STAR HardProbes PWG

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

Thanks Brennan and Anders.

I'm fine with the new version.

Cheers,

Barbara

On Mon, Sep 23, 2024 at 9:49 PM Anders Knospe <ank220 AT lehigh.edu> wrote:

Brennan and I worked together over Zoom to get this draft. I believe all of Barbara's most recent comments have been implemented, except for the request for cosmetic changes to the results plot. That plot was already shown in its current form in Isaac's talk. Plus, it's now almost 5 a.m. in Japan and Brennan really needs to get some sleep before his presentation. We can implement cosmetic changes for future uses of this plot. We've reordered the description of the analysis, which should now be in the form advocated by Rosi, Barabara, and others. I hope that these slides are now in a state where people are OK with a public presentation. -AK

On Mon, Sep 23, 2024 at 3:40 PM Brennan Schaefer <brs521 AT lehigh.edu> wrote:

Hi.  Another update is posted.

https://drupal.star.bnl.gov/STAR/node/68993/

b

On Mon, Sep 23, 2024 at 1:58 PM Barbara Trzeciak <barbara.trzeciak AT gmail.com> wrote:

HI Brennan,

Thanks for improving the slides. I have a few more comments.

- Add authors (or a collaboration) to the citations 

- s2: Predictions from NRQCD -> Predictions from Pythia 6

- s9: 4.2 GeV BEMC BEMC tower with E > 4.2 GeV

- s10: For clarity, I would add "Low Multiplicity", and so on, on the top of each plot (so that the audience easily understands what are the different plots)

- s13: Figure: I think it's too many symbols now. Either have two legends and on top of the second write "Published", or write e.g. "PLB 786" in the legend, next to the results that are published 

- s13: ideal multiplicity -> charged-particle multiplicity

- s13: I think it would be good to have two separate slides "Results" and then "Summary"

In summary you can write what has been measured, main conclusion and some outlook, e.g. unfolding to N_ch ongoing, comparison to different model and MC predictions to draw physics conclusions

- s14: You don't need this slide anymore

Cheers,

Barbara

On Mon, Sep 23, 2024 at 5:17 PM Barbara Trzeciak <barbara.trzeciak AT gmail.com> wrote:

Hi Brennan,

Thanks for the update. I may still send you more detailed comments later.

I do not insist on changing your introduction. It's useful to know what you intend to say, thanks for explaining, and if it fits your story, that's fine with me.

Regarding TOF PID, you perform a one-sided cut, 1/beta > 0.97, not |1/beta -1 | < 0.03 ?

Cheers, 

Barbara 

On Mon, Sep 23, 2024, 5:05 PM Brennan Schaefer <brs521 AT lehigh.edu> wrote:

Hi Rosi, Barbara, conveners Yi and Sooraj, and HP team, below are responses to recent comments.

A new revision with everything reflected below is here:

https://drupal.star.bnl.gov/STAR/node/68993/

From Rosi

I believe every slide outside of the title should have a title - this is a 15 minute talk, there is no prologue.  Every slide now has a title.

Slide 2 - Include a little bit of the actual reference instead of just a number    Done

Slide 3 - As you were asked by Barbara, please include some statement about the mechanism that caused the decrease vs. multiplicity so what we may learn about the mechanisms is more clear. Include a little bit of the actual reference instead of a number.  I will explain more on the page.  This plot was made by ALICE with the purpose of showing what early NRQCD would predict for J/psi production solely in hard scattering collisions.  It is notable for what it does not contain.  Mechanisms like MPI with gluon density fluctuations, even feeddown from beauty hadrons are omitted here.  The plot was made in essence for the same reason I would like to use it.  It shows the baseline, and it illustrates there is more to the story.

Slide 7 - instead of the BEMC volume, include the eta-phi size of a tower (0.05x0.05) changed

Slide 8 + 9 -> The story is muddled here, the invariant mass plots are towards the end - and the analysis procedure happens prior to the signal extraction.  It seems opinions of commenters vary as to what should go first.  If not, please clarify.

Slide 9 -> Please include the details as I have been asking for over a week.  What are the kinematics of the leading track?  As spelled out, the triggering track: 4.2 GeV/c + BEMC hit as listed on the slide.  I’m not sure what other kinematics you’re looking for.  The associated track?  I just added: p_T > 0.2 GeV/c otherwise it’s not clear to me what else you want here. Any other selection criteria? Already listed: TOF matched && passing slow veto (beta > 0.97) OR other BEMC (E/p selected) electron hits.  The quality cuts are not spelled out explicitly, as they are STAR specific and their associated efficiency is corrected for.

 For E, is this the tower energy or the cluster energy?  If the latter, explain how the cluster is found.  “Events are triggered by from 4.2 GeV/c e± in BEMC”.  The language you proposed earlier reads, “Trigger on, identify electrons”  will this suffice for this talk? You do not talk about whether there is a mass window for your determination of the yield.  I do not use a mass window in this analysis.  I integrate to get the J/psi count.  You don't mention dE/dx.  dE/dx is mentioned on a slide with the detector diagram (slide numbers keep changing) as requested, although more precisely I use the derived quantity nSigmaE.  I have considered it part of track quality, that both trigger and associate must satisfy. I just added also “Mom > 0.2 GeV/c” I also believe this slide would be improved if you first discuss eventwise requirements and then discuss trackwise selections. I’ve just added, “Events are ±40cm from z=0 with vertex quality cut“ to slide 8.  Here it would be useful to discuss how the minbias vs high tower triggered data is used. That is what is meant by the lines on page 9: first “Event activity is characterized using TOF-multiplicity” and then  “Event counts are scaled to min-bias multiplicity”

I still think a PID plot would be useful here..... strictly speaking we do not do PID.  Instead of identifying a track as being an electron, we use TOF to require a minimum beta > 0.97.  Following this cut, most candidates to be paired are probably still pions.  By “veto”, I mean we eliminate tracks that we are very certain are not electrons.

Slide 10 - varied -> dependence (or something like that) updated

Slide 11 - indicate the range for the total systematic uncertainty  updated

Slide 12 - this is really abrupt.  You really should show the result, and then conclusions even if you repeat the plot for both.  Do you want a slide with just the result and no text, followed by the same plot with text added?  While we aren't going to make any statement re-models, you can reiterate what the next steps would be to distinguish between them.  The plot is listed with the caveat emptor about TOFmult.  I have just added the language: “Unfolding is needed to convert TOFmult to ideal multiplicity”

 

From Barbara

- Slide titles would be useful  Every slide now has a title

- Title slide: add conference name (or logo) and dates I added a logo with the date

- s1: With J/psi prod. vs mult. we study more of hard vs soft process rather than the produciton mechanism. We want to explore correlation between hard and soft processes. Would be good to reflect it on this motivation slide, I'm not sure what you want to say with the current statment 

I intend to speak to the interplay between hard and soft processes.  In essence, although we can factorize these probabilities, the middle hard part in the equation will need to produce the heavy quarks in a way that permits hadronization.  Conversely and by way of analogy, I know b and bbar quarks are often emitted back-to-back.

- s2: "Also suppressed in high compared to low multiplicity p+p? " - do you refer to the Pythia6 prediction from the next slide ? I would rather remove the right R_AA plot and move plots from slide 3 to slide 2. Though I don't even know if you need it, it's kind of old story. 

I think there are more links between A+A and p+p than just filling out the multiplicity scale.  For instance, I think percolation has been used to describe suppression of other hadrons in A+A, as well as more recently the faster-than-linear rise in J/psi vs multiplicity.  If you will permit it, I would like to keep this slide.  I also trust your judgement though.  The presentation does not hang on this point, and I won’t push back further if you’ll have me remove it.

- s4:  "consistent across multiple energies" - the rising trend is at multiple energies, but not with the same magnitude. I would make it more clear, as it might be misintrepreted.  I reorganized the sentence to have plural energies, as well as plural rates of production rise.  It now reads:

At multiple energies, J/ψ production has been found to rise with respect to event multiplicity, at rates that are faster than linear.  Barbara, you have eagle eyes!

 

- s4: Add full reference to the STAR paper  Every reference used has been changed to a longer form.

- s6: 2017 STAR p+p 510 GeV -> $p$+$p$ collisions at \sqrt{s} = 510 GeV from 2017  the “p’s” are now italicized.

 

- s6: above 200 GeV p+p -> I guess you mean the sample for the published J/psi vs mult. studies. please make it clear

“4x increase in luminosity above 200 GeV p+p“     changed to:

4x increase in luminosity above J/ψ vs mult. in p+p 200 GeV result

 

- s6: 4.2 GeV/c EMCal -> 4.2 GeV BEMC changed

- s6: Associate tracks from TOF - I guess you mean electrons here. I suggest: Electron ID using TOF (1/beta) or BEMC (E/p requirement)  changed in previous edit

- s6: You could have a separate slide for the data, electron ID, showing some eID related plots. And a separate slide for the invriant mass distrubutions  Notably, I do not have performance plots for electron ID

- s7: This slide should be before s6  the order is changed

- s7: what are "Slow non e± veto" ?  to clarify I added (beta < 0.97)

And TOF is also used for PID, as well as TPC

I think We do not exactly use TOF-PID for electrons.  This loose cut will not distinguish between most electrons and pions.  We use TOF here to veto slow tracks with beta below 0.97.

 

- s8: I would remove this slide, you can add eta covenrage on the previous slide  both slides are greatly changed since this comment was made.  Other reviewers asked for more information.  They can no longer be combined for lack of room

 - s9: I would have this slide also before you show the inv. mass distributions  invariant mass plots are shown after the detector, cut specifics, and the analysis procedure

- s12: Yields -> Normalized yields fixed

- s12: Add references to the published results done

- s12: Figure: Not all of the results are preliminary, please indicate in the legend which results are published  I added a dagger symbol to indicate which one is preliminary

- s13: I don't think we want to discuss the ALICE results. You can have it in backup, compared to STAR published results at 200 GeV, in case someone asks if the difference between RHIC and LHC is expected. Then, based on Pythia8 we can say this particular MC also has energy depdence/ plot moved to backup

- s13: Add reference to the paper   done

- s14: Move references to the individual slides done

- Summary/outllok slide is missing added / combined with results

 

best,

b

On Mon, Sep 23, 2024 at 5:41 AM Brennan Schaefer <brs521 AT lehigh.edu> wrote:

Hi.  I was taking some of the comments as light suggestions.  I will amend according to each one and report back.  b

On Mon, Sep 23, 2024 at 3:38 AM Barbara Trzeciak <barbara.trzeciak AT gmail.com> wrote:

Just a typo in the previous email. Number of the previously sent comments seem to be not addressed.

Cheers,

Barbara

On Mon, Sep 23, 2024 at 9:37 AM Barbara Trzeciak <barbara.trzeciak AT gmail.com> wrote:

Hi Brennan,

Thanks for the updated slides.

It would be good if you go via the comments already sent, it seems number of them are addressed. Also, please address comments from Rosi.

And a few comments to your new version.

- You can call the first slides Introduciton, and my comments on them are still valid

- s8: the signal extraction should be after the analysis procedure, as I suggested, it can be a separate slide, and you can combine dataset informaton with slides with details that Rosi asked for

Cheers,

Barbara

On Mon, Sep 23, 2024 at 8:23 AM Rosi Reed <rosijreed AT lehigh.edu> wrote:

Hi Brennan,

I believe every slide outside of the title should have a title - this is a 15 minute talk, there is no prologue.

Slide 2 - Include a little bit of the actual reference instead of just a number

Slide 3 - As you were asked by Barbara, please include some statement about the mechanism that caused the decrease vs. multiplicity so what we may learn about the mechanisms is more clear. Include a little bit of the actual reference instead of a number.

Slide 7 - instead of the BEMC volume, include the eta-phi size of a tower (0.05x0.05)

Slide 8 + 9 -> The story is muddled here, the invariant mass plots are towards the end - and the analysis procedure happens prior to the signal extraction.

Slide 9 -> Please include the details as I have been asking for over a week.  What are the kinematics of the leading track?  The associated track?  Any other selection criteria? For E, is this the tower energy or the cluster energy?  If the latter, explain how the cluster is found.  You do not talk about whether there is a mass window for your determination of the yield.  You don't mention dE/dx.  I also believe this slide would be improved if you first discuss eventwise requirements and then discuss trackwise selections.  Here it would be useful to discuss how the minbias vs high tower triggered data is used.  I still think a PID plot would be useful here.....

Slide 10 - varied -> dependence (or something like that)

Slide 11 - indicate the range for the total systematic uncertainty

Slide 12 - this is really abrupt.  You really should show the result, and then conclusions even if you repeat the plot for both.  While we aren't going to make any statement re-models, you can reiterate what the next steps would be to distinguish between them.

Rosi

On Sun, Sep 22, 2024 at 9:06 PM Brennan Schaefer <brs521 AT lehigh.edu> wrote:

Hi Barbara, Sooraj, and HP team,

I've just uploaded another revision.  When comments have conflicted with previous commenters' I've tried to accommodate both where possible.

Some notes:

   After the prologue every slide has a title.

   I have added "(beta < 0.97)" to clarify slow veto.  With TOF we do not identify tracks as being electrons, instead we veto some that certainly are not e+/- because they are too slow.

   After the loose TOF-beta cut, we still have mostly pions.

   Slide 17 has been suggested to be added and removed, it is therefore in backup.

   The last two slides are preparation in the chance that I am asked specific questions about MPI.

   Slide 18 is about the spatial distribution of partons, really the form factors seen in the equation on slide 2.

   Slide 19 is about the q^2 relation to the inter-parton impact parameter.

best,

b

https://drupal.star.bnl.gov/STAR/node/68993/

On Sun, Sep 22, 2024 at 3:14 PM Barbara Trzeciak <barbara.trzeciak AT gmail.com> wrote:

Hi Brennan,

Please find below comment on your slides.

- Slide titles would be useful

- Title slide: add conference name (or logo) and dates

- s1: With J/psi prod. vs mult. we study more of hard vs soft process rather than the produciton mechanism. We want to explore correlation between hard and soft processes. Would be good to reflect it on this motivation slide, I'm not sure what you want to say with the current statment 

- s2: "Also suppressed in high compared to low multiplicity p+p? " - do you refer to the Pythia6 prediction from the next slide ? I would rather remove the right R_AA plot and move plots from slide 3 to slide 2. Though I don't even know if you need it, it's kind of old story. 

- s4:  "consistent across multiple energies" - the rising trend is at multiple energies, but not with the same magnitude. I would make it more clear, as it might be misintrepreted.

- s4: Add full reference to the STAR paper

- s6: 2017 STAR p+p 510 GeV -> $p$+$p$ collisions at \sqrt{s} = 510 GeV from 2017

- s6: above 200 GeV p+p -> I guess you mean the sample for the published J/psi vs mult. studies. please make it clear

- s6: 4.2 GeV/c EMCal -> 4.2 GeV BEMC

- s6: Associate tracks from TOF - I guess you mean electrons here. I suggest: Electron ID using TOF (1/beta) or BEMC (E/p requirement)

- s6: You could have a separate slide for the data, electron ID, showing some eID related plots. And a separate slide for the invriant mass distrubutions

- s7: This slide should be before s6

- s7: what are "Slow non e± veto" ?  

And TOF is also used for PID, as well as TPC

- s8: I would remove this slide, you can add eta covenrage on the previous slide

- s9: I would have this slide also before you show the inv. mass distributions

- s12: Yields -> Normalized yields

- s12: Add references to the published results

- s12: Figure: Not all of the results are preliminary, please indicate in the legend which results are published

- s13: I don't think we want to discuss the ALICE results. You can have it in backup, compared to STAR published results at 200 GeV, in case someone asks if the difference between RHIC and LHC is expected. Then, based on Pythia8 we can say this particular MC also has energy depdence/

- s13: Add reference to the paper

- s14: Move references to the individual slides

- Summary/outllok slide is missing

Cheers,

Barbara

On Sun, Sep 22, 2024 at 5:30 PM Brennan Schaefer <brs521 AT lehigh.edu> wrote:

Hi Yi, Sooraj, and HP team, I have posted another revision of the slides with the annotations again removed, and also every to-do item until 6 hours ago finished.  I am also available to iterate quickly over your comments.

https://drupal.star.bnl.gov/STAR/node/68993/

Specifically the comparison to the Raa in heavy-ion collisions was an idea I found in this paper,

   

   J/ψ Production as a Function of Charged Particle Multiplicity in pp Collisions at √s = 7 TeV

   https://arxiv.org/abs/1202.2816

Part of the original motivation for the first measurement of J/psi vs multiplicity was to reach lower multiplicity events using p+p.  In the above ALICE paper it states:

"The multiplicity dependence measured here will allow a direct comparison of the J/ψ production in pp to the one observed in heavy-ion collisions. With a mean value of dNch/dη of 24.1, the highest multiplicity interval shown in Fig. 3, for instance, corresponds roughly to 45– 50% centrality for Cu–Cu collisions at √sNN = 200 GeV [21]. In order to establish whether any evidence for a J/ψ suppression is observed already in pp, a proper normalization is needed. This could be provided by a measurement of open charm production in the same multiplicity bins. Corresponding studies are currently ongoing."

Also, the old model calculation that predicted the opposite behavior, did not feature MPI or percolation, which (as I gather it) are the leading explanations for the enhanced J/psi production in high multiplicity events.  As a follow up question, I would be greatly interested to know if most recent Pythia model calculations in other areas are including these features.  If so, it then looks like this type of measurement has had a large influence.

thanks,

b

On Sun, Sep 22, 2024 at 10:14 AM Yi Yang <yiyang429 AT gate.sinica.edu.tw> wrote:

Hi Brennan,

Thanks for the updated version and explanation. 

Before you have the final version of the talk, I have comments/questions on p2 and p3. 

 - p2: I don't understand the comparison to the RAA in heavy-ion collisions here. As you said in the previous page, the main purpose for this study should be to understand the production mechanism, but nuclear modification is different story. I am not sure if it is good way to do it. 

 - p3: It would be nice to provide a physics reason why the old prediction saying the yield is decreasing (what is the mechanism), not just show the plot. Probably you can (or you already have) combine with p5 to give a better explanation. 

Cheers,

Yi

+++++++++++++++++++++++++++++++++++++++++++++++++++
Yi Yang, Research Fellow
Institute of Physics, Academia Sinica
E-Mail: yiyang429 AT gate.sinica.edu.tw
Tel: +886-2-2789-6709
+++++++++++++++++++++++++++++++++++++++++++++++++++
-----Original message-----
From:Brennan Schaefer<brs521 AT lehigh.edu>
To:star-hp-l<star-hp-l AT lists.bnl.gov>
Date: Sun, 22 Sep 2024 16:41:43
Subject: Re: [[Star-hp-l] ] STAR presentation by Brennan Schaefer for HP2024 submitted for review

Hi Sooraj also Yi and other leaders,

An updated presentation (this one has red annotation of my accompanying thoughts) is linked below.  Most of the suggestions are implemented, a few that require editing plots are maybe some few hours away, but the slides are converging quickly.

https://drupal.star.bnl.gov/STAR/node/68993/

best,

b

On Sun, Sep 22, 2024 at 4:09 AM Sooraj Radhakrishnan <skradhakrishnan AT lbl.gov> wrote:

Hi Brennan,

   Thanks. Please send the updated version as early as possible 

Best,

Sooraj

On Sun, Sep 22, 2024 at 12:09 AM Brennan Schaefer <brs521 AT lehigh.edu> wrote:

Hi Sooraj, I just sent an update on the main plot that I am requesting preliminary for.  I will send an update on the slides really soon (probably less than an hour).  best,   b

On Sun, Sep 22, 2024 at 3:04 AM Sooraj Radhakrishnan <skradhakrishnan AT lbl.gov> wrote:

Hi Brennan,

   Do you have an updated version of your talk?

thanks,

Sooraj

On Fri, Sep 20, 2024 at 6:15 PM Yi Yang <yiyang429 AT gate.sinica.edu.tw> wrote:

Hi Brennan,

We saw an updated version on drupal now, thanks a lot.
Let me give you a very quick first round of comments.
 - Title: please add "Supported in part by" above the DOE logo, please check other's talk. Also, it would be good to add date of your talk there.
 - p1: I would start with the previous measurements on cross section vs pT and polarization and mention the production mechanism is still an open question. Then, introduce these CSM and COM.
 - p2: Not sure if you need this one, I don't know how you will connect it to your results.
 - p3: Need more description on this page, not sure what you want to say on this early predictions.
 - p4: references are need for this plot.
 - p5: small b^bar --> small impact parameter
 - Move p9 p10 (STAR) before p6.
 - p6: It would be nice to have some parameters showing on the plot, like NJ/psi, width, mean...
 - p7: B.EMCal --> BEMC   (2 places)
 - p8: the quality of the plot is not good, can it be improved? Also, can you make the data plots larger? Not easy to know the inserted plot mean, need some description.
 - p9: Add the abbreviations for each subsystem, like (BEMC), (TOF), (TPC), (BBC), (VPD)
 - p9: Remove the line under Vertex Position Detector
 - p10: add eta ranges for TOF and TPC
 - p11: You have a nice list for systematics sources in your preliminary request, I think it would be nice to add here.
 - p12: Add a title on this page: "Result"
 - p13: Not sure if you need this plot here, it would be better to have a summary, what Barbara sent (PYTHIA predictions) might be useful here.

Cheers,
Yi

+++++++++++++++++++++++++++++++++++++++++++++++++++
Yi Yang, Research Fellow
Institute of Physics, Academia Sinica
E-Mail: yiyang429 AT gate.sinica.edu.tw
Tel: +886-2-2789-6709
+++++++++++++++++++++++++++++++++++++++++++++++++++

-----Original message-----
From:webmaster AT star.bnl.gov
To:Star-hp-l AT lists.bnl.gov
Date:Sat, 21 Sep 2024 03:46:48
Subject:[[Star-hp-l] ] STAR presentation by Brennan Schaefer for HP2024 submitted for review

Dear Star-hp-l AT lists.bnl.gov members,

Brennan Schaefer (brennanschaefer AT hotmail.com) has submitted a material for a 
review, please have a look:
https://drupal.star.bnl.gov/STAR/node/68993

Deadline: 2024-09-22
---
If you have any problems with the review process, please contact 
webmaster AT www.star.bnl.gov

--

Sooraj Radhakrishnan

Research Scientist,

Department of Physics

Kent State University

Kent, OH 44242

Physicist Postdoctoral Affiliate

Nuclear Science Division
Lawrence Berkeley National Lab
MS70R0319, One Cyclotron Road

Berkeley, CA 94720

Ph: 510-495-2473

Email: skradhakrishnan AT lbl.gov

--

Sooraj Radhakrishnan

Research Scientist,

Department of Physics

Kent State University

Kent, OH 44242

Physicist Postdoctoral Affiliate

Nuclear Science Division
Lawrence Berkeley National Lab
MS70R0319, One Cyclotron Road

Berkeley, CA 94720

Ph: 510-495-2473

Email: skradhakrishnan AT lbl.gov

--

Rosi Reed
Associate Professor, Physics Department
Lehigh University
(610)758-3907
16 Memorial Drive East Office 406
Bethlehem, PA 18015

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