1) Photonic electrons in Run14 data - Shenghui
slide 2: show S/B and S/sqrt(S+B) for InvMass<0.15 and InvMass<0.1 GeV/c2 for 0.20<pT<0.25 and 0.45<pT<0.5 GeV/c. The InvMass<0.1 GeV/c2 cut certainly shows better result. Whether this conclusion is true for higher pT bins will remain questionable and Shenghui will include similar plots for other pT bins.
Slide 3: there is clearly a difference in the yields between track rotation and like-sign methods, which is also evident in slide 4 and 5. Question is raised on whether the track rotation method can reproduce the combinatorial background in unlike-sign pairs. From slide 5, the answer might be no, as there seems to be significant hadron contamination in unlike-sign pairs which is underestimated by rotational method. In any case, Shenghui will make the plots on slide 3 for different pT bins.
Slide 4-5: the like-sign pairs with "converion radius" at PXL2 are dominated by hadron contamination.
Slide 6: the vertical structure around x=0 in previous study is due to a bug in Shenghui's code. The structure was thought to be a wire attached to beam pipe, which has been ruled out by Bill Christie, and is removed after bug fix.
Slide 8: The study is based on a small fraction of Run14 data, i.e., 1.5M MB+HT events. Shenghui plans to run entire Run14 data sample

Bill Christie:  There is nothing in the region you are asking about (radius less than 8 cm and |z|<10 cm other than the PXL structure itself. The PXL structure is made up of carbon Fiber "D"s, one to the South of the beam pipe and one to the North of the beam pipe. On the edges of these two "D" there is a vertical plane of Carbon fiber that connects the inner D cylinder to the outer D cylinder. Just below the center of the beam pipe, and just above the center of the beam pipe, where these two "D"s (N & S) meet, one thus has two of these vertical carbon fiber planes. That's all I can think of that would give you the locust of vertices you see in this region.

2) Photonic electrons in Run14 data - Xiaozhi
Xiaozhi used analysis trees produced by Bingchu for Run14 Au+Au MB sample. Analysis tree with looser partner cuts will be produced.
Slide 2-6: plotted by mistake distributions for "W HFT like" twice
Slide 6: the x (nSigmadEdx) distribution is discontinous, as evident by spikes and empty lines. This is attributed to the limited resolution introduced by Float->Short convertion of this quantity in picoDST. Bingchu commented that this artificial effect can be removed by shiftting the bin boundaries by 1e-6. Xiaozhi will try it and will use wider bin width to see if this can solve the problem.
Slide 7: there was an extensive discussion on why the yield for Unlike-Like with HFT matching requirement (on primary electron) is close to that without HFT matching requirement. A possible explanation is the pairDCA<0.01cm cut will bias towards tracks with HFT hits. This seems to be consistent with the difference between slide 7 and slide 17. In slide 17, the pairDCA cut is 0.5 cm. However even in slide 17, the difference in the UL-LS yield at PXL1 between with and w/o HFT matching requirements are smaller than expectation based on HFT matching efficiency which is around ~30%. Could this be due to smearing of conversion radius for PXL1 peak in the case of w/o HFT requirement? Will study further in simulation.
Slide 8 and 18: we also discussed why LS overshoots UL in the case of without HFT requirement for InvMass>0.08 GeV/c2 at low primary electron pT. We concluded that it is likely due to different acceptance between LS and UL, which was later confirmed qualitatively by a study did for dielectron analyses. But why this is not the case when HFT is required is unclear. Will need to study further.