- Response to Carl and Zilong's comments in jet meeting at Jan. 8:
   source of minor differences in barrel eta/phu distribution

- A couple of quick QA performed:
  a. Restrict jet reconstruction eta from [-1, 5] -> [-1, 1]
  b. a. + comments out the part "No TPC vertex found"
      (* major change in StJetMaker2015: uses all possible vertex if no TPC vertex is found)

- Results:eta/phi distribution, StJetMaker2012 (left, black or red) vs. StJetMaker2015 (right, blue or magenta)
  * I draw distributions from tree directly - official library was not necessary

- Conclusion: minor discrepancy originated from newly updated part (case for no TPC vertex found).
  Two libraries show exact match for item b.

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   1. eta, item a, 2012 vs. 2015

    2. eta, item b, 2012 vs. 2015

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   3. phi, item a, 2012 vs. 2015

   4. phi, item b, 2012 vs. 2015