HF minutes - 2018/01/04

1)  Bad run determination for Run14 AuAu 200 GeV MTD data - Rongrong Ma

  • Slide 8&9, the split of #RefMult and #gRefMult vs. run may be due to different high/mid/low luminosity trigger setup. The decreasing trend vs. run may be due to increasing luminosity vs. run. Suggest to check if the corrected gRefMult vs. run is flat or not
  • Slide 17, why there is split for nHitsPoss?
    • Suggested to check if larger nHitsPoss corresponding to higher or lower luminosity.
    • One possible explanation is that nHitsPoss correlated with nHitsFit, which is correlated with luminosity.
    • One could also check with embedding.
  • Slide 25, the was question on why there is <\eta> shift in the beginning runs, the answer is may be due to shift of Vz in these runs.

2)  D0 v1 with Au+Au Run14 and Run16 data - Liang He

  • Slide 2, why the #events is less than what other got?
  • Slide 4,
    • Why there is sizable difference of the results from different analyzers.
    • Bottom-right plot, two rapidity bins (|y|<0.4) why Liang's results have much smaller statistical uncertainties, even though his #events is less that the others'.
    • To cross check, suggested the three groups use common set of files and same cuts and compare. Liang will send Email to toher groups to coordinate this check.
  • Slide 9, try bin counting to check the systematic uncertainty.
  • Slide 16, check the systematic uncertainty from fitting. 
    • Also suggested the three groups share the invariant mass distribution to each other, each group fit the distribution from other's the see if the difference is from the invariant mass distribution itself or from the fitting to the invariant mass distribution and the fitting to the angular distribution afterwards.
    • The fitting range starts from 1.6 GeV/c^2, this could be too low to be able to use linear function describe the residual background  

3) Status of run 16 embedding.
    Need to communicate with S&C group to check if the issues can be resolved soon. Otherwise, need to think about Plan B for the QM presentations.