STAR Flow, Chirality and Vorticity PWG

["Huan Zhong Huang" <huang AT physics.ucla.edu>]

Haojie,

  Instead of taking the ratios of upper and lower, will you please try to have a look at the ratios of the RuRu for runs with <Vx> [-0.05, -0.052] to ZrZr runs with <Vx> [-0.06, -0.062] and compare with what you have now?

  Thanks.

  Huan

 

From: Star-fcv-l <star-fcv-l-bounces AT lists.bnl.gov> On Behalf Of haojiexu via Star-fcv-l
Sent: Tuesday, April 26, 2022 10:20 PM
To: Van Buren, Gene <gene AT bnl.gov>; STAR Flow, Chirality and Vorticity PWG <star-fcv-l AT lists.bnl.gov>
Subject: Re: [Star-fcv-l] STAR presentation by Haojie Xu for Quark Matter 2022 submitted for review

 

Hi Gene, and all,

Thank you for the plot. I also made the same plot with more stat.

 

As I have shown in my previous plots that the multiplicity distribution ratios Ru(<vx> > mean)/Zr(<vx> < mean) (~65 um differences in vx) and Ru(<vx> < mean)/Zr(<vx> > mean) (~9 um differences in vx) are almost the same (see also the attached plot). The result shows no track effeicecy difference at this level.

 

 

 

 

with best regards,

Haojie

On 2022-04-27 11:54, Van Buren, Gene via Star-fcv-l wrote:

Hi, Jamie and all,

On this particular point....

On Apr 26, 2022, at 7:53 PM, James Dunlop via Star-fcv-l
<star-fcv-l AT lists.bnl.gov> wrote:
The beam shifts by ~40 um all the time.  It's beam steering at that
level,
often used to level our luminosity.

I offer the following not as a contradiction, but as complementary
information on the beam positions (and I'm certainly not making any
kind of statement on noticeable impacts from beam positions on track
reconstruction efficiency)...

The mean <Vx> at z=0 for each fill (which I labeled as "x0") is shown
in the below plot obtained from only a small fraction of the event
statistics. The colors show the two beam species. I would conclude
that whatever beam steering they were doing, they managed to get x0
consistent within a given species to within +/-15 microns
fill-to-fill. If it weren't for that consistency, we wouldn't see the
apparent offset between the two species.

But on the core topic of this thread of tracking efficiency
differences between the two species, I do not have the confidence to
say that SpaceCharge & GridLeak distortion corrections are consistent
between the two species at the level necessary to avoid systematic
track reconstruction efficiency differences at the 0.1% level. That
level of confidence would be difficult to achieve, in my opinion.

-Gene
_______________________________________________
Star-fcv-l mailing list
Star-fcv-l AT lists.bnl.gov
https://lists.bnl.gov/mailman/listinfo/star-fcv-l