RUN15 pptrans calibration final QA (1)

- Conditions applied for conventional integrated mass distributions I've been shown:

 a. For each event:
     a-1. Skip abort gap
     a-2. Skip if FMS_LED trigger is fired
     a-3. Skip the event which has no BBC zVtx info, if use_zVtx is on (default is on)

 b. For each pi0:
     b-1. 20 < pairE (GeV) < 40
     b-2. Mass < 0.5 0GeV)
     b-3. Zgg < 0.7
     b-4. Require each cluster has only 1 point (single point clusters)
     b-5. Cluster quality cut for small cells to suppress skewed cells
     b-6. Assign the pi0 for the cell which satisfy energy cut (hitE / pairE > 0.3) - this is almost equivalent to selecting leading energy cell

 c. After collecting pi0 mass vs. ch for each detId, I projected it to Y (mass) axis


- To do more stringent check, prepared a QA maker shares most part with StFmsCalibMaker
- Then Collected pi0 by following conditions:

 d. For each event: same to a.

 e. For each pi0:
     e-1. Search the pi0's detid and top/down location by using its leading energy hit position
     e-2. Then save pi0 mass vs. pairE for each of following condition:
             e-2-QA0. zgg < 0.7
             e-2-QA1. zgg < 0.7 + zVtx
             e-2-QA2. zgg < 0.7 + zVtx + # of points per cluster = 1 (for both clusters)
             e-2-QA3. zgg < 0.7 + zVtx + # of points per cluster ≠ 1 (for at least a cluster - ELSE condition to e-2-QA2)
             e-2-QA4. zgg < 0.7 + zVtx + cluster quality cut
             e-2-QA5. zgg < 0.7 + zVtx + # of points per cluster = 1 (for both clusters) + cluster quality cut (closest to calibration condition)

     e-3. 1st QA results for day 80-81, with minimum cut (zgg + zVtx). At first glance it looks meaningless to check pairE < 20. Too many backgrounds

     e-3-A. min pair E >  0 (no cut)

     e-3-B. min pair E >  10

     e-3-C. min pair E >  20

     e-4. Quick check for the effect of # of points per cluster requirements

     e-4-A. min pair E >  20  + # of points per cluster = 1

     e-4-B. min pair E >  20  + # of points per cluster ≠ 1

     e-5. Plan to continue with pairE > 20 cut. Get these plots for all days in pptrans
     e-6. Preparing comparison to conventional PSU calibration results, by using gainCorr in DB w/o bad/dead correction