STAR HardProbes PWG

[tc88qy <tc88qy AT rcf.rhic.bnl.gov>]

Hi Nihar,

   I am one of the PA. So it needs you and Isaac to sign-off.

Qian Yang

On 2025-01-11 09:51, Nihar Sahoo wrote:
> Hello PAs,
>
> Thank you for addressing my comments.
> At the moment, I don't have any further comments. I sign off.
> Once Isaac and Qian will sign it off , we can request PAC to form GPC.
> Please remind us next week if you will not receive any comments.
>
> Best
> Nihar
>
> On 2025-01-09 16:26, wy157543 wrote:
> > Hi Nihar and Isaac,
> >
> > Thank you for your kind comments. The paper and note have been updated
> > and can be accessed at the following links:
> > https://drupal.star.bnl.gov/STAR/system/files/psi2s_paper_pwg_v2.pdf
> > https://drupal.star.bnl.gov/STAR/system/files/psi2s_note_pwg_v2.pdf
> >
> > Below are the detailed replies.
> >
> > For paper:
> >
> > Title: “First observation of charmonium sequential suppression in
> > heavy-ion collisions at  Relativistic Heavy Ion Collider” -> “
> > Measurement of charmonium sequential suppression in heavy-ion 
> > collisions
> > at  Relativistic Heavy Ion Collider”  [ “First …” in title sounds
> > awkward and a reader can judge it. ]
> >
> > I removed the "First" and kept the observation
> > --------
> >
> > Line7: "We report on measurements of charmonium …” -> “We report the
> > measurement of charmonium …”
> >
> > Done.
> > --------
> >
> > L48-51: “…has  been measured in Pb+Pb collisions at …” Better to
> > mention what we observed at the LHC experiments and what more
> > information we can get at RHIC measurement and why it is important to
> > measure at RHIC energy.
> >
> > Done.  The importence for psi2s measurements is described on lines 
> > 60-76
> > --------
> >
> > L90-92: This sentence sounds redundant and you already mentioned in
> > intro. Please drop it.
> >
> > Done.
> > --------
> >
> > L138: “… from data for different BDT cuts, “ it is not clear from the
> > text what are BDT cuts. Please elaborate and avoid words like “cuts”.
> > Use condition or criteria, etc. [Similarly for other places]
> >
> > BDT cut->BDT threshold,
> > Added "by requiring the BDT response to be above a threshold." on
> > line133-134 to introduce "BDT threshold".
> > --------
> >
> > _ Many places “200 GeV” is used, use “ \sqrt s_NN = 200 GeV”
> >
> > Done.
> > --------
> >
> > _ It would be important to point out that what is advantage of using
> > BDT/ supervised ML technique over traditional invariant Mass
> > combinatorial subtraction method. A account will enhance this paper.
> > Please indicate if such comparisons are discussed in AN.
> >
> > The comparison was added in AN (319-322): The jpsi significence is
> > improved from 133 (traditional method) to 170  (ML method) the ML
> > technique did significantly improve signal salience.
> > --------
> >
> > _ L280-289: “While all three measurements are consistent within
> > uncertainties, the centrality dependence in 200 GeV Ru+Ru and Zr+Zr
> > collisions seem to more closely resemble the measurements at 17.3 
> > GeV…”
> > This is not true within uncertainty . “…seem to more closely 
> > resemble….”
> > Please paraphrase.
> >
> > The original content is modified to：
> > While all three measurements are consistent within uncertainties  at
> > comparable $\langle N_{\rm part} \rangle$ values, the centrality
> > dependence trend observed  in $\sqrt{s_{_{\rm NN}}}$ = 200 GeV Ru+Ru
> > and Zr+Zr collisions seems to more closely resembles
> > the measurements at 17.3 GeV than those at 5.02 TeV.
> >
> > "at comparable $\langle N_{\rm part} \rangle$" and "trend" were added
> > to make the expression clearer.
> > --------
> >
> > I think it would be better to make Fig,3 as final money plot for this
> > paper. Whereas Fig.4 and it discussion should come before double ratio
> > vs Npart plot.
> > I find Ratio vs pT plot is less significant, due to uncertainty, than
> > current Fig.3 to convey the message.
> >
> > Fig,3 does convey the more important message. However, if the
> > positions of Fig,3, Fig,4 are exchanged, it is a little strange to
> > discuss ratio instead of double ratio after calculating pp, pA
> > reference. If Fig,4 is placed before calculating pp, pA reference, the
> > discussion of physical results is separated. Another reason is that
> > Fig,3 contains calculations from both models, and therefore they can
> > be introduced together. Personally, I think it would be better to keep
> > the current order. it is not necessary that the money.
> > --------
> >
> > Fig.3:
> > _ Please add in the legend what is that gray band on unity line. It is
> > unclear.
> > _ Can we have p/d+Au 200 GeV CNM effect calculation from Tsinghua 
> > group?
> > That would even strengthen the claim.
> >
> > _ Is there any discussion or information on QGP Temperature from
> > Tsinghua's group calculation?
> >
> >
> > Added " The band at unity represents the relative uncertainty in
> > interpolated $\psi$(2S) to J/$\psi$
> > ratio in $p$+$p$ collisions." to the captain.
> > Regarding the calculation of "CNM effect" and "QGP Temperature",
> > we may need to further consult Tsinghua group.
> > --------
> >
> > ---
> > ----------------------------------------------------------
> > ---
> > For note:
> >
> > 142. I see that after applying the procedure, there is still a
> > residual eta dependence although the phi dependence is nicely removed.
> > Is this caused by the imperfect agreement of the fit with the data
> > especially in the negative rapidity region? Is this non-zero nsigma_e
> > close enough to zero that it produces a minimal effect in the
> > analysis?
> >
> >
> > Yes, the slight \eta dependence that still exists after recalibration
> > does result from slight differences between the fit results and the
> > data, but these differences have little effect on the analysis
> > results. Because the recalibration is only convenient for the
> > selection of nsigmaE cut and the calculation of nsigmaE cut
> > efficiency. In addition, the small deviation is taken into account in
> > efficiency correction since the correction is estimated with a
> > data-driven method.
> >
> > ---
> >
> > 175. Just to make sure I understand, this cut on the invariant mass
> > implies that only Dalitz decays of pi0s are included in the sample,
> > while photon conversion typically falls just outside the requirement,
> > right?
> >
> > Electrons from Dalitz decay are equally good for estimating
> > efficiencies compared to photon conversion. What matters is the
> > electron purity, not its source. The selection of the pairMass cut
> > takes into account both the statistics and the electron purity.
> > For example, in 40–80% centrality, photon conversions are also
> > included to increase statistics. (New 20-40% and 40-80% centrality
> > graphs added)
> >
> > ---
> >
> > 204. This isn't 100% true is it? We see in the Background plot in Fig.
> > 11 that the track pT or p has a correlation of ~ 0.25 for example. And
> > this makes sense given the relation between invariant mass and
> > momentum. Did you check whether the results were modified
> > significantly if the observables which have some degree of correlation
> > with the pairMass were removed from consideration as training
> > features?
> >
> > Fig. 11 includes more information than the features used in ML. Only
> > the features shown in Fig. 17 have been used for identification,
> > all of which have low correlation with pairMass. More detail describes
> > for the features used in ML is added in AN (190-200)
> > ---
> >
> > Eq. 4. I understand the procedure you're following to change the mean
> > and sigma of the embedding nsigma distributions, but the subscripts
> > 1,2,3 were a little confusing to me for a second. Could you either
> > explicitly explain them in the text (e.g. "the numerical subscripts
> > refer to a value in the embedding at the corresponding step in the
> > correction procedure" or similar), or use a less opaque notation?
> >
> > Thanks for your reminding, I have added some content to better
> > describe these steps. (222-227)
> >
> > ---
> > 219. Sorry for this possibly silly question, but isn't there a concern
> > that if you use embedding for signal and data for background that the
> > model may distinguish the two based on some subtle difference not
> > between signal and background but between embedding and data (that is
> > left over after the feature alignment procedure)? Was the training
> > tried with embedding for background as well, and if so was it
> > approximately the same result?
> >
> >
> > We do not see the need to use embedding for background since utilizing
> > data is always better. In fact, we do not have embedding for
> > background since our simulation only embeds psi(2S) signal. Then the
> > question is whether there is any residual difference between data and
> > embedding after the alignment procedure, and if so how would that
> > affect the results. We do not have a clear answer to that since if we
> > know there is a difference we would have corrected it. What we can do
> > is to check the dependence of corrected Jpsi and psi(2S) counts, with
> > raw counts from data and efficiency from machine learning, on the BDT
> > response. A flat distribution is seen in Fig. 19, which shows that
> > embedding agrees with data quite well after alignment. Furthermore,
> > variations in the results from using different BDT cuts are included
> > in the uncertainty, which is another way to gauge the difference
> > between data and embedding
> > ---
> >
> > Fig. 15. Just curious, what is the y-axis here? Is it bin-width and
> > integral-normalized count? Or something else?
> >
> > Yes, it's normalized count
> >
> > ---
> >
> > Fig. 20. I can't tell if my eye is fooling me or not, but it looks
> > like the relative statistical uncertainties on the 0-80% range are
> > slightly bigger than the 40-80% range. Is this true?
> >
> > Yes, this is true for ψ(2S). Because more significant suppression in
> > central collisions for psi(2S) results in worse signal to background
> > ratio.
> > (At BDT cut = 0.7, the signal significance is only 1.7σ.)
> >
> > ---
> >
> > Fig. 25. What should we make of the fact that the Crystal Ball fits
> > are quite poor?
> >
> > Indeed, the templates obtained by ToyMC cannot be perfectly described
> > by the Crystal Ball function. This is an interesting feature and we
> > will continue to investigate that. However, what we take from the
> > fitting are the ratios of various Crystal-ball parameters between Jpsi
> > and psi(2S), which should still be good even if the templates do not
> > fit ver well. In data analysis, Jpsi peak is fit with all Crystal-ball
> > function parameters being free (the fit works well as seen in Figs. 26
> > and 27), while psi(2S) peak fit is constrained by Jpsi fit parameters
> > and the parameter ratios from ToyMC.
> > ---
> >
> > Fig. 28. What is causing the bump ~ 500 MeV? Comparing to e.g.
> > https://drupal.star.bnl.gov/STAR/system/files/JianZhou_hf_20220120_v3.pdf
> > s. 14 [from run 16], this bump does appear but a) to a seemingly
> > lesser extent (for the same set of cuts), and b) with more of a
> > centrality dependence. Do you have an insight into the difference?
> >
> > In terms of the bump, I always think that comes from interplay of two 
> > effects:
> > i) efficiency increases with pt as electron's dE/dx increases with pt
> > and thus more likely to generate a TPC hit, and also the track length
> > increases with pt;
> > ii) on the other hand, electron's efficiency decreases with pt since
> > at low pt electron tracks can bend through TPC boundaries and still
> > get reconstructed while at high pt electron tracks are straight and
> > they are more likely to be lost in the boundaries.
> >
> > The major differences between Jian's analysis and this analysis are
> > high luminosity in run16 which could affects TPC performance in terms
> > of the bump. The variation in TPC occupancy from central to peripheral
> > events is much larger for Au+Au than for Isobar, which is why Jian
> > seems a larger centrality
> > dependence
> >
> >
> > Best,
> >
> > Yan and PAs
> >
> >
> >
> > > -----原始邮件-----
> > > 发件人: "Mooney, Isaac" <isaac.mooney AT yale.edu>
> > > 发送时间:2025-01-05 09:06:27 (星期日)
> > > 收件人: "star-hp-l AT lists.bnl.gov" <star-hp-l AT lists.bnl.gov>
> > > 主题: Re: [[Star-hp-l] ] Measurement of ψ(2S) production in Ru+Ru and 
> > > Zr+Zr collisions at 200 GeV is Ready for PWG Review
> > >
> > > Hi Yan and PAs,
> > >
> > > Due to my delay in reviewing the materials, I focused on the analysis 
> > > note as the paper draft can be tuned up during the GPC if necessary. 
> > > Congratulations to you on an extremely well-written note. I have a 
> > > handful of comments below, and I find that the analysis is ready to 
> > > move to GPC formation, pending any input from Qian. I may send 
> > > comments on the paper draft at some point, but that doesn’t need to 
> > > delay the formation request.
> > >
> > > Thanks,
> > > Isaac
> > >
> > > 142. I see that after applying the procedure, there is still a 
> > > residual eta dependence although the phi dependence is nicely 
> > > removed. Is this caused by the imperfect agreement of the fit with 
> > > the data especially in the negative rapidity region? Is this non-zero 
> > > nsigma_e close enough to zero that it produces a minimal effect in 
> > > the analysis?
> > >
> > > 175. Just to make sure I understand, this cut on the invariant mass 
> > > implies that only Dalitz decays of pi0s are included in the sample, 
> > > while photon conversion typically falls just outside the requirement, 
> > > right?
> > >
> > > 204. This isn't 100% true is it? We see in the Background plot in 
> > > Fig. 11 that the track pT or p has a correlation of ~ 0.25 for 
> > > example. And this makes sense given the relation between invariant 
> > > mass and momentum. Did you check whether the results were modified 
> > > significantly if the observables which have some degree of 
> > > correlation with the pairMass were removed from consideration as 
> > > training features?
> > >
> > > Eq. 4. I understand the procedure you're following to change the mean 
> > > and sigma of the embedding nsigma distributions, but the subscripts 
> > > 1,2,3 were a little confusing to me for a second. Could you either 
> > > explicitly explain them in the text (e.g. "the numerical subscripts 
> > > refer to a value in the embedding at the corresponding step in the 
> > > correction procedure" or similar), or use a less opaque notation?
> > >
> > > 219. Sorry for this possibly silly question, but isn't there a 
> > > concern that if you use embedding for signal and data for background 
> > > that the model may distinguish the two based on some subtle 
> > > difference not between signal and background but between embedding 
> > > and data (that is left over after the feature alignment procedure)? 
> > > Was the training tried with embedding for background as well, and if 
> > > so was it approximately the same result?
> > >
> > > Fig. 15. Just curious, what is the y-axis here? Is it bin-width and 
> > > integral-normalized count? Or something else?
> > >
> > > Fig. 20. I can't tell if my eye is fooling me or not, but it looks 
> > > like the relative statistical uncertainties on the 0-80% range are 
> > > slightly bigger than the 40-80% range. Is this true?
> > >
> > > Fig. 25. What should we make of the fact that the Crystal Ball fits 
> > > are quite poor?
> > >
> > > Fig. 28. What is causing the bump ~ 500 MeV? Comparing to e.g. 
> > > https://drupal.star.bnl.gov/STAR/system/files/JianZhou_hf_20220120_v3.pdf 
> > > s. 14 [from run 16], this bump does appear but a) to a seemingly 
> > > lesser extent (for the same set of cuts), and b) with more of a 
> > > centrality dependence. Do you have an insight into the difference?
> > >
> > > > On Dec 24, 2024, at 02:04, Nihar Sahoo <nihar AT rcf.rhic.bnl.gov> wrote:
> > > >
> > > > Dear PAs,
> > > >
> > > > I have gone through the AN and paper draft. I find both the materials in 
> > > good shape, besides my following comments.
> > > > Please take a look at my comments below.
> > > > If Isaac and Qian will sign off with all these comments, then we can 
> > > request for the GPC formation around 1st week of January.
> > > >
> > > >
> > > > Title: “First observation of charmonium sequential suppression in heavy-ion 
> > > collisions at  Relativistic Heavy Ion Collider” -> “ Measurement of charmonium 
> > > sequential suppression in heavy-ion collisions at  Relativistic Heavy Ion Collider” 
> > >  [ “First …” in title sounds awkward and a reader can judge it. ]
> > > >
> > > > Line7: "We report on measurements of charmonium …” -> “We report the 
> > > measurement of charmonium …”
> > > >
> > > > L48-51: “…has  been measured in Pb+Pb collisions at …” Better to mention 
> > > what we observed at the LHC experiments and what more information we can get at 
> > > RHIC measurement and why it is important to measure at RHIC energy.
> > > >
> > > > L90-92: This sentence sounds redundant and you already mentioned in intro. 
> > > Please drop it.
> > > >
> > > > L138: “… from data for different BDT cuts, “ it is not clear from the text 
> > > what are BDT cuts. Please elaborate and avoid words like “cuts”. Use condition 
> > > or criteria, etc. [Similarly for other places]
> > > >
> > > > _ Many places “200 GeV” is used, use “ \sqrt s_NN = 200 GeV”
> > > >
> > > > _ It would be important to point out that what is advantage of using BDT/ 
> > > supervised ML technique over traditional invariant Mass combinatorial 
> > > subtraction method. A account will enhance this paper. Please indicate if such 
> > > comparisons are discussed in AN.
> > > >
> > > > _ L280-289: “While all three measurements are consistent within 
> > > uncertainties, the centrality dependence in 200 GeV Ru+Ru and Zr+Zr collisions 
> > > seem to more closely resemble the measurements at 17.3 GeV…” This is not true 
> > > within uncertainty . “…seem to more closely resemble….” Please paraphrase .
> > > >
> > > > I think it would be better to make Fig,3 as final money plot for this 
> > > paper. Whereas Fig.4 and it discussion should come before double ratio vs Npart 
> > > plot.
> > > > I find Ratio vs pT plot is less significant, due to uncertainty, than 
> > > current Fig.3 to convey the message.
> > > >
> > > > Fig.3:
> > > > _ Please add in the legend what is that gray band on unity line. It is 
> > > unclear.
> > > > _ Can we have p/d+Au 200 GeV CNM effect calculation from Tsinghua group? 
> > > That would even strengthen the claim.
> > > >
> > > > _ Is there any discussion or information on QGP Temperature from Tsinghua's 
> > > group calculation?
> > > >
> > > > Thank you
> > > > Nihar
> > > >
> > > >
> > > > On 2024-11-02 16:21, wy157543 wrote:
> > > >> Dear HPs,
> > > >> The paper draft and analysis note for “First observation of
> > > >> charmonium sequential suppression in heavy-ion collisions at
> > > >> Relativistic Heavy Ion Collider” are ready for pwg review. The
> > > >> associated documents can be found as follows:
> > > >> Webpage:
> > > >> 
> > > https://drupal.star.bnl.gov/STAR/blog/wy157543/Measurement-psi2S-production-RuRu-and-ZrZr-collisions-200-GeV-0
> > > >> Paper
> > > >> draft:https://drupal.star.bnl.gov/STAR/system/files/psi2s_paper_pwg.pdf
> > > >> Analysis note:
> > > >> https://drupal.star.bnl.gov/STAR/system/files/psi2s_note_pwg.pdf
> > > >> We would appreciate it if you could review the documents and provide
> > > >> us with your valuable comments and suggestions!
> > > >> Best regards,
> > > >> Yan for PAs