STAR Correlations and Fluctuations PWG

["樊碧君" <bjfan AT mails.ccnu.edu.cn>]

Dear ShinIchi,

Thank you very much for your thoughtful comments.

The formula I used for calculating phi* is following,

phi* = phi + asin(sign*0.15*0.5*R/pT). 

As the statistics(we used the full statistics) of K+ in FXT energies is too low, it is difficult to see the dependence of different R. What's more, the statistics of forward rapidity is lower than mid-rapidity, it's more difficult to see that. The following 2D plot shows nHitsfit vs. eta after PID and track cuts.

As for the weight in CRAB, the "raw" I mentioned last email refers to "un-smeared". Sure, when we fill the qinv histograms for smeared correlation function, I use the smeared qinv to do that. But I couldn't understand what you said "You would also need to do this correction in an iterative way, since you do not know the final results to start with…" Could you please kindly tell me what's the "iterative way" means?

About the last suggestion you mentioned, due to the limited statistics of kaon, at FXT energies, it might be tough, but I'd like to do that in different pT regions in my 7.7 GeV analysis, as at this energy, there are more statistics.

Thanks and regards,

Bijun

------------------ Original ------------------

From:  "EsumiShinIchi"<esumi.shinichi.gn AT u.tsukuba.ac.jp>;

Date:  Wed, May 31, 2023 10:08 AM

To:  "star-cf-l"<star-cf-l AT lists.bnl.gov>;

Cc:  "樊碧君"<bjfan AT mails.ccnu.edu.cn>;

Subject:  Re: [Star-cf-l] CF PWG meeting, May 25th, 2023, new time: 9:00 (BNL time)

 

Dear Bijun

On the last part of the 1st paragraph, it might be worth to look at these

2D plots for a few different pT regions. Thank you and sorry for bothering

you several times with these E-mails…

Best regards, ShinIchi

2023/05/31 11:00、EsumiShinIchi <esumi.shinichi.gn AT u.tsukuba.ac.jp>のメール:

Dear Bijun

Thank you very much for very good additional studies. I would agree

with you that phi* and phi cuts are equally good based on your plots.

I would like to ask a few more questions, do you know why the size

of the hole in page 4 are almost independent of the radius choice of

phi*, which is counter intuitive. If the merging is happening inside the

TPC, I would expect some dependence according to the previous

studies. Could you remind me what is the exact formula for your

phi* = phi + (charge_sign) * Fun(pT, B-field, radius)?

Is it like this?  phi* = phi + sgn * asin(0.075*rad/pt);

Another question, do you know why we do not see a significant merging

effect in the forward rapidity case? I thought it could be shorter in terms

of the number of hit in the TPC for the forward tracks (although the actual

track length might be longer because of the theta angle), so that merging

and/or splitting effect might be even more severe in the forward region.

So could you please plot "nFitHit vs eta (or rapidity)” with your track

quality and PID selections?

My last question, that I did not fully understand your last sentence,

"When I calculate the weight of same events distribution using CRAB,

I use the raw qinv to calculate the weight.” What does it mean? We would

need to use the generated (un-smeared) momentum (or qinv) for the

weight calculation with CRAB, but we would need to use the reconstructed

(smeared) momentum (or qinv) for filling the histograms to get the

correlation function in order to include the effect from the momentum

resolution on the correlation including the coulomb effect. If you mean

“raw” as “un-smeared”, it sounds OK, but you still need to use the

“smeared" qinv for making the real and mixed pair distributions. You

would also need to do this correction in an iterative way, since you do

not know the final results to start with… Thanks again for your follow up.

Best regards, ShinIchi

2023/05/30 23:21、樊碧君 via Star-cf-l <star-cf-l AT lists.bnl.gov>のメール:

Hi Esumi, Grigory, Hanna, and all,

I have tried the phi star method to do the track merging effect at 3.2 GeV, and the details and the comparison of Corelation functions of delta phi and delta phi star are shown in the attachment, they are consistent within error; What's more, When I calculate the weight of same events distribution using CRAB, I use the raw qinv to calculate the weight. Thank you for your nice comments!

Best regards,

Bijun

 

------------------ Original ------------------

From:  "樊碧君"<bjfan AT mails.ccnu.edu.cn>;

Date:  Thu, May 25, 2023 05:31 PM

To:  "Hanna Paulina Zbroszczyk"<hanna.zbroszczyk AT pw.edu.pl>; "star-cf-l"<star-cf-l AT lists.bnl.gov>;

Subject:  Re:[Star-cf-l] CF PWG meeting, May 25th, 2023, new time: 9:00 (BNL time)

 

Dear All,
             Please find my slides for today meeting:
https://drupal.star.bnl.gov/STAR/system/files/KK_3p2GeV_CF_0525_pwg.pdf

Best and regards,
Bijun

 

 

------------------ Original ------------------

From:  "樊碧君"<bjfan AT mails.ccnu.edu.cn>;

Date:  Wed, May 24, 2023 08:48 AM

To:  "Hanna Paulina Zbroszczyk"<hanna.zbroszczyk AT pw.edu.pl>; "star-cf-l"<star-cf-l AT lists.bnl.gov>;

Subject:  Re:[Star-cf-l] CF PWG meeting, May 25th, 2023, new time: 9:00 (BNL time)

 

Dear Hanna, Toshihiro, and All,

If time permit, I would like to present an update on the k+ femtoscopy at 3.2 GeV.

Could you please add me to the agenda?  Thank you!

Best,

Bijun

 

------------------ Original ------------------

From:  "Hanna Paulina Zbroszczyk via Star-cf-l"<star-cf-l AT lists.bnl.gov>;

Date:  Tue, May 23, 2023 03:04 PM

To:  "star-cf-l"<star-cf-l AT lists.bnl.gov>;

Subject:  [Star-cf-l] CF PWG meeting, May 25th, 2023, new time: 9:00 (BNL time)

 

Dear CF Activists,

We will have our weekly CF PWG meeting on Thursday, May 25th, 9:00 AM 
(BNL time).

Please note that this week we start at a new time (30 minutes earlier than before).

If you would like to contribute, please let us know.

Please try to post your slides at your earliest convenient.
We will connect via Zoom. Please find the connection details under the
meeting webpage.

Thank you,
Best regards,
Toshihiro and Hanna

https://drupal.star.bnl.gov/STAR/blog/luoxf/correlations-and-fluctuations
https://drupal.star.bnl.gov/STAR/blog/gos/correlations-and-fluctuations-preliminary-plots 

Hanna Paulina Zbroszczyk

PhD DSc Eng, Professor WUT

E-mail: hanna.zbroszczyk AT pw.edu.pl

Tel: +48 22 234 5851 (office)

Address:

Warsaw University of Technology

Faculty of Physics

Nuclear Physics Division

Koszykowa 75

Office: 117b (via 115)

00-662 Warsaw, Poland

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