List of key variables

Tower Variables:  all refer to 2x2 tower cluster identified by params:

par_seedTower=1 GeV ET, detector eta

par_clusterET=4 GeV ET, detector eta

par_tileThresh=0.5 MeV (for tower,pre,post tiles) - used only to count elements but not when energy is summed

1. eta, phi: the energy-weighted center of the tower cluster (in detector space)
2. x,y of the {eta,phi} at Z=SMD
3. seed=hightowerE: energy of highest tower in cluster
   
4. postE: summed energy of all postshower layers behind cluster
   
5. postNum: number of postshowers summed together in postE
   
6. pre1E: same as above for postE
   
7. pre1Num:  ditto
   
8. pre2E: ditto
   
9. pre2Num: ditto
   
10. towerE: ditto, sum 2x2 
    
11. towerNum: ditto
    

 There may be multiple sets of the above variables per event depending how many 2x2 tower clusters are found.

SMD Variables, based on 30-60 strips.  Strips should cover entire  2x2 tower cluster, from corner to corner, plus extra 5 strips on either side  (param below), all other strips in given plane  are ignored

All variables below will have U-plane & V-plane instance, params

par_stripMargin=5

par_stripInCluster=13

par_stripThreshMeV=0.1 (used only for counting strips)

strip section = all  strips  selected based on tower cluster

smd cluster = 13 strips centered on the seed strip (see below)

1. Z coordinate of the plane { or depth 1,2,3}
2. ID of strip @ DC to 2x2 tower cluster center {x,y}
3. {nx,ny} versor perpendicular to strips @ {x,y} in STAR ref frame
4. ID of highest strip
5. ID of the first and last strip in the strip section
6. SMD cluster energy.
7. energy weighted stripID for cluster (it is float)
8. rms of smd cluster in units of strip ID
9. energy in strip section
10. energy weighted stripID for strip section (it is float)
11. rms of strip section in units of strip ID
12. energy summed over ~half of strip section from #6 till the edge with larger ID
13. # of strips in the section with energy > strip thresh

There will be exactly 2 sets of the above variables for every 2x2 tower cluster 

Reconstructed track variables

Use only primary tracks with flag>0 and nFit/Npos>0.51

1. track_eta,track_phi: the reconstructed eta and phi of the track 
   
2. track_p: momentum of that track
   
3. track pt
4. track dedx if avaliable
5. {x,y} coordinate of the cross point of extrapolated outer helix to the SMD disk at Z=Zsmd
6. error of x,y from #5 (if possible, from covariance matrix

Other reco variables, one per event

1. vertex Z poistion & Z error
2. # of prim tracks filtered as above

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Geant information

1. geant_eta,geant_phi & pid : the real thrown location of the particle (from geant track).  
2. geant Z-vertex  (will be 0 for now)
   
   

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Now comes the algo, but not today