Star-tpc-l mailing list

["Van Buren, Gene" <gene AT bnl.gov>]

Hi, TPC-ers

This evening I took advantage of the calibration production of the 19.6 GeV 
AuAu 2019 data with the new TPC alignment to look at h-/h+ ratios. I also 
looked at h-/h+ for this same dataset back in 2021 using the P21ia 
calibration production with an older version of TPC alignment, allowing for a 
direct comparison of whether the new alignment improves the sector-to-sector 
variations that have been seen in past TPC alignment versions. Unfortunately, 
while this analysis shows that the new alignment has changed most sectors' 
distortion of h-/h+, its sector-to-sector variations remain at a similar 
scale.

https://drupal.star.bnl.gov/STAR/blog/genevb/h-h-Run-19-196-GeV-new-TPC-alignment

Caveat: since the h-/h+ ratios I show are normalized to the integrated ratio, 
this analysis does not demonstrate whether the new alignment improves (or 
not) any overall biases (it may in fact do that). It is useful only in the 
sense of looking at variation between the sectors.

Thanks,
-Gene