- Update: Jan. 09, 2020 (Zhanwen's bbcZ)
- Update: Dec. 30, 2019
- Testing various zVtx to implement it in jet study

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1. BBC zVtx: * Detailed explanation by Akio / by Oleg
 a. w/o slewing correction:
  - bbcZ = -0.3 * (bbcTdiff - 4096)
  - bbcTdiff = muDST->event()->triggerData()->bbcTimeDifference();
 b. w/ slewing correction: used Oleg's study and function

2. VPD zVtx:  muDST->btofHeader()->vpdVz();
 * This is the function used to fill the vpdZ in StJetMaker2009's skim file
 * muDST->event()->vpdVz(); : returns only the value '  -1.58819e-23 ', either st_physics or st_fms

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1. Common test conditions:
 a. st_fms_16080002_raw_1500002.MuDst.root
 b. Used all FMS triggers except LED
 c. Ran 50,000 events for efficiency check

2. Results:
 a. Black: BBC w/o slewing correction (42,974/50,000 = 0.8595)
 b. Red: BBC w/ slewing correction (42,616/50,000 = 0.8523)
 c. Blue: VPD (13,264/50,000 = 0.2653)







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3. Zhanwen's bbcZ functions
 a. bbcZ = 633.544 - 0.158 * bbcTdiff (Green)
 b. bbcZ = -0.158 (bbcTdiff - 4000) (Magenta) * NOT 4,096?