STAR Correlations and Fluctuations PWG

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

Dear Kehao,

I am glad to see the progress of your analysis.

Find below my questions after today’s presentation. 

I comment slide-by-slide, I understand that you work on the presentation that is intended to be discussed during PWGC preview. 

S10: show here please the comparison of 2 correlation functions, with and without cut (as an example, show one from backup slides) to understand what is the impact of two-tracks effects on measured correlation function

S13: Mis-id correction: which pair combinations do you include here: (SB - SB) + (SB+S) + (S+SB)?

Show please  \lambda_{pairpurity-signal} and \lambda_{pairpurity-sideband} as a functions of k*

Do the values add up to unity? Please show them, indicating the individual contributions for the numbers mentioned in the formula.
Why do you include only primary_proton and primary_{\xi} in the sideband case (and only in that case)?

Residual correction: Why do you consider only the case of a primary proton and not a primary Xi. What happens if the proton is non-primary and the Xi is, or if neither are primary particles?
Please show the fractions of these pair combinations as a function of k*

Provide more details on how you determine the 1% misidentification correction and the 3% residual correction.

S14: you use different terms here: primary, purity, please make them consistent with terms used in the formula describing raw correlation function.

Regarding the pair purity corrections and how they are treated in the analysis of three different runs of Au-Au collisions:

Simply adding the individual correlation functions is mathematically incorrect. When dealing with fractions, the proper approach is to sum the numerators and denominators separately and then calculate the correlation function from these combined values.

During today's discussion, you mentioned that you add the three correlation functions together using weights. I need to clarify how these weights are determined. Are they based on the number of events? The number of pairs contributing to the correlation function? The numerator? The denominator? Additionally, do you apply the weights to the entire correlation function, or do you consider each bin of the correlation function separately?

I have an idea of how this could be done, but I need to confirm your method first, as it might already align with what you have implemented.

S21: In general, you should be prepared to explain how the estimated strong interaction (SI) parameters connect to the equation of state (EoS) for neutron stars. Your analysis does not discuss any physics related to neutron stars or the EoS, which you mentioned in your abstract.

S23: Following the approach used in other analyses, please include model predictions (e.g., UrQMD) with Lednicky-Lyuboshits (LL) parametrization, and use the SI parameters you extracted from your studies for comparison. While HAL QCD curves are acceptable, it is better to make direct comparisons using consistent models.

Furthermore, in your proposed Fig. 4, you mention HAL QCD parameters, where the effective range of interactions is over 5 fm smaller than your outcome. Showing agreement between UrQMD predictions and STAR data suggests weak sensitivity to the exact values of SI parameters.

S24: Here again, you compare source sizes, but for the data, you use the LL model, while for UrQMD, you use HAL QCD. You should use the same parametrization (LL), as your goal is to extract new SI parameters. It would also be beneficial to show the correlation between extracted parameters, such as f0, d0, and RG

S34: Please display the transformation matrix already normalized for each k* indicated on the vertical axis, as used in your analysis (I assume).

S35: Clarify the distinction between residual correction and feed-down correction, as having both is potentially confusing. You should apply a correction that already includes residual correlations and the fractions of given pairs (S35, corrections 3 and 4).

I hope it helps, 

We can discuss all these during one of the next CF PWG meetings,

Kind regards,

Hanna

Prof. Hanna Zbroszczyk, PhD, DSc, Eng.

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 Kehao Zhang (via star-cf-l Mailing List) <star-cf-l AT lists.bnl.gov> w dniu 12.12.2024, o godz. 14:49:

Dear convenors,

Sorry，seems like there's a bug when opening the previous link.Please use the following link:https://drupal.star.bnl.gov/STAR/system/files/zkh_lala_1212_pwg.pdf

Best regards,

Kehao

 

 

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

From:  "STAR Correlations and Fluctuatio"<star-cf-l AT lists.bnl.gov>;

Date:  Thu, Dec 12, 2024 07:10 PM

To:  "STAR Correlations and Fluctuatio"<star-cf-l AT lists.bnl.gov>;

Subject:  Re: [[Star-cf-l] ] CF PWG meeting, December, 12th, 2024

 

Dear convenors,

Please find my slides in the link below : https://drupal.star.bnl.gov/STAR/system/files/zkh_lala_1212_pwg.pdf

Best regards,

Kehao

 

 

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

From:  "STAR Correlations and Fluctuatio"<star-cf-l AT lists.bnl.gov>;

Date:  Mon, Dec 9, 2024 09:43 PM

To:  "STAR Correlations and Fluctuatio"<star-cf-l AT lists.bnl.gov>;

Subject:  [[Star-cf-l] ] CF PWG meeting, December, 12th, 2024

 

Dear CF Folks,

We invite you to join the weekly STAR CF-PWG meeting on Thursday, December,  12th, 2024:

Time: 9:00 am (EDT), 3:00 pm (CET), 7:30 pm (India), 10:00 pm (China)

Please try to post your slides at your earliest convenience, preferably at least one day before the meeting.

We will connect via Zoom:

Zoom link: https://cern.zoom.us/j/67357482915?pwd=NTEzV0lJc2o1UDRoMVMzQnk0YTBxUT09 // Passcode: 246711

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

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

We already have scheduled 4 contributions.

If you have any additional topics you’d like to include in the discussion, please let us know.

We look forward to seeing you all next Thursday.

Kind regards,
Nu and Hanna

prof. dr hab. inż. Hanna Zbroszczyk
E-mail: hanna.zbroszczyk AT pw.edu.pl
Tel: +48 22 234 5851 (biuro)

Adres:
Poltechnika Warszawska

Wydział Fizyki
Zakład Fizyki Jądrowej
ul. Koszykowa 75
Biuro: 117b (via 115)
00-662 Warszawa