Splitting mass in small cells - opening angle

- Update: Akio's study in RUN15 www.star.bnl.gov/protected/spin/akio/fms2015/showershape.html

- Continue study about splitting behavior of mass in small cells
- Tested mass vs. openA for following conditions:
   a. in separated zgg, stepwidth of 0.1 (ex. mass vs. openA, for 0.1 < zgg < 0.2)
   b. in separated pair (pi0 candidate) energy, stepwidth of 10 (ex. 20 < pair E < 30 GeV)

- Very strong opening angle dependence observed in small cells. The splitting problem originated from this
- Checked distance between each points as well: each peak corresponds to cell distance (4, 8, 12, ..., in cm)

- In my opinion this problem is originated from FMS cluster finder or point reconstruction
- Judging from XY distribution of reco. points ( https://drupal.star.bnl.gov/STAR/system/files/CKim_FMSCalib_190325.pdf , from p8 ),
   reconstructed points tend to much concentrated near the center of the cell
- Can this behavior related to 'cutoff energy' in the determination of cluster's sigmaMax process?

//---------------------------------------------------------------------------------------------------------

 - detId = 10


  a. mass vs. openA, by separated zgg



  b. mass vs. openA, by separated zgg, proejction to X



  c. distance between two reco. points ( sqrt( dX^2 + dY^2 ) )



 d. mass vs. openA, by separated pair E



//---------------------------------------------------------------------------------------------------------

 - detId = 8


  a. mass vs. openA, by separated zgg



  b. mass vs. openA, by separated zgg, proejction to X



  c. distance between two reco. points ( sqrt( dX^2 + dY^2 ) )



  d. mass vs. openA, by separated pair E