STAR HardProbes PWG

[Gabe Dale-Gau <gdaleg2 AT uic.edu>]

HI Isaac,

Thank you for these helpful comments. I have updated the paper draft to include all suggested changes and uploaded the new version at the same location I provided in this email chain.

I am still working to update the analysis note, but thought I would respond for now with the paper draft changes.

Please find individual comment responses below.

Thanks,

Gabe

Paper draft:

Title -- lowercase s, upright 'N' subscript (and elsewhere, e.g. end of introduction).

 

Done.

 

8. I would specify "Some key signatures" here so it's clear you don't mean this to be a comprehensive list.

 

Done.

 

38. You go very quickly into analysis techniques (jet-track correlation, etc.) without discussing the data: e.g. how/when the data were taken, what the selections are, etc. And it is okay not to go too in depth on the STAR subsystems you use, but there should then be links to the relevant NIM paper for each subsystem.

 

Added TPC and ToF NIM papers to references. Cited in methods section.

 

42. "radius"

 

Done.

 

57. Should it really be "all tracks in an event" or "each track in an event"? (I.e. how many tracks are paired with each jet axis for the ME?)

 

Changed to “each track in an event”. We see an average of 3 or 4 tracks above 3 GeV in the Au+Au events considered. This number grows significantly with an adjusted pTconst minimum.

 

69. I don't think it will be clear to the reader how the position of that circular region is decided. -> "a circular region centered on the leading jet axis with a radius..." or similar.

 

Good point, added this clarification.

 

91. Hmm maybe this is a subtle point, but I would prefer "introduced when reconstructing jets" or "which must be considered when studying reconstructed jets" or something. "introduced by the jetfinder" makes it seem like it's a flaw in anti-kT. Similar comment for l. 89.

 

I see what you mean. I changed the phrasing to “reconstructing jets” so it doesn’t seem aimed at the algorithm.

 

94. "two"

 

Ah yes, another typo that evaded me

 

98. It's up to you, but I would recommend something like "p+p\oplus Au+Au" rather than the parentheses.

 

Changed to \oplus for now, we can iterate further on this terminology if necessary.

 

134. "radius"

 

Done.

 

135. I'm not sure what you mean with this sentence. There would also be a selection on pseudorapidity, for example. By the way, speaking of that I'm not sure if you ever mention that this is at midrapidity, right?

 

Added a sentence on pseudorapidity selection at line 44 (beginning of methods).

Also removed the “leading” terminology, opting instead to say “only the highest pT jet in each event is considered”

 

142. In the proceedings from HP'23, it was "the hardness of fragmentation within the sample of jets." whereas now it's "...of the initial parton scattering within the sample of jets." To me the former is more correct and I would prefer if it were changed back. 

 

 

Changed back for now, I suspect this is a language point that will need to be changed again as “fragmentation” is a term that often refers to a specific observable that I do not report. I was trying to move away from such confusion with the re-phrase. Maybe I can define terminology earlier in the paper to clarify what is meant by fragmentation in this context.

 

 

174. Math 'R' (also 178).

 

Done.

 

177. "show that for anti-kT..."

 

Done.

 

180. I think you're using the word "hint" here because you don't want to make too strong a conclusion about the actual physics, given the extension to be made to e.g. lower pTcons and the caveats e.g. the leading jet selection bias. But the data that you have don't show a hint, they show definitively that within precision, there is no baryon enhancement. So I would reframe slightly to actually make the physics connection (from baryon enhancement -> medium modification to particle composition; the enhancement being the observed figure, the modification to particle composition being the physics effect) and flip the logic from ~"evidence of no ___" to ~"no evidence of ___": "We see no evidence for medium modification to...". Then or before, caveats can be added to that statement as necessary.

 

Yeah, this is exactly why I was using the word “hint”. I’m still not fully certain how strong to make the physics interpretation statement, but we can work that out in GPC before submitting the paper. Changed to “no evidence of” for now, will add further framing moving forward.

 

186. It's not vital for now, but at some point the references will need a lot of work. Please take a look if you have some time.

 

Yeah, I noticed the format is all messed up. I will look into this and fix it. This is an issue that arose when I implemented the suggested bibliography style from the PLB website. The style is: \bibliographystyle{elsarticle-harv}. When I compile using \bibliographystyle{plain}, I do not have this issue. Either I will see if the plain style is acceptable for submission, or work within my bibtex file to trick the references into looking better.

 

General:

 

Some points that weren't discussed which I think could be were:

the quark vs. gluon aspect. I know you're not including any radius dependence, but it may be good to point out that given the kinematics at STAR and the pTcons selection, you probably have a decently pure quark-jet sample. Also, it would be nice if there were a bit of discussion on the reason for the discrepancy between the inclusive pp (AA) and in-jet pp (AA). You point to the ALICE reference, but I think more could be said here since it's such a salient feature of the plot.

 

This is a good point. I will work on adding more interpretation for the p+p discrepancy.

Added a note on quark/gluon fraction at line 183, will add a reference to back up this claim.

 

It's also a bit light on physics conclusions/takeaways. In e.g. the summary & conclusions, I think it would be good to make one further step from what we observe to what it might mean. Of course, it's a tightrope walk between not making it clear to the reader what physics we're trying to learn from the study and speculating too much as an experimentalist. But I thought you did a good job in l. 27 in the introduction of laying out the physics motivation. You can kind of repeat that here for the people who skip to the conclusions first, but saying instead now that we've seen the results "This study addresses the open question of..., with some evidence that the ... is not modified by..." My comment on l. 180 actually also would address this somewhat, now that I think about it.

Systematics were also never mentioned. You don’t have to get too technical if you want to keep it streamlined, but something like “Systematics related to X, Y, and Z were considered, with X being leading in [insert kinematic range]…”, at minimum, really needs to be included. 

 

Added a paragraph at line 136 to cover the basics of systematic evaluation as suggested.

 

Analysis note:

 

The proton m^2 fit in the 3 < pT < 3.5 GeV range doesn't look very good, but I guess this is irrelevant because it's still low enough pT to be in the bin-counting region, right?

 

Yes, I will remake these figures excluding the proton fit, as it is not used in the analysis. This fit was only employed as an internal cross-check.

 

Thanks for including a clear explanation of the 3-track consideration for the background studies. I think that will help clear up the questions of anyone reading through it who didn't read the email chain earlier.

 

Although for the paper it is a choice to either include or not include some technical details, for the analysis note there are some things which really need to be included (e.g. run year, dataset, centrality definition, bad runs, all event, track, jet selections, any relevant QA plots, etc., etc., etc.). I would almost say the shorter your paper, the longer your analysis note should be :).

 

I will add these details to the Analysis note.

 

By the way, speaking of the centrality definition, did you and Tanmay manage to get the centrality definition for Run 14 that you've been using made an official part of RefMultCorr?

 

We met with the Centrality group a few times about 6 months ago on this point. They pointed us to the proper tools for building a centrality definition and we followed the procedure. We have a working definition that is very similar to the previous productions. However, I do not think we ever presented the final version to the centrality group for final approval. I will follow up with Tanmay to make sure we get this pushed through for approval.

On Mon, Jul 1, 2024 at 6:05 PM Mooney, Isaac <isaac.mooney AT yale.edu> wrote:

Hi Gabe,

Thanks for the nice draft and analysis note. Sorry for my long delay in getting comments back to you. Overall I think the analysis is ready to move to GPC review, although I have some general comments about the structure of the paper and abstract (none are showstoppers). 

Thanks,

Isaac

Paper draft:

Title -- lowercase s, upright 'N' subscript (and elsewhere, e.g. end of introduction).

8. I would specify "Some key signatures" here so it's clear you don't mean this to be a comprehensive list.

38. You go very quickly into analysis techniques (jet-track correlation, etc.) without discussing the data: e.g. how/when the data were taken, what the selections are, etc. And it is okay not to go too in depth on the STAR subsystems you use, but there should then be links to the relevant NIM paper for each subsystem.

42. "radius"

57. Should it really be "all tracks in an event" or "each track in an event"? (I.e. how many tracks are paired with each jet axis for the ME?)

69. I don't think it will be clear to the reader how the position of that circular region is decided. -> "a circular region centered on the leading jet axis with a radius..." or similar.

91. Hmm maybe this is a subtle point, but I would prefer "introduced when reconstructing jets" or "which must be considered when studying reconstructed jets" or something. "introduced by the jetfinder" makes it seem like it's a flaw in anti-kT. Similar comment for l. 89.

94. "two"

98. It's up to you, but I would recommend something like "p+p\oplus Au+Au" rather than the parentheses.

134. "radius"

135. I'm not sure what you mean with this sentence. There would also be a selection on pseudorapidity, for example. By the way, speaking of that I'm not sure if you ever mention that this is at midrapidity, right?

142. In the proceedings from HP'23, it was "the hardness of fragmentation within the sample of jets." whereas now it's "...of the initial parton scattering within the sample of jets." To me the former is more correct and I would prefer if it were changed back. 

174. Math 'R' (also 178).

177. "show that for anti-kT..."

180. I think you're using the word "hint" here because you don't want to make too strong a conclusion about the actual physics, given the extension to be made to e.g. lower pTcons and the caveats e.g. the leading jet selection bias. But the data that you have don't show a hint, they show definitively that within precision, there is no baryon enhancement. So I would reframe slightly to actually make the physics connection (from baryon enhancement -> medium modification to particle composition; the enhancement being the observed figure, the modification to particle composition being the physics effect) and flip the logic from ~"evidence of no ___" to ~"no evidence of ___": "We see no evidence for medium modification to...". Then or before, caveats can be added to that statement as necessary.

186. It's not vital for now, but at some point the references will need a lot of work. Please take a look if you have some time.

General:

Some points that weren't discussed which I think could be were:

the quark vs. gluon aspect. I know you're not including any radius dependence, but it may be good to point out that given the kinematics at STAR and the pTcons selection, you probably have a decently pure quark-jet sample. Also, it would be nice if there were a bit of discussion on the reason for the discrepancy between the inclusive pp (AA) and in-jet pp (AA). You point to the ALICE reference, but I think more could be said here since it's such a salient feature of the plot.

It's also a bit light on physics conclusions/takeaways. In e.g. the summary & conclusions, I think it would be good to make one further step from what we observe to what it might mean. Of course, it's a tightrope walk between not making it clear to the reader what physics we're trying to learn from the study and speculating too much as an experimentalist. But I thought you did a good job in l. 27 in the introduction of laying out the physics motivation. You can kind of repeat that here for the people who skip to the conclusions first, but saying instead now that we've seen the results "This study addresses the open question of..., with some evidence that the ... is not modified by..." My comment on l. 180 actually also would address this somewhat, now that I think about it.

Systematics were also never mentioned. You don’t have to get too technical if you want to keep it streamlined, but something like “Systematics related to X, Y, and Z were considered, with X being leading in [insert kinematic range]…”, at minimum, really needs to be included. 

Analysis note:

The proton m^2 fit in the 3 < pT < 3.5 GeV range doesn't look very good, but I guess this is irrelevant because it's still low enough pT to be in the bin-counting region, right?

Thanks for including a clear explanation of the 3-track consideration for the background studies. I think that will help clear up the questions of anyone reading through it who didn't read the email chain earlier.

Although for the paper it is a choice to either include or not include some technical details, for the analysis note there are some things which really need to be included (e.g. run year, dataset, centrality definition, bad runs, all event, track, jet selections, any relevant QA plots, etc., etc., etc.). I would almost say the shorter your paper, the longer your analysis note should be :).

By the way, speaking of the centrality definition, did you and Tanmay manage to get the centrality definition for Run 14 that you've been using made an official part of RefMultCorr?

On May 24, 2024, at 15:04, Gabe Dale-Gau <gdaleg2 AT uic.edu> wrote:

Dear HP-Conveners,

We would like to request GPC formation for our paper Baryon-to-Meson Ratios in Jets from Au+Au and p+ p collisions at \sqrtS N N = 200 GeV. 

A first draft of the paper can be found here: https://drupal.star.bnl.gov/STAR/system/files/PtoPi_InJets.pdf

The paper proposal page with draft analysis note and paper details can be found here: https://drupal.star.bnl.gov/STAR/blog/gdalegau/Baryon-Meson-Ratios-Jets-pp-and-AuAu-Collisions-200-GeV

Our target journal is PLB.

Please let me know if you have any comments or if there is anything else I can provide to help move this paper forward.

Thanks!

Gabe