STAR HardProbes PWG

["Mooney, Isaac" <isaac.mooney AT yale.edu>]

Hi PAs,

Congratulations on getting the analysis to this stage. The paper reads very 
well, so I don’t have too many comments (see below). And I don’t have any 
substantial comments on the analysis note at this stage beyond what Nihar 
mentioned.

Thanks,
Isaac

Grammar/style/semantics/typos/nitpicks:

17. "examined" -> "accessed"; remove "of"
18. "hard probes"
20. "p+p" (and throughout)
24. "hard probes" -> "hard partons"; "their production rates" -> "the 
production rates of hard probes"
36. "nuclear shadowing"
43. "dijet" -> "leading jet" / "lead", right?
46. Remove "CNM"
56. "due to"
57. "QGP"
59. "Molière"
67. "p/d/He3+A"; Also, standard AZE notation would be "^{3}He".
69. "cut for EA" -> "selected by EA class"; could we reduce the spacing 
between bullets to a single line rather than two?
73. Remove "at both RHIC and LHC scale"
75. "...events compared to pp collisions with no EA selection."
90. Rather than the months of datataking, I would mention the total delivered 
luminosity as I think this would be more useful to the reader.
96. "...particle production and kinematics" -> "...particles and their 
kinematics"
98. Pseudorapidity and transverse momentum have already been 
introduced/abbreviated (first page), so can either use the symbol or the word 
but no need to do "word (symbol)".
99. "on" -> "in"
113. Remove "calorimeter"
115. "...from charged hadrons and other electromagnetically interacting 
particles."
119,120. "bad" and "hot" are jargon and this sentence is probably 
unnecessarily technical for the paper. Just "Of the 4800 calorimeter towers, 
318 were excluded from this analysis due to malfunctions during the data 
taking." is fine.
123. Remove quotes around "jets".
125. Prefer "< 1 - R", at least in this instance.
130. "Momentum...subtracted from...energy" is a bit weird.
138. Either "|\eta| < \pm [4.2,5.1]" or "|\eta| < [4.2,5.1] at both forward 
and backward rapidity" or "...on either side of STAR's interaction point" 
like what you have for the ZDCs. This should also be consistent with l. 177 
for the BBC.
150. "ZDC coincidence"
166. I know what you're trying to say here, but "...by the differential 
timing of the signals in the VPD" is worded a bit confusingly.
173. "High-backward-rapidity"
184. You say "In keeping with EA being correlated with centrality,..." but 
this connection hasn't been mentioned before now as far as I can tell.
190. "mid-rapidity. Thus"
191. Remove "measure of the"
192. "...per unit area in \eta and \phi."
195. Can we stick with either degrees or radians throughout?
198. I know what you're trying to get at, but aren't charged tracks also a 
"detector signal"?
203. "the STAR detector's"
220. "increases from low to high luminosity by"
227. Here, and throughout, when you quote an uncertainty, "on the order of" 
-> "of roughly" [e.g. l. 264, 270]
230. "simulated into detector signal" is awkward. Maybe "translated into"?
263. You say what it is for all but the highest pT selection, but leave this 
selection out. It should also be mentioned.
340. It's mentioned in the analysis note, but not here: why 0.9 is chosen as 
the eta selection criteria rather than 1. This would be good to add here as 
well.
Fig. 1, 2. Z-axis is missing.
Fig. 3 and throughout.
        It seems that the EA_UE notation was mostly abandoned after page 4. 
Is there a reason for this? Maybe because of the fact that the track density 
from here on is corrected? But then we could just do EA_UE^corr, right?
        The '2' of d^2N/d\eta d\phi is cut off. So is the '/c' of the legend.
        Is it really "online" E_T^trig? I'm also not sure it's necessary to 
specify online vs. offline in this caption.
        "convenience" -> "clarity"
        "for inclusive 200 GeV pp collisions"
355. "underlying event"
360. Remove "The tracks and towers are clustered into jets."
368. Remove the subscripts on each \eta
375. "for all values of jet p_T"; "The correlation"; remove "and EA".
Fig. 4. Y-axis should have a '^2' to be consistent with Fig. 3's.
382. "swing" is informal.
385. Remove the second "to".
390. "to" -> ", and"
Fig. 5.
        "N" -> "N_{dijet}" in y-axis title.
        Is "The values of ...", and including the reference to the section, 
really necessary since this information is directly above the figure and 
within the same section?
402. "within"
414. "suppresses"
Fig. 6. Legend is overlapping the border of the plot; subscript of the x-axis 
title is cut off.
423. "is related to the Q^2 of"
444. Remove "as discussed in Sec. II D"
447. The superscript is sometimes "trig" and sometimes "trigger". I thought 
for a while that it depended on whether it was online or offline, but this 
doesn't actually seem to be the case. I would recommend just "trig" 
throughout.
458. Remove "in Sec. III E"
Fig. 7.
        Isn't A_\phi defined as what you currently have |Delta \phi| defined 
as on the x-axis?
        (Also Fig. 8) The y-axis title on the ratio plot is incorrect I 
believe. Should be something like "high EA / low EA"
        (Also Fig. 8) "captions" -> "legends"
        (Also Fig. 8) "Cuts on the lower..." is unnecessary. But it would be 
helpful to write "The A_\phi distributions and ratio for jets with weaker 
(stronger) p_T requirements are shown in blue (red)." or something like that.
Fig. 8.
        "In both top and bottom panels..." -- They are?
        "convenience" -> "ease"
        This figure is smaller than Fig. 7.

Physics/structure:

40. You haven't explained what event activity is at this point. You could 
probably squeeze it in around l. 28 where you mention Au+Au collisions, by 
specifying that we see effects in central (or high-event-activity) Au+Au. Or 
since I think you should have a bit of space before hitting PRC's limit, and 
since it's central (no pun intended) to the paper, you could spend a bit more 
time on it.
45. Without the context that you give later, I don't think a small systems 
non-expert would fully understand the motivation for studying this 
correlation between the hard and bulk processes. I would either talk about 
the spatial separation pointing to early-time dynamics (similar to the last 
sentence of the abstract) or move the bulleted measurement history before 
your description of these measurements, so you can more easily showcase the 
contribution of this paper to our overall understanding of small systems; or 
both.
48. This paragraph is a bit isolated, and the motivation for the measurement 
is also not given.
52. If I'm wrong about my comment on l. 43 and you keep "dijet" there, then 
this explanation of dijets should go before that.
54. Modification of AJ and Aphi could conceivably be due to final state cold 
nuclear matter effects, e.g. bremsstrahlung or multiple scattering in a cold 
nucleus, right? So here I would remove "from QGP jet quenching". Also on l. 
57 and 59 change "in the QGP" to "in the medium". If you did want to 
highlight the potential to test specifically for QGP in small systems, I 
would add a sentence somewhere claiming that cold nuclear matter effects on 
jets are expected to be negligible (and some citation backing it up), and 
then give some quick mention of other hints of HNM effects in small systems 
and references to the measurements (e.g. the PHENIX vn, the ridge(s) in 
high-multiplicity pPb (and pp) + strangeness enhancement at LHC, etc.).
99. You say that tracks above 30 GeV are discarded, but it's actually the 
events containing these tracks that are discarded, right?
131. Can we use ref. 23 as justification since they were looking at 
JP2-triggered jets? Maybe there isn't a large difference, but I don't have a 
good feel for it. Have you looked into it? Also, from looking at your 
analysis note, it seems that you do include a variation of the hadronic 
correction as a systematic for the spectra at least, so it would be good to 
mention here as well that it enters into systematics. And while I have ref. 
23 pulled up and I'm thinking about it, do you also have a selection on the 
jet NEF of < 0.9 or < 0.94? I couldn't find it in the analysis note.
259. You should point out the min. jet pT here to give context.
319. Except for the tails, where the monotonicity is broken. E.g. EA_UE of 
0-0.4 in Fig. 1.
344. You haven't mentioned yet that Fig. 3 has selections on E_T^trig, so 
it's not clear what is doing the bounding/why it's track densities, plural.
348. To me, "peripheral" is a statement about geometry. It should be avoided 
here, even in scare quotes. How about just "low-EA_BBC p+Au collisions are 
pp-like."? Similar comment for l. 472.
474. Is there a way that I can get this conclusion directly from the paper, 
other than by roughly eyeballing Figs. 3 and 4?
515. The paper ends fairly abruptly. It's missing some connection back to the 
literature mentioned on the first page, and/or broader takeaways / 
implications for future studies.

> On May 9, 2023, at 9:46 AM, Nihar Sahoo via Star-hp-l 
> <star-hp-l AT lists.bnl.gov> wrote:
>
> Hello PAs,
>
> Glad to see this analysis at this stage.
> I tried to go through the paper draft and analysis note.
> I know this paper draft will go through multiple review process (hp 
> pwg-GPC-Collab) in coming days and my comments are probably zero-th stage 
> now.
>
> Please find my comments on your paper draft and AN below.
>
> Paper draft:
>
> $pp$ -> $p+p$ make consistent thought out the paper as $p$+A
>
> L18-20: "These include high-pT hadrons and, in the case of this 
> publication, jets (refer to Section II)." It reads awkward in this 1st 
> para. Better to introduce the topic with out mentioning "…n the case of 
> this publication, jets (refer to Section II)."
> L26: "…with other matter throughout …" -> you have not discussed yet what 
> is matter?
> L24-30: Too big and complicate complicate sentence. Please break it.
> L32: "measurements of √sNN = 200GeV d+Au collisions have provided an 
> important connecting role …" Here it reads like we are measuring "√sNN = 
> 200GeV d+Au collisions". That is not true. Rephrase like "At STAR, jet 
> measurements at √sNN = 200 GeV in d+Au collisions provide important 
> information of cold nuclear matter …"  something like this.
> L36-39: "In this publication, we present measurements from √sNN = 200 GeV 
> p+Au collisions provided by RHIC in 2015 and measured at STAR."   Unclear 
> and redundant sentence.
> L39: Specifically,  -> No needed.
> L41: high-η -> so far "η" is not defined ; same for φ_{}
> 2nd para: "we present…" and "we report" are used in multiple instants. 
> Please try to rephrase at then end what "we present/report …" in this paper.
> L52: "To first order, hard scatterings result in azimuthally  back-to-back, 
> pT-balanced dijet pairs. " It reads this is a collection of words; please 
> make a sentence. L54-60: This sentence needs work. Syntax doesn't read well.
> L63-67: Rephrase this sentence and provide reference to PHENIX, ATLAS, 
> ALICE, CMS measurements.
> L67-68 and all bullets: No need to summarize what we observed in p/d/He^3 
> collisions. It would be better to emphasize what we try to measure in this 
> publication and what is our current understanding pertaining to it.
>
> Overall, I think this introduction section needs work to  be precise and 
> coherent.
> At the end of this section, we need a paragraph mentioning a brief overview 
> of other sections.
>
> Section- II.A
>
> L89: "…provided sNN = 200GeV p+Au collisions…" -> …provided p+Au collisions 
> data at sNN = 200 GeV in 2015." (No need to write May and June)
> L91: "This publication reports collisions measured by STAR (Solonoid 
> Tracker at RHIC). Events were selected and measured using the following 
> STAR sub-detectors." -> Make it one sentence. Otherwise drop it as it is 
> not adding any info here.
> L100: (> 30 GeV/c)…(poor pT resolution),-> better to avoid this style of 
> writing. Explicitly mention this in one sentence.
> L107: "…20 hits in the TPC …" -> "…charged-tracks with at least 20 hits…"
> L113-115: "The BEMC calorimeter measures principally photons from π0 decays 
> and, in less abundance, interactions from charged hadrons." -> "The BEMC 
> calorimeter measures the energy deposition of electromagnetically 
> interacting particles."
> L115-118:"Only calorimeter hits with transverse energy projections (ET) 
> within the selected pT range ([0.2,30] GeV) were considered in this 
> analysis."  Not sure what  does it want to say.  L118-121: For reader, what 
> are "bad online" and "hot towers" ?
> L122:" …tracks and towers are combined …" -> "…tracks and towers are 
> clustered …" ; "R = 0.4 resolution parameter." -> a resolution parameter 
> R=0.4.
> L136: "STAR selected minimum bias (MB) collision events triggered online by 
> the Vertex …" -> "The minimum bias (MB) events are selected using the 
> Vertex …"
> L141: "…at least 2.5 GeV. " ->  is  the BHT1 or BHT0 trigger used in this 
> analysis?
> L143: "HT events is raised to 4GeV as an offline event cut"  -> however In 
> "main_AN_v0.pdf"  L196, offline cut is used ET > 8 GeV and In 
> "AN_vv_v0.pdf" L24: ET>4 GeV is used. Please make it consistent or explain.
> L146: "STAR’s interaction point, " -> is it center of the TPC? [same for 
> L164]
> L154: "(PU)…(tracks not resulting from particles involved in the collision 
> being measured) " this is important for this paper so mention it in a 
> separate sentence.
> L162: "triggered collision" what is triggered collisions?
> L165: "Second, Vz was required… VPD… to the TPC" Please mention why we need 
> this second condition for selecting events? For example to reduce pile up 
> events, … etc.
> L170: "reports on measurements from 3.7 mil- lion MB and 135 million HT 
> collisions. " -> This sentence doesn't mention what do we report?  What 
> observables and why?
>
> L173: "High-backward rapidity " provide eta range.
> L195:  φUE  and  φlead are not defined.
> L193: "…      .       in MB events, however, …" -> "…in MB events. However, 
> …"
>
> Section-II.B
>
> L202: "Detector track efficiency and acceptance are …" -> "The TPC tracking 
> efficiency within a given acceptance is …" L215: "using pp relative 
> weightings is small" -> mention what is that number is ?
> L219-222: "After correcting for the tracking efficiency, the average number 
> of tracks in the TPC increases by about 0.5 tracks (…)" -> "Increase by 
> about 0.5 tracks " depending on EA or lumi.  not clear.
> L222: "This increase is attributed to pileup tracks …" why it is the only 
> possibility? Due to high lumi, efficiency drops that doesn't mean due to 
> pileup tracks. Am I misunderstood?
> L232: "zero-bias (randomly triggered) events" -> Not clear if it is 
> embedded in "zero-bias" p+p or p+A events?
> zero-bias events are not "randomly triggered" event? It is without (hence 
> zero) any detector condition.
> Question: if it is pp zero-bias, then how do you implement pAu event 
> background fluctuations while unfolding the jet spectrum?
> L33: PYTHIA6 level particles  -> "Generated level PYTHIA-6 particles…" ; 
> "the simulated track and tower responses " -> the GEANT3 level simulated 
> track and tower responses …"
>
> Additional comments: please mention what is the jet matching efficiency in 
> pAu ? And what about JER and JES.
>  L259-262: "Note that there are no jets in the pT range of the reported… 
> unity". Not clear, please rephrase or explain here.
>
>
> Section: II.D
> L277-279: "The shape of the azimuthal distribution between the leading and 
> subleading jets" -> Mention how do you normalize this distribution. Define 
> what is A_phi? I think it is certainly not "Aφ ≡ |φlead − φsub|) "?
> L289-290: "This justifies the presentation of detector-level Aφ and AJ 
> distribution ratios as meaningful." -> this is true for ratios. For Fig.7 
> and 8, But for upper panel plots the shapes are not corrected and may not 
> help for any theory comparison in future study. This is a weak point of 
> this paper and Referee/Collaboration will be critic of it.
>
> L323-326: "   While this publication focuses on correlations with EA_BBC, 
> given its monotonicity with EA_UE, there is no physical preference for one 
> definition of EA over the other. " I think we should give preference to one 
> of EA definitions (probably here EA_BBC) and that should be decided how 
> well we can discriminate the EA classes. For example in centrality 
> definition, we decide based on centrality resolution. Similarly we need to 
> mention why we choose EA_BBC and based on what? See my comment below on 
> this topic.
> L328: the lowest and highest 30% in MB define the ranges of EALow and BBC 
> EA_High , respectively (see Sec. II A 3). And cf. Fig.1 -> 30%, 40%, 30% 
> labels are not clear.
> In this section.III.A , we need to have a discussion on this EA_BBC 
> definition, how well we can discriminate different event classes. i.e. is 
> there any overlap of events between EA_BBC^High and EA_BBC^low classes?
>
> section.III.B:
> L341: "…plotted in Fig. 3 for ten ranges of EABBC. " and Fig.3 -> As I 
> mentioned above, it is difficult using EA_BBC we can really divide 10 EA 
> classes as shown in Fig,3. There must be large fraction of events 
> overlapping adjacent EA_BBC bins.
> In this section, it is not clear why we have Fig.3? What do we learn from 
> this fig? And why do we have 10 ranges of EA_BBC?
>
> section.III.C:
>
> L352: "while Fig. 3 suggests that the underlying event is anti-correlated 
> with increasingly energetic triggers." Not clear how do we draw this 
> statement from Fig.3? What I can see that within uncertainty all three HT 
> trigger cases are consistent with MB.  Am I missed anything?
> L363: "i.e. |φtower −φjet | > (180◦ −Rjet ). " Please correct it. 180-Rjet?
>
> Section.III.D
>
> L402:  and withing -> and within
> L405: jets will fall outside -> jets fall outside L409 and L411 don't say 
> anything about the reason of this suppression. This suppression discussion 
> sounds like incomplete and hastily stopped at this point.
>
> Section.III.E
>
> L452: Definition of A_phi is different from phi difference. See Fig.7 upper 
> panel Y-axis title.
>
>
> _____
> Comments on Figures:
> General: Make x-, Y-axis title and label clearly visible and make font size 
> of legend/title/label  bigger.
> Put  "STAR" in every figure.
>
> Fig-3:  Y-axis title in d^2 , "2" is missing. Please increase this size of 
> this figure. Fig-7: Make Y-axis log scale so that each data point can be 
> visible
> Fig.6: Y-axis title, should it be d^2N/dpT dphi?
> Fig.6, 7, 8,: Mention System, energy in legend
>
> In Fig7 and 8 caption: "Cuts on the lower bounds of pT,jet and  psub are 
> indicated in captions." Not sure what "caption"?
>
>
> —————
> General comment: Can you please add these two analysis notes into one so 
> that it would be easy for the reader?
>
> main_AN_v0.pdf
>
> 1. Can you please work on the proper alignment of figures in this AN? It 
> looks awkward.
> 2.  Section. 3.2: in p+Au events, eta-distribution is not uniform (flat) at 
> mid rapidity. Have you checked the difference between EA_TPC for both the 
> configurations like p-going side and Au-going sides eta-distributions and 
> what is the difference between EA_TPC?
> 3. Fig.9 and 10: put Y-axis title;  In caption:"The mean values of each EA 
> definition in bins of the other EA definition are also plotted."- > This is 
> event-by-event of 2D histogram. Then not sure "the mean value of each EA… 
> are also plotted" Can you please clarify?  "Statistical errors on the mean 
> are shown." -> No stat. Errors are shown.
> 4. IN fig 9 and 10: no mean values are plotted, I think. Please use correct 
> plots.
> 5. Section 3.3: "     Correlation Between EA_BBC and EA_TPC " -> But in the 
> texts you mention EA_UE. So far you have not introduced EA_UE?
> 6. Fig.16,18, 20, 37, 38,39,40,43,44,45,46,47,52: No data shown in this 
> plot. Please use correct plot. Check also other.
>
>
> Best
> Nihar
>
>
>
>
>
>> On 2023-04-28 12:10, David Stewart via Star-hp-l wrote:
>>> Hi all,
>>> This is just a reminder in the middle of the flood of QM work/emails
>>> that the draft and analysis notes for our p+Au EA vs UE vs jet paper
>>> are posted on the paper webpage here [1] and that we are ready and
>>> waiting for GPC formation.
>>> Thanks,
>>> David Stewart
>>> Postdoctoral Fellow | Department of Physics, Wayne State University
>>> Links:
>>> ------
>>> [1] 
>>> https://drupal.star.bnl.gov/STAR/blog/djs232/Paper-EA-and-UE-Corrs-High-Q2-Events-pAu-sNN200-GeV-Collisions-STAR
>>> _______________________________________________
>>> Star-hp-l mailing list
>>> Star-hp-l AT lists.bnl.gov
>>> https://lists.bnl.gov/mailman/listinfo/star-hp-l
> _______________________________________________
> Star-hp-l mailing list
> Star-hp-l AT lists.bnl.gov
> https://lists.bnl.gov/mailman/listinfo/star-hp-l