STAR HardProbes PWG

[Barbara Trzeciak <barbara.trzeciak AT gmail.com>]

Hi Xinyue,

thank you for the answers and the new note. They look good to me.

 

Regarding the tracking efficiency, there is currently a discussion on a common way of estimating the sys. unc. on the tracking within STAR.  

The approach may still change once you further work on the paper, but for now please make sure with Jan that you use the same method.

My suggestion is to use 3% per track (as Jan has) + sys. unc. from variations of nHitsFit cut. 

Once you unify the tracking efficiency unc. approach with Jan, for me the paper is good to go to GPC.

Cheers,

Barbara 

On Fri, Mar 10, 2023 at 7:18 PM Xinyue Ju <xinyju AT gmail.com> wrote:

Hi Babara,

Thank you for your valuable comments. Please find the updated analysis note on the following link, it will be updated to the paper proposal web page soon.

https://drupal.star.bnl.gov/STAR/system/files/Run14DplusAnalysisNote.pdf

Here are some explanations for the comments:

-p10: I add a table with all the topo. cuts

-Fig. 5, the cut value here is the TMVA weights to determine the real cuts, I add some explanation on p10

-p11: I fit the bkg. function to the wrong sign distribution first then fit to the right sign distribution plus a Gaussian function

-p14: I added momentum resolution plots 

-Fig. 12 left: I checked and it is due to low statics on that bin, and we require the kaon pT > 0.3, so this will not contribute to kaon PID

-p17: I added the fit function and lines on the plot

-p20: yes the stat. fluctuation was removed, I added a description on p22

-p20, 21: no it's the total TPC tracking uncertainties. The average is 8% on the full pT range actually. There are some fluctuations because I calculated it bin by bin. I can set it to 8% on all pT regions.

-p20: PID sys. unc. for run14 and run16 is considered to the same value of 3%, I change the description on this.

- Fig. 18: I removed this data point before because it is not included in the run14+run16 spectra. I added the 40-80% 0-0.5 GeV data point in Fig.19 now.

- p29: I added a new total cross-section including Xi_C on p31. The number in Tab. 6 is the total cross-section of D0 D+ Ds and Lc, we also explain this in the Dplus paper draft. Because there is no measurement of Xi_C close to RHIC energy, it could be arbitrary if we take the number from PYTHIA or ALICE p+p. We think it is better to report the total cross-section of  D0 D+ Ds and Lc here

Best Regards,

Xinyue

Barbara Trzeciak via Star-hp-l <star-hp-l AT lists.bnl.gov> 于2023年1月23日周一 22:15写道：

Hi Xinyue,

the analysis note looks good. 

I have a few comments and questions:

- p10: please add a table with all the cut values, for the 6 pT and 3 centrality bins. 

Also, it would be useful if you add plots like Fig.5 but for other pT and centrality bins. It can be in an appendix, or just a link to a separate document with all the plots.

- Fig. 5 :"The significance (green) achieves its maximum value when the cut value is 0.535" - it's not explained in the text what is the cut that is mentioned here. 

- p11: do you fit your bkg. function to the correct and wrong sign distribution in the side-band regions ?

- p14: do you have momentum resolution plots for pi and K ? It would be nice to add them to the AN and refer to another note in case they are already shown somewhere else for 2014 data. 

- Fig. 12 left: do you know why there is this jump up for the first point in the Kaon nSigma cut efficiency ?

- p17: "The TOF matching efficiency, TPC PID efficiency, and TPC PID efficiency distributions are fitted with the pol8 function to extrapolate to full pT range" - each of this efficiency is fitted separately with a pol8 function ? Would be good to see some examples of these fits. 

- p20: have you taken into account the Barlow criterion when assigning the sys. unc. from the cut variations ? This procedure should be followed to avoid accounting for stat. unc. in the sys. unc. estimation. 

This approach was used for 2016 data analysis and I think it should be consistently used here as well. 

- p20, 21: TPC tracking efficiency - your sys. unc. numbers for D meson are quite small in some pT bins. What is your TPC tracking systematic uncertainties for a single particle ?  In 2016 this number is ~3%, and since you have 3 daughters that gives ~9% (3*3%) for a D+/- meson.

- p20: PID sys. unc. are smaller than for 2016 data - I think it's better if the same approach is used for 2014 and 2016. 

- Fig. 18: why don't you include the 0.5-1 GeV/c bin for 40-80% centrality ? The signal significance there is more than 5sigma. 

- p29: of the pT spectra at unmeasured low pT range is known -> of the pT spectra at unmeasured low pT range is not known

- p29: It's not clear to me if you included Xi_C contribution to the sys. unc. on the total charm production cross section ? Page 25 ("By quoting this into systematic ... ") suggests so, but the number in Tab. 6 is the same as you showed before. 

Cheers,

Barbara

On Tue, Jan 17, 2023 at 11:05 AM Barbara Trzeciak <barbara.trzeciak AT gmail.com> wrote:

Hi Jan, Xinyue,

thanks a lot for the note. I will have a look asap and let you know my comments.

Just wanted to ask about the total charm cross section on which we recently had discussion in the PWG meeting.

There were a few questions/suggestions related to the treatment of the sys. unc. 

Xinyue, have you had a chance to address these comments and include them in the analysis note ? 

Cheers,

Barbara

On Sat, Jan 14, 2023 at 5:26 AM Vanek, Jan via Star-hp-l <star-hp-l AT lists.bnl.gov> wrote:

Hello Everyone,

Xinyue made some updates to the Run14 analysis note. The new version is uploaded to the paper proposal web page:

https://www.star.bnl.gov/protected/heavy/vanekjan/Dpm_web/Home.html

Best regards,

Jan.

---

Od: Star-hp-l <star-hp-l-bounces AT lists.bnl.gov> za uživatele Vanek, Jan via Star-hp-l <star-hp-l AT lists.bnl.gov>
Odesláno: pátek 13. ledna 2023 12:08
Komu: STAR HardProbes PWG <star-hp-l AT lists.bnl.gov>
Předmět: [Star-hp-l] D+- Run14 analysis note

 

Hello Everyone,

I'm happy to let you know, that I have just uploaded the Run14 D+- analysis note to the paper proposal web page:

https://www.star.bnl.gov/protected/heavy/vanekjan/Dpm_web/Home.html

Please let us know if you have any questions or comments. Thank you.

On behalf of the PAs, best regards,

Jan.

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