STAR Correlations and Fluctuations PWG

[Hanna Paulina Zbroszczyk <hanna.zbroszczyk AT pw.edu.pl>]

Hi Bijun,

Here the correct content comes:

Splitting should be removed/eliminated with SL cut, developed many years ago and successfully applied in most HBT / femto analysis at STAR. nHITs criterium does *not* remove split tracks in case of two-particle correlations. 

Please read more about it in the old pion-pion STAR paper for Au+Au collisions at \sqrt{s_NN} = 200 GeV published around 2005.

Purity refers to the fraction of pure pairs: Pair_purity(q_inv) = Pur1(p1)*Pur2(p2). In case of identical charged kaon correlations, I suggest following procedures for identical pions. 

Resolution means smearing the particles’ momenta due to the finite detector’s resolution. Many people currently work on this, and please come back to the contributions from last week’s PWG CF meeting. 

Usually, people estimate error bars for single points of the correlation function and the extracted parameters separately. Sometimes it is enough to include systematics only in the case of extracted parameters. As I saw in your slides, I mentioned both that you calculated error bars for single points of your correlation function. 

At this moment, results where you did not apply the Barlow test, look better (of course Barlow test should be applied. However, there is a question if you are able to improve them very soon?). If not, I it is better to show results without Barlow test applied. Please update your figures accordingly. Once ready, please prepare the corresponding entry:

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

I understand that before you move forward, more checks are needed (including e.g. implementing the current anti-splitting solution).

Thanks,

Hanna

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

Wiadomość napisana przez 樊碧君 <bjfan AT mails.ccnu.edu.cn> w dniu 14.08.2023, o godz. 19:50:

Hi Hanna,

Thank you for your comments, and I prepared short slides to answer your question at here: https://drupal.star.bnl.gov/STAR/system/files/KK_CF_pwg_response.pdf

Please find my answer in slides: 1-3 for systematic uncertainties of CF; slides: 4-5 for extracted parameters.

Cheers,

Bijun

 

 

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

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

Date:  Sun, Aug 13, 2023 11:14 PM

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

Cc:  "Hanna Paulina Zbroszczyk"<hanna.zbroszczyk AT pw.edu.pl>;

Subject:  Re: [Star-cf-l] CF PWG meeting, August 10th, 2023, time: 9:00 (BNL time)

 

Hi Bijun,

I went through your slides from the last PWG meeting. I am glad to see the progress of charged kaon femtoscopy at FTX.

Regarding systematic uncertainties of single points of your correlation functions:

Your systematic uncertainties look suspicious.

From your slide 19, I assume you included: DCA, n\sigma, \delta \phi*, N_hits, mass^2.

What about other contributions: purity, resolution, splitting, merging (any impact from \delta \phi* vs. \delta \eta ?)

Moreover, I guess the Barlow test you applied caused your systematics to be so different if we look at separate bins of your correlation functions. Can you demonstrate your systematic uncertainties when you don’t apply the Barlow test?

All these issues we need to clarify before we consider preliminary labels to grant (slide 21).

Regarding extracted parameters (R, \lambda):

Can you remind me how you consider the Coulomb factor?

Am I right that you start with R = 3 fm, and then you find a better value regarding the extracted value of the source size from the measured correlation function (that includes both QS and COUL)?

What contributions do you include to estimate the systematic uncertainty of the extracted parameters (R, \lambda)?

I assume all of these you included to evaluate the systematic uncertainties in the case of separate bins of the correlation function? Am I right? What about the impact of different fitting ranges and inclusion/exclusion first one or two bins of the correlation function? How do these contribute to your systematic uncertainties in the case of the extracted parameters?

Before we grant preliminary for data points from the figures from slide 23, we need to clarify those.

Thanks,

Hanna

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

Wiadomość napisana przez 樊碧君 via Star-cf-l <star-cf-l AT lists.bnl.gov> w dniu 10.08.2023, o godz. 14:24:

Dear All,

My slides can be found here: https://drupal.star.bnl.gov/STAR/system/files/Preliminary_request_KK_HBT_3p2to3p9_Bijun_230810_v2.pdf

Best regards,

Bijun

  

 

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

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

Date:  Tue, Aug 8, 2023 02:38 PM

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

Cc:  "Nonaka"<nonaka.toshihiro.ge AT u.tsukuba.ac.jp>; 

Subject:  Re:[Star-cf-l] CF PWG meeting, August 10th, 2023, time: 9:00 (BNL time)

 

Dear Hanna and Toshihiro,

I 'd like to give an update of about K+K+ femtoscopy at 3.0-3.9 GeV and request the preliminary about K+K+ femtoscopy at 3.2-3.9 GeV. Please kindly add me to the agenda. Thank you very much!

Best,

Bijun

 

 

 

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

From:  "野中俊宏 via Star-cf-l"<star-cf-l AT lists.bnl.gov>;

Date:  Tue, Aug 8, 2023 10:46 AM

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

Cc:  "Nonaka"<nonaka.toshihiro.ge AT u.tsukuba.ac.jp>; 

Subject:  [Star-cf-l] CF PWG meeting, August 10th, 2023, time: 9:00 (BNL time)

 

Dear CF Activists,

We will have our weekly CF PWG meeting on Thursday, August 10th, 9:00 AM (BNL time).

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,

Hanna and Toshihiro

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

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

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