STAR Flow, Chirality and Vorticity PWG

[Sergei Voloshin <voloshin AT wayne.edu>]

Hi Shinichi,

Thank you for email.

You are right... see more comments below,

regards,

Sergei

On Wed, Oct 27, 2021 at 9:35 PM ShinIchi Esumi via Star-fcv-l <star-fcv-l AT lists.bnl.gov> wrote:

Dear Sergei

Thanks for the interesting results. I just like to make sure your “r” and “l” are 

zdc Psi1 planes without flipping the angle between the forward and backward, 

therefore the raw signal from “l” is only reversed, while “r” and “r-l” are expected 

to be the same for the first page on the global signal, right?

yes 

For the local signal, 

“tr” and “tl” are same to start with, so I was wondering you could even improve the 

TPC resolution (full TPC E.P.) without making eta-subevent, but just by excluding 

the pair of daughter tracks from the full TPC Q-vector for each lambda, only if 

they are part of the Q-vector.

correct 

With this you could gain in statistics, that we do not 

need to exclude lambda decaying daughters going to forward and backward, in 

addition to the E.P. resolution improvement, that is also effective gain in statistics. 

Have you considered?

Yes,  I am still checking if any biases left ... The improvement in statistics is not "two-folded" though, the subevents are weakly correlated and correlating lambda with two half-events is similar to correlation to one "full" event

We could do this pair-by-pair, or by making many small 

eta slices to exclude this auto correlation (as you taught me long time ago:), 

although we always need to think about primary and global track relation and/or 

correspondence. Your current methods would be more safe and robust, so we 

might like to choose for the final results anyway, but I just thought about the most 

aggressive way to improve statistics by seeing your word “requiring both daughters 

to be opposite side of TPC (w.r.t. 2-sub E.P.)”.

I agree. statistics wise the results for local polarization can be somewhat improved.  In progress.  

Anyway thanks a lot for the nice 

result. Maybe you have other new directions to go? 

We are checking with Takafumi some new things, but even what is already tested -- e.g. Pz vs third harmonics  is worth of speedy publication.

I will try to update the presentation with more results (pt dependence, EPs from other detectors. = more "technical" - hyperon pt distribution, v2 etc. Just need to plot those...)

 

Best regards, ShinIchi 

On Oct 28, 2021, at 9:30, Sergei Voloshin via Star-fcv-l <star-fcv-l AT lists.bnl.gov> wrote:

Dear all,

I have some results on hyperon polarization in isobar collisions, but

I was not able to join the meeting today, and I will not be able to do it next week.

I decided to put a short presentation at the protected area:

https://www.star.bnl.gov/protected/bulkcorr/voloshin/isobars/isobarPolarization2.pdf

My results should be considered as an independent cross-check of the results presented by Takafumi (no significant differences observed so far).

All the hyperon selection cuts are the same as used in Takafumi's analysis.

Any comments are very welcome.

Best regards,

Sergei

--

======================================
 Sergei A. Voloshin
 Professor of Physics,  Wayne State University,
 666 W. Hancock,  Detroit,  Michigan,  48201
 e-mail: sergei.voloshin AT wayne.edu
 Phone: 1-313-577-1630;  Fax: 1-313-577-0711     
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======================================
 Sergei A. Voloshin
 Professor of Physics,  Wayne State University,
 666 W. Hancock,  Detroit,  Michigan,  48201
 e-mail: sergei.voloshin AT wayne.edu
 Phone: 1-313-577-1630;  Fax: 1-313-577-0711     
======================================