Reconstruction, June 16, 2009
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Time: 11:00 EST/10:00 CST
- Ventrilo for sound. (Zisis will connect) See GlueX Communications for detailed instructions
- ESNET Number 8542553
Contents
Reconstruction To Do List
- Generation
- Use genr8 for a2 production
- Skim off (hd_filter) the wanted events by cutting on the total neutral energy (> 6 GeV) but record the total number of events before skimming. The resulting MC data set will be stored for general use.
- Use Pythia for background generation after removing a2 → η π0 from the MC data stream as well as events with total neutral energy <= 6GeV.
- Use a2 charge exchange production xsection vs pythia total xsection to estimate number of signal and noise events
- Analysis
- After pruning the Pythia events, check the generated vs. reconstructed energy in a plot.
- Look at the a2 mass peak - adjust cuts on the eta and pi0 masses then look at the effect on the different angular distributions (i.e. Gottfried-Jackson angles, etc.)
- look at difference between reconstructed and generated z position for less than 65 cm
- look at single photon reconstruction efficiencies
- adjust the error matrix for the BCAL (look in PID/DPhoton_factory.cc)
- Gather all relevant DocDB documents and cross section publications at one spot on the Wiki.
Documents to Review
Tentative Agenda
- Swimming protons
- Discussion on Analysis
swimming particles
- Step 1: use the HDParSim plugin to handle the charged particles (smearing, acceptance, etc.) eg. "fcalTree2 --plugin=hdparsim -PDEFTAG:DParticle=HDParSim -PTHREAD_TIMEOUT=60 -PPRINT_PLUGIN_PATHS=1hdgeant_01.hddm"
- Step 2: HOWTO Project a charged track to a radius or plane I've first swum the particles to the radius of the BCAL. Any protons that fail to do this are then swum to the FCAL plane.
- Step 3: Compare swum positions to DPhoton shower positions.
protons in the BCAL
- There are 5000 thrown events (γp -> ηπ0p -> 4γp) therefore containing 5000 protons with an average of 4-5 showers produced in the GlueX calorimeters (shown below).
- Looking at the difference between the azimuthal angle at the BCAL of the swum proton and the reconstructed showers (DPhoton) there is a definite peak at Δφ = 0. I've taken the swum position and looped over N DPhoton positions and kept the N differences.
- Making a cut on Δφ < 0.1 radian (~5.7 degrees) there are 2860 surviving showers (~57%).
- Looking at the difference between the final proton Z position and the possible DPhoton showers, there is a clear peak around zero (shown in Red below) after making the cut on Δφ < 0.1 radians.
protons in the FCAL
- Taking only the protons that didn't reach the BCAL and swimming them to the FCAL plane, I repeated the same comparison