STAR task force for evaluating tracking efficiency uncertainty

[yh66 <yh66 AT rice.edu>]

Dear experts,
     This is Yiding from Rice. Recently I am working on the  
systematic uncertainty of di-electron analysis. I plan to add  
embedding/data mismatching uncertainty specifically referenced in your  
presentation slide available at:  
https://drupal.star.bnl.gov/STAR/system/files/TrkEff.pdf. And I have  
one question about it.
     In Slide 15 of your presentation, you demonstrate the effect of  
different cuts on mismatching. I observed two intriguing aspects in  
this analysis. Firstly, the mismatching appears to be sensitive to the  
DCA cut, which aligns with similar observations made in various  
studies. However, what caught my attention is the substantial  
difference in mismatching between nHitsFit>15 and nHitsFit>20. To the  
best of my knowledge, previous di-electron analyses utilizing Run18  
Au-Au 27GeV data did not report such a significant mismatching  
discrepancy between data and embedded electrons. Could you kindly shed  
some light on the underlying reasons behind this discrepancy?
     I appreciate your great study on the track efficiency  
uncertainty and would be grateful for any insights you can provide to  
help me better understand the question.

BW,
Yiding Han