using the  /u/group/hps/production/mc/tritrig/run_card_<ebeam>.dat
• the cuts here are E(e+e-)>0.8 EBeam and m(e+e-)>10MeV
• output is an lhe file with each event being 1 trident
• signal events ==  “ap-truth”
•  auger xml:  /u/group/hps/production/mc/EngRun2015Scripts/lhe/ap-truth.xml
•  run with ./runjob.sh lhe/ap-truth.xml 1pt05 <firstjob> <lastjob>
•  this runs MadGraph using the  /u/group/hps/production/mc/ap/run_card_<ebeam>.dat
• also converts the lhe to stdhep while adding displaced vertex (though now ct is hardcoded to 0 in the .xml)
• output is an stdhep file with each event being 1 trident

• 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)
  

...

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:

• beam simulation == “beam“(wab-)beam-tri”
•  auger xml:  /u/group/hps/production/mc/EngRun2015Scripts/slic/(wab-)beam-tri_100.xml
•  run with ./runjob_100.sh slic/(wab-)beam-tri_100.xml 1pt05 <firstnum> <lastnum>
•  this submits 100 jobs for each num between <firstnum> and <lastnum>, combining beam, tri, and hadron events into 2ns beam “bunches”, 1 per event
  •  e.g. <firstnum>=11, <lastnum>=20 submits 100 + 100*(20-11) =1000 jobs, since each input # is used to make 100 output files. This example makes files 1001-2000.
  • inputs: 1 .stdhep file each of beam, hadrons, and tri (bundled 100to1) for each num
  • outputs: 100 .slcio files for each num, each sampled differently from the mixed input files
• enhanced tridents == “tritrig”
•  auger xml: /u/group/hps/production/mc/EngRun2015Scripts/slic/tritrig.xml
•  run with ./runjob.sh slic/tritrig.xml 1pt05 <firstnum> <lastnum>
•  runs slic over the tridents, 1 trident-per-event
• signal events == “ap-truth”
  
•  auger xml:  /u/group/hps/production/mc/EngRun2015Scripts/slic/aptruth.xml
•  run with ./runjob.sh slic/aptruth.xml 1pt05 <firstnum> <lastnum>
•  runs slic over signal events, 1 signal event-per-event
  

• 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 even

Readout Simulation

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

...